Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Sun, Feb 27, 2011 at 10:29:35AM +0100, Remy CLOUARD wrote: Here are a few issues I encountered: - grub entry might be wrong you could end up with root=/dev in the kernel line instead of /dev/vg/lv, bug not opened yet because I haven’t been able to trigger the condition to encounter it. there should be a mdv bug about that, i think i opened it 2 or 3 years aho. - initrd might be wrong if crypttab is empty (should open a bug for this) - lvm might not be correctly detected and not included in initrd: I had to export VG_LIST="vg" to get it work as expected still using mkinitrd? L. -- Luca Berra -- bl...@vodka.it
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Mon, Feb 21, 2011 at 01:39:32PM +0100, Anne nicolas wrote: > Apart from all possible issues, diskdrake needs first to be improved. > Looking on partitions when you run LVM still needs to have knowledge > about how it works. And I really don't think people can easily > understand PV, VG, LV and FS > -- > Anne > http://www.mageia.org I would like to wave in this direction. Enabling lvm by default would be a bit premature at the moment, but one thing we could add is the ability to choose this layout, like what debian does. You can choose to have lvm, but are not forced to. At the moment we provide 3 layouts: - simple - simple with /usr - server We could have other ones like: - /boot + lvm -> will hold /, swap, /home with extra space saved - /boot + lvm + encrypt At the moment there is one major blocker for lvm, if one check the encrypt checkbox, one gets screwed, see https://bugs.mageia.org/show_bug.cgi?id=188 I’ve been using lvm here for quite a long time on mandriva, it works great but I still have to do manual things to get things right. Here are a few issues I encountered: - grub entry might be wrong you could end up with root=/dev in the kernel line instead of /dev/vg/lv, bug not opened yet because I haven’t been able to trigger the condition to encounter it. - initrd might be wrong if crypttab is empty (should open a bug for this) - lvm might not be correctly detected and not included in initrd: I had to export VG_LIST="vg" to get it work as expected And we have to test it thoroughly first ! Regards, -- Rémy CLOUARD () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments pgpqICnDX5l17.pgp Description: PGP signature
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Frank Griffin a écrit : Wolfgang Bornath wrote: Now with LVM, what do I do? Pretty much exactly the same, if that's what you want. LVM is just a layer of indirection that you place on top of *only* those partitions you want LVM to control. It lets you create multiple "virtual" partitions each of which includes one or more physical partitions. In the minimal case, you can partition exactly as you would without LVM, but make each of the Mageia partitions an LV formatted as ext4 (or whatever) rather than a physical ext4. The difference is that later on if you need to expand one of these 1-1 LVM partitions, all you do is create another physical partition *somewhere* - either on that physical disk or another you add - and tell LVM to make that new physical partition part of the LV you want to expand. The original physical partition on which you based the LVM stays exactly where it is without change, and the Logical Volume just magically increases in size by the size of the new physical partition you added. Using LVM for some or all of Mageia has no effect on your ability to use standard partitioning for other partitions on these disks. It occurs to me that LVM (which I have only tested a long time ago) would play nicely on a large disk with a gpt partition table. Just divide the disk into a lot of reasonably-sized partitions (the limit for a default gpt table is 128 (primary) partitions, and let LVM combine them as appropriate, being dynamically reassociable as needed. Then if you want to do a clean install of a new Mageia (or other) release, could you just reformat the partitions you want (excluding /home and whatever other partitions you want to keep), without problem with LVM ? If so, that would be nice. The trick of course would be to ensure that you assign directories to partitions in an appropriate manner. some random thoughts ... :) -- André
Re: [Mageia-dev] time to switch from raw partitions to lvm?
2011/2/25 Maarten Vanraes : > Op donderdag 24 februari 2011 14:19:54 schreef Frank Griffin: >> Wolfgang Bornath wrote: >> > Now with LVM, what do I do? >> >> Pretty much exactly the same, if that's what you want. LVM is just a >> layer of indirection that you place on top of *only* those partitions >> you want LVM to control. It lets you create multiple "virtual" >> partitions each of which includes one or more physical partitions. In >> the minimal case, you can partition exactly as you would without LVM, >> but make each of the Mageia partitions an LV formatted as ext4 (or >> whatever) rather than a physical ext4. >> >> The difference is that later on if you need to expand one of these 1-1 >> LVM partitions, all you do is create another physical partition >> *somewhere* - either on that physical disk or another you add - and tell >> LVM to make that new physical partition part of the LV you want to >> expand. The original physical partition on which you based the LVM >> stays exactly where it is without change, and the Logical Volume just >> magically increases in size by the size of the new physical partition >> you added. >> >> Using LVM for some or all of Mageia has no effect on your ability to use >> standard partitioning for other partitions on these disks. > > don't forget that a filesystem on top of this, still has to be resized as > well... Can it be that LVM is not yet possible with Mageia? I did a beta 1 installation yesterday for other testing reasons and did not find any button or whatever in diskdrake which said "LVM" or similar. May be I overlooked it... -- wobo
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Op donderdag 24 februari 2011 14:19:54 schreef Frank Griffin: > Wolfgang Bornath wrote: > > Now with LVM, what do I do? > > Pretty much exactly the same, if that's what you want. LVM is just a > layer of indirection that you place on top of *only* those partitions > you want LVM to control. It lets you create multiple "virtual" > partitions each of which includes one or more physical partitions. In > the minimal case, you can partition exactly as you would without LVM, > but make each of the Mageia partitions an LV formatted as ext4 (or > whatever) rather than a physical ext4. > > The difference is that later on if you need to expand one of these 1-1 > LVM partitions, all you do is create another physical partition > *somewhere* - either on that physical disk or another you add - and tell > LVM to make that new physical partition part of the LV you want to > expand. The original physical partition on which you based the LVM > stays exactly where it is without change, and the Logical Volume just > magically increases in size by the size of the new physical partition > you added. > > Using LVM for some or all of Mageia has no effect on your ability to use > standard partitioning for other partitions on these disks. don't forget that a filesystem on top of this, still has to be resized as well...
Re: [Mageia-dev] time to switch from raw partitions to lvm?
2011/2/24 Frank Griffin : > Wolfgang Bornath wrote: >> Now with LVM, what do I do? >> > Pretty much exactly the same, if that's what you want. LVM is just a > layer of indirection that you place on top of *only* those partitions > you want LVM to control. It lets you create multiple "virtual" > partitions each of which includes one or more physical partitions. In > the minimal case, you can partition exactly as you would without LVM, > but make each of the Mageia partitions an LV formatted as ext4 (or > whatever) rather than a physical ext4. > > The difference is that later on if you need to expand one of these 1-1 > LVM partitions, all you do is create another physical partition > *somewhere* - either on that physical disk or another you add - and tell > LVM to make that new physical partition part of the LV you want to > expand. The original physical partition on which you based the LVM > stays exactly where it is without change, and the Logical Volume just > magically increases in size by the size of the new physical partition > you added. > > Using LVM for some or all of Mageia has no effect on your ability to use > standard partitioning for other partitions on these disks. Thx for the explanation. I'll save that (with some extensions) for reference to forward to users if Mageia really switches to LVM as default. -- wobo
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Wolfgang Bornath wrote: > Now with LVM, what do I do? > Pretty much exactly the same, if that's what you want. LVM is just a layer of indirection that you place on top of *only* those partitions you want LVM to control. It lets you create multiple "virtual" partitions each of which includes one or more physical partitions. In the minimal case, you can partition exactly as you would without LVM, but make each of the Mageia partitions an LV formatted as ext4 (or whatever) rather than a physical ext4. The difference is that later on if you need to expand one of these 1-1 LVM partitions, all you do is create another physical partition *somewhere* - either on that physical disk or another you add - and tell LVM to make that new physical partition part of the LV you want to expand. The original physical partition on which you based the LVM stays exactly where it is without change, and the Logical Volume just magically increases in size by the size of the new physical partition you added. Using LVM for some or all of Mageia has no effect on your ability to use standard partitioning for other partitions on these disks.
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Ok, seems I will have to learn a new way of working after getting along for many years with many Linux flavors very well. Say, with a new laptop which has a 360 Go harddisk with Windows preinstalled - which is one of the top most user cases: 1. I start windows, move everything from D:\ to C:\ (if there is a D:\), then check/defrag C.\. 2. I restart the laptop with the Mageia install medium and start installation. Normally (with diskdrake during installation) I'd resize the Windows partition to 20 Go, then create swap on sda5, a large Data partition (150Go or more) on sda6 and the root partition of Mageia (10 Go) on sda7. The rest remains untouched. (A dynamic extended partition sda2 (or 3 or 4) is created automatically by diskdrake). 3. If I feel like install another Linux or another instance of Mageia I just create sda8 in the free space, etc. Now with LVM, what do I do?When installing Mageia I don't create those partitions but just one large LVM which holds DATA, swap and root partition of mageia? But I want to use swap and DATA with all other Linux installations as well, how do I mount them into another LVM? Is it possible to have another LVM for Mandriva, another one for Fedora, etc. all inside the extended partition sda4? Now, I am totally aware that this thread is not for answering such questions and I will read up on LVM ASAP. What I want to show with this common example is: many users will ask these questions because (AFAIK from my forum experience) most users do not use LVM yet. -- wobo
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On 24 February 2011 13:28, Thierry Vignaud wrote: >>> - If you've a small 8Go partition at start of the disk followed by one To >>> partition and you want to increase the first one, you're screwed without >>> LVM >>> With LVM, you can just got some free space from anywhere (even another >>> disk) >> >> You can do that with symbolic links if you don't want to resize the >> partitions. > > quick & dirty workaround. hardly a real solution... > and if you have one directory that is too big to move in any of the > available partition, > you are still stuck, whereas with lvm you can shrunk every fs and the > all all of the small > space just freed into the fs that needs it what's more that just asking for issues eg: - urpmi or rpm starting a rpm transaction that failed in the middle because part of /usr/lib/*/ is in fact on another partition thanks to soft link - system stuff (at least those not running as root) having faillure b/c /home/joe just filled / despite being on a separate mount moint thanks to softlink - ...
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On 24 February 2011 06:06, andre999 wrote: >> It's not as easy as LVM (need to use a partitionner). >> Diskdrake and the like will force you to umount the partitions to resize >> which may needs to boot on a rescue CD (eg for resizing / fs) >> It may not be possible ie: > > A rescue CD like Sysrescuecd is easy to use and comes with all the tools > needed. > It would be nice if the rescue option of the eventual release Mageia dvds > contained the few utilities necessary for this. that's not the point: you still have to reboot in order to resize some fs whereas, at least you have to umount them with graphical tools. whereas with lvm you can resize fs online, without umounting anything, without rebooting;. >> - you already have 4 primary partitions and none of them is an extended >> one. > > A gpt partition table solves this problem. which nearly nobody use, hence it's irrelevant. The 99.99% of users who are using partitions are still stuck with the problem. >> - If you've a small 8Go partition at start of the disk followed by one >> To partition >> and you want to increase the first one, you're screwed without LVM >> With LVM, you can just got some free space from anywhere (even another >> disk) > > You can do that with symbolic links if you don't want to resize the > partitions. quick & dirty workaround. hardly a real solution... and if you have one directory that is too big to move in any of the available partition, you are still stuck, whereas with lvm you can shrunk every fs and the all all of the small space just freed into the fs that needs it >> - one can live resize (w/o umouting/remounting) >> >> - one can use snapshots in order to rollback dangerous update >> (eg: for trying initscript -> systemd switch, ...) >> >> I think it brings many usefull features. >> Those who don't want LVM could still do manual partitionning. > > These seem to be mostly enterprise-oriented factors, unless I'm missing > something. > For now at least, I prefer manual partitionning to be the default. easy rollbacking after a disastrous update to a new xserver, a new boot system, ... is appealing for cooker users. live resizing for freeing space in order to set up a vm on top of block device (yes you can still use a file loopback but this is cleaner) being able to live resizing fs in order to move free space where it's needed before eg: doing a big backup, copying those 3 dvds of the mariage the wife wants to be saved, ... without rebooting is appealing to anyone
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Anne nicolas a écrit : 2011/2/21 Michael Scherer: Le lundi 21 février 2011 à 10:56 +0100, Wolfgang Bornath a écrit : Another part of the discussion may be the fact that a large number of users are running dual (or multiple) boot systems, keeping the pre-installed Windows and adding Linux. Others will have Windows and Mandriva, adding Mageia. While LVM may be nice if you are running one OS on one harddisk, it may be not so easy when running 3 OS on one harddisk. Or different installations of the same Linux (like stable version and cauldron). I do run lvm on Fedora and mac os x without any trouble. Windows will not support any linux file system more than lvm, and the same goes for os x. For a linux system, a lvm logical volume is just another disk. Apart from all possible issues, diskdrake needs first to be improved. Looking on partitions when you run LVM still needs to have knowledge about how it works. And I really don't think people can easily understand PV, VG, LV and FS One thing that needs to be fixed in diskdrake : Although it recognizes and works with standard gpt partition tables -- an alternative to the usual mbr partition tables -- it doesn't work properly with hybrid gpt tables. (A version of gpt that allows dual-booting with ms-w.) Gpt is inherently more stable than mbr, and the standard version allows 128 primary partitions -- in less space than normally wasted in a disk with an mbr table. -- André
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Thierry Vignaud a écrit : On 21 February 2011 08:51, P. Christeas wrote: What do you think about switching from defaulting to installing on raw partitions to lvm installing on LVs like fedora does ? I vote against that. (=to be enabled by default) LVM is fine for "enterprise" setups, or better, installations where the (expert) admin will need to resize/move partitions in the future. But, for simple machines/users, the complexity of having LVM is IMHO not worth it. (remember also that on all *nix OSes, you can just add a partition, move some files like /usr/share/doc into it and then mount it on /usr/share/doc, thus freeing /usr of some space. No LVM, no virtualization, no ZFS required) It's not as easy as LVM (need to use a partitionner). Diskdrake and the like will force you to umount the partitions to resize which may needs to boot on a rescue CD (eg for resizing / fs) It may not be possible ie: A rescue CD like Sysrescuecd is easy to use and comes with all the tools needed. It would be nice if the rescue option of the eventual release Mageia dvds contained the few utilities necessary for this. - you already have 4 primary partitions and none of them is an extended one. A gpt partition table solves this problem. Standard gpt allows 128 partitions in less space than is typically used with an mbr partition table with an extended partition. As well, there is a backup partition table at the end of the disk, so it is inherently more reliable. - If you've a small 8Go partition at start of the disk followed by one To partition and you want to increase the first one, you're screwed without LVM With LVM, you can just got some free space from anywhere (even another disk) You can do that with symbolic links if you don't want to resize the partitions. Although I wouldn't partition a disk like that in the first place. (I prefer dividing a disk into a least several partitions. I have 8 on my current system.) What's more, one gains many features: - snapshots (yes snapshots for sql db backups are not for end users) but still usefull for saving the whole system at one fixed time - you can extend some filesystems from space from other disks - it's easier to add space where needed when defaults partitions sizing proved to be altered after some usage - one can live resize (w/o umouting/remounting) - one can use snapshots in order to rollback dangerous update (eg: for trying initscript -> systemd switch, ...) I think it brings many usefull features. Those who don't want LVM could still do manual partitionning. These seem to be mostly enterprise-oriented factors, unless I'm missing something. For now at least, I prefer manual partitionning to be the default. -- André
Re: [Mageia-dev] time to switch from raw partitions to lvm?
- "Thorsten van Lil" wrote: > Am 22.02.2011 09:07, schrieb Buchan Milne: > > > The user will still *always* be able to decide what he wants. The > question is, what to do for users who don't know what to decide. IMHO, > for a first time user, it is *much* better to give them a "Use > available space, with growable filesystems" or similar, than a > statically partitioned, based on difficult-to-get-right heuristics. > > > > That's a good point. The step for partitioning is still the most > complex > one during the installation. There are really often questions and > discussions how to partition the hard disk. Exactly. Dispensing with this requirement would make installation much easier, and still put the user in a position where they aren't setup for failure (all other solutions do, IMHO). > But, as a user who doesn't know anything about LVM, we should only > switch if the algorithm for LVM works really really stable and is easy With static partitions, the heuristics have to be good. For LVM, they just have to: -Ensure enough space for installation to succeed -Ensure a large percentage of the VG is not allocated (as growing is easier than shrinking) > to use. > It seems to me positive to switch to LVM for default but it's not > really > important, You obviously haven't seen how many users have questions about shrinking / from 50GB because they need more space for /home, or similar questions, on IRC. > so we don't should risk to much and take the time it needs, > > instead of forcing it to be finished for the next release, for > example. I listed the issues that I believe block switching to LVM by default. If they are fixed, I would think it would be an idea to launch the first stable release with LVM by default. Regards, Buchan
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Am 22.02.2011 09:07, schrieb Buchan Milne: The user will still *always* be able to decide what he wants. The question is, what to do for users who don't know what to decide. IMHO, for a first time user, it is *much* better to give them a "Use available space, with growable filesystems" or similar, than a statically partitioned, based on difficult-to-get-right heuristics. That's a good point. The step for partitioning is still the most complex one during the installation. There are really often questions and discussions how to partition the hard disk. But, as a user who doesn't know anything about LVM, we should only switch if the algorithm for LVM works really really stable and is easy to use. It seems to me positive to switch to LVM for default but it's not really important, so we don't should risk to much and take the time it needs, instead of forcing it to be finished for the next release, for example. Just my concerns to this topic. Regards, Thorsten
Re: [Mageia-dev] time to switch from raw partitions to lvm?
- "Wolfgang Bornath" wrote: > 2011/2/21 Buchan Milne : > > On Monday, 21 February 2011 11:49:27 Thomas Lottmann wrote: > >> I am still not convinced of how easy this can be. For having > attempted > >> to manage (and learn) how to manage LVM partitons with CentOS, it > is > >> quite complicated. So it certainly has many advantages, but I'm > awaiting > >> an intuitive disk manager like Diskdrake to manage this stuff > without > >> the need of preliminary knowledge. > > > > Yes, with diskdrake, it's no problem. Anaconda's LVM interface is > quite > > confusing and complex. After installation, AFAIK, you can't access > the same > > interface. system-config-lvm (if it's still around) was also pretty > unusable. > > > > But, we have diskdrake, so why are the problems of CentOS an issue? > > Because (as I remarked earlier) there are people who have other Linux > flavors on their harddisk before they try Mageia - what if they do > their partitioning with those (i.e. CentOS)? Irrelevant. If there is free space, you can use LVM or not. Note CentOS defaults to LVM as of 5.x. If the whole disk is partitioned as a PV (likely with CentOS), then you will be forced to use LVM anyway ... > Again, people do not work all the same. Irrelevant. If this was the case, we would *FORCE* everyone to use LVM, or a large single root filesystem, or a complex layout, or something else. But we aren't discussing forcing of anything, just what the *default* option should be. > There are people who do their > partitioning with 3rd-party apps like gparted or others. Then they should not use the default, if they think they know better. > There are > people who like to have a bootloader in the root partition of each > Linux they install (using chainloader in the first Linux' grub), etc. Shame, IMHO putting bootloader in root partition is a bad idea. But, they can still do this. They can even install a bootloader in the boot partition of each distro, and use chainloader (which is what I do). No one is proposing preventing them from doing this. > IMHO it is a bad idea to make LVM default, because there are too many > cases around where people would not want LVM. IMHO, the majority of users *should* use LVM. The 10% who have specific reasons not to, will of course still be able to use normal partitions. The problem currently is that I suspect 90% of the users who should be using LVM, don't. Then, they need assistance from others to resize their /, or /home, or another filesystem that they sized incorrectly during installation. Users shouldn't need to "learn to partition", or "practice installing", by doing installations over and over until they figure out that / should be at least 10GB, but most likely not larger than 30GB, depending on whether they compile a lot (e.g. build packages or not). Is this really user-friendly? By this I mean, friendly to users who *haven't* used Linux before, not those who are installing their 10th distro on the same machine for the 15th time. > LVM as an option is a > far better solution and let the user decide what he wants. The user will still *always* be able to decide what he wants. The question is, what to do for users who don't know what to decide. IMHO, for a first time user, it is *much* better to give them a "Use available space, with growable filesystems" or similar, than a statically partitioned, based on difficult-to-get-right heuristics. Regards, Buchan
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Le mardi 22 février 2011 à 03:36 +0100, Wolfgang Bornath a écrit : > 2011/2/21 Buchan Milne : > > On Monday, 21 February 2011 11:49:27 Thomas Lottmann wrote: > >> I am still not convinced of how easy this can be. For having attempted > >> to manage (and learn) how to manage LVM partitons with CentOS, it is > >> quite complicated. So it certainly has many advantages, but I'm awaiting > >> an intuitive disk manager like Diskdrake to manage this stuff without > >> the need of preliminary knowledge. > > > > Yes, with diskdrake, it's no problem. Anaconda's LVM interface is quite > > confusing and complex. After installation, AFAIK, you can't access the same > > interface. system-config-lvm (if it's still around) was also pretty > > unusable. > > > > But, we have diskdrake, so why are the problems of CentOS an issue? > > Because (as I remarked earlier) there are people who have other Linux > flavors on their harddisk before they try Mageia - what if they do > their partitioning with those (i.e. CentOS)? Well, if they have already partitions to reuse ( ie, ex centos partition ), they will just reuse them without lvm and that's all. And if they do not have any partition to reuse, or just a part of the disk, we are in the same case, there is free space and we can use it as we want. > Again, people do not work all the same. There are people who do their > partitioning with 3rd-party apps like gparted or others. There are > people who like to have a bootloader in the root partition of each > Linux they install (using chainloader in the first Linux' grub), etc. And what exactly would be broken with lvm and theses schemes ? Arguments based on "there is some special cases that would requires special care" are not very helpful if the special case is not described in details, and we cannot have technical discussion based on imprecise input. > IMHO it is a bad idea to make LVM default, because there are too many > cases around where people would not want LVM. LVM as an option is a > far better solution and let the user decide what he wants. Making it be default doesn't mean that the user cannot decide to opt out, this argument do not seems very strong. This is a default, not something that would be forced to use. And this is not a all or nothing, you can perfectly have a partition in the lvm, and one outside ( or several, or any mix you want ). -- Michael Scherer
Re: [Mageia-dev] time to switch from raw partitions to lvm?
2011/2/21 Buchan Milne : > On Monday, 21 February 2011 11:49:27 Thomas Lottmann wrote: >> I am still not convinced of how easy this can be. For having attempted >> to manage (and learn) how to manage LVM partitons with CentOS, it is >> quite complicated. So it certainly has many advantages, but I'm awaiting >> an intuitive disk manager like Diskdrake to manage this stuff without >> the need of preliminary knowledge. > > Yes, with diskdrake, it's no problem. Anaconda's LVM interface is quite > confusing and complex. After installation, AFAIK, you can't access the same > interface. system-config-lvm (if it's still around) was also pretty unusable. > > But, we have diskdrake, so why are the problems of CentOS an issue? Because (as I remarked earlier) there are people who have other Linux flavors on their harddisk before they try Mageia - what if they do their partitioning with those (i.e. CentOS)? Again, people do not work all the same. There are people who do their partitioning with 3rd-party apps like gparted or others. There are people who like to have a bootloader in the root partition of each Linux they install (using chainloader in the first Linux' grub), etc. IMHO it is a bad idea to make LVM default, because there are too many cases around where people would not want LVM. LVM as an option is a far better solution and let the user decide what he wants. -- wobo
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Le lundi 21 février 2011 à 22:48 +0200, Buchan Milne a écrit : > On Monday, 21 February 2011 14:19:23 Michael Scherer wrote: > > and the same goes for > > os x. > > I thought Mac OS X had ext2/ext3 read support? Not on my version ( or it didn't work out of the box ). -- Michael Scherer
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Monday, 21 February 2011 11:49:27 Thomas Lottmann wrote: > I am still not convinced of how easy this can be. For having attempted > to manage (and learn) how to manage LVM partitons with CentOS, it is > quite complicated. So it certainly has many advantages, but I'm awaiting > an intuitive disk manager like Diskdrake to manage this stuff without > the need of preliminary knowledge. Yes, with diskdrake, it's no problem. Anaconda's LVM interface is quite confusing and complex. After installation, AFAIK, you can't access the same interface. system-config-lvm (if it's still around) was also pretty unusable. But, we have diskdrake, so why are the problems of CentOS an issue? Regards, Buchan
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Monday, 21 February 2011 14:19:23 Michael Scherer wrote: > Le lundi 21 février 2011 à 10:56 +0100, Wolfgang Bornath a écrit : > > Another part of the discussion may be the fact that a large number of > > users are running dual (or multiple) boot systems, keeping the > > pre-installed Windows and adding Linux. Others will have Windows and > > Mandriva, adding Mageia. > > > > While LVM may be nice if you are running one OS on one harddisk, it > > may be not so easy when running 3 OS on one harddisk. Or different > > installations of the same Linux (like stable version and cauldron). IMHO, it is *easier* to run multiple distributions on one machine with LVM, as you don't have the problem of having to statically pre-assign partitions to different distributions, and then have to image one filesystem to enlarge the filesystem before it, shrink the one after it, and put it back ... The only complication is where to put bootloaders, multiple distros sharing /boot is not great, so I just make a few small boot partitions before my PVs. > I do run lvm on Fedora and mac os x without any trouble. Windows out-the-box > will > not support any linux file system more than lvm, There are third-party drivers/software for accessing ext2/ext3 partitions under Windows, even LUKS+ext2/ext3. But, on LVM, I don't think there are any options. > and the same goes for > os x. I thought Mac OS X had ext2/ext3 read support? > For a linux system, a lvm logical volume is just another disk. That's a bit of an over-simplification. Hot-plugged LVM systems (I have a 2*2TB external disk enclosure, running in "SAFE50" mode, AKA half RAID0, half RAID1, RAID1 is a PV in a separate VG) don't auto-mount like hot-plugged non- LVM disks, rescue still have problems activating VGs until recently (may still be present), kernel upgrades may still mess up root= parameter on LVM etc. etc. I have been using LVM with online resizing in diskdrake since about Mandrake 8.2 (with XFS), and I think for users without non-Linux installations, it should be made more prominent or the default ... but only when all the remaining issues are addressed. Regards, Buchan
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Monday, 21 February 2011 18:56:22 Jeff Robins wrote: > > Michael Scherer wrote: > > > For a linux system, a lvm logical volume is just another disk. > > I've had issues in the past because Linux considered LVM just one logical > disk and I think the average user would eventually have the same problem as > well. I think moving to LVM as the default will create too many complaints > and support requests in the end. > > A long time ago I had a system with 6 SCSI disks, each 1.2GB. The system > was fairly useless with the single disks, but using LVM I had 1 disk of > reasonable size. I ran the system for about a year with no problems, but > then 1 of the disks failed. Normally this would be a medium inconvenience, > because I would just have to restore the files from that one drive to > another drive. However, with the LVM, ... or RAID0 ... > I lost the ability to read the entire > LVM. VG. > I had to restore the entire system, which was a much bigger pain. I > also could not obtain a disk of the same small size for a reasonable price, > which I was told would make the problem even bigger. Irrelevant for LVM. Only partly relevant for RAID0. > If I had used some redundancy, then I might have been able to restore the > one disk, but I was a novice user and didn't understand the need. I think > that most users who use the defaults and probably novice users, or at least > will be after Mageia takes off. I think LVM support is a must, but I think > making it the default, without also making some redundancy the default, > will cause more problems than it solves. For single-disk systems, there is no difference. For multi-disk systems, whether it would have been any different depends on whether you had a single VG or multiple VGs. But, by the time you talk about 6 disks, we're not talking about a default anymore. Regards, Buchan
Re: [Mageia-dev] time to switch from raw partitions to lvm?
> I think moving to LVM as the default will create too many complaints and > support requests in the end. I found it an annoyance in Fedora as a regular user. -- Hoyt
Re: [Mageia-dev] time to switch from raw partitions to lvm?
> Michael Scherer wrote: > > > > For a linux system, a lvm logical volume is just another disk. > > > I've had issues in the past because Linux considered LVM just one logical disk and I think the average user would eventually have the same problem as well. I think moving to LVM as the default will create too many complaints and support requests in the end. A long time ago I had a system with 6 SCSI disks, each 1.2GB. The system was fairly useless with the single disks, but using LVM I had 1 disk of reasonable size. I ran the system for about a year with no problems, but then 1 of the disks failed. Normally this would be a medium inconvenience, because I would just have to restore the files from that one drive to another drive. However, with the LVM, I lost the ability to read the entire LVM. I had to restore the entire system, which was a much bigger pain. I also could not obtain a disk of the same small size for a reasonable price, which I was told would make the problem even bigger. If I had used some redundancy, then I might have been able to restore the one disk, but I was a novice user and didn't understand the need. I think that most users who use the defaults and probably novice users, or at least will be after Mageia takes off. I think LVM support is a must, but I think making it the default, without also making some redundancy the default, will cause more problems than it solves. --Jeff
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Michael Scherer wrote: > > For a linux system, a lvm logical volume is just another disk. > > Perhaps a bit OT, but does the current harddisk install support cauldron trees on LVM ?
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Monday 21 February 2011, Maarten Vanraes wrote: > I think we ALL agree on LVM being present in diskdrake during installation. > > However, alot of things can go wrong if a user fiddles with those, so i > would keep it hidden under expert mode (not by default). Agreed. Being there, and being supported for machines that already have LVM on them is a must (eg. like installing Mageia at misc's hard disk). -- Say NO to spam and viruses. Stop using Microsoft Windows!
Re: [Mageia-dev] time to switch from raw partitions to lvm?
lunedì 21 febbraio 2011 alle 12:41, Maarten Vanraes ha scritto: > I think we ALL agree on LVM being present in diskdrake during installation. As far as i know is in (at least in Mandriva). I, for install, installed a 2009.1 with LVM in a system in which i had only 2 4Gb disks. Angelo signature.asc Description: This is a digitally signed message part.
Re: [Mageia-dev] time to switch from raw partitions to lvm?
lunedì 21 febbraio 2011 alle 10:36, Thierry Vignaud ha scritto: > Those who don't want LVM could still do manual partitionning. ... and viceversa... those who know what they're doing could choose LVM Angelo signature.asc Description: This is a digitally signed message part.
Re: [Mageia-dev] time to switch from raw partitions to lvm?
2011/2/21 Michael Scherer : > Le lundi 21 février 2011 à 10:56 +0100, Wolfgang Bornath a écrit : >> Another part of the discussion may be the fact that a large number of >> users are running dual (or multiple) boot systems, keeping the >> pre-installed Windows and adding Linux. Others will have Windows and >> Mandriva, adding Mageia. >> >> While LVM may be nice if you are running one OS on one harddisk, it >> may be not so easy when running 3 OS on one harddisk. Or different >> installations of the same Linux (like stable version and cauldron). > > I do run lvm on Fedora and mac os x without any trouble. Windows will > not support any linux file system more than lvm, and the same goes for > os x. > > For a linux system, a lvm logical volume is just another disk. Apart from all possible issues, diskdrake needs first to be improved. Looking on partitions when you run LVM still needs to have knowledge about how it works. And I really don't think people can easily understand PV, VG, LV and FS > -- > Michael Scherer > > -- Anne http://www.mageia.org
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Le lundi 21 février 2011 à 10:56 +0100, Wolfgang Bornath a écrit : > Another part of the discussion may be the fact that a large number of > users are running dual (or multiple) boot systems, keeping the > pre-installed Windows and adding Linux. Others will have Windows and > Mandriva, adding Mageia. > > While LVM may be nice if you are running one OS on one harddisk, it > may be not so easy when running 3 OS on one harddisk. Or different > installations of the same Linux (like stable version and cauldron). I do run lvm on Fedora and mac os x without any trouble. Windows will not support any linux file system more than lvm, and the same goes for os x. For a linux system, a lvm logical volume is just another disk. -- Michael Scherer
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Op maandag 21 februari 2011 10:56:23 schreef Wolfgang Bornath: > Another part of the discussion may be the fact that a large number of > users are running dual (or multiple) boot systems, keeping the > pre-installed Windows and adding Linux. Others will have Windows and > Mandriva, adding Mageia. > > While LVM may be nice if you are running one OS on one harddisk, it > may be not so easy when running 3 OS on one harddisk. Or different > installations of the same Linux (like stable version and cauldron). I think we ALL agree on LVM being present in diskdrake during installation. However, alot of things can go wrong if a user fiddles with those, so i would keep it hidden under expert mode (not by default). just my opinion
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Another part of the discussion may be the fact that a large number of users are running dual (or multiple) boot systems, keeping the pre-installed Windows and adding Linux. Others will have Windows and Mandriva, adding Mageia. While LVM may be nice if you are running one OS on one harddisk, it may be not so easy when running 3 OS on one harddisk. Or different installations of the same Linux (like stable version and cauldron). -- wobo
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Op maandag 21 februari 2011 10:36:15 schreef Thierry Vignaud: > On 21 February 2011 08:51, P. Christeas wrote: > >> What do you think about switching from defaulting to installing on raw > >> partitions to lvm > >> installing on LVs like fedora does ? > > > > I vote against that. (=to be enabled by default) > > > > LVM is fine for "enterprise" setups, or better, installations where the > > (expert) admin will need to resize/move partitions in the future. But, > > for simple machines/users, the complexity of having LVM is IMHO not > > worth it. > > > > (remember also that on all *nix OSes, you can just add a partition, move > > some files like /usr/share/doc into it and then mount it on > > /usr/share/doc, thus freeing /usr of some space. No LVM, no > > virtualization, no ZFS required) > > It's not as easy as LVM (need to use a partitionner). > Diskdrake and the like will force you to umount the partitions to resize > which may needs to boot on a rescue CD (eg for resizing / fs) > It may not be possible ie: > > - you already have 4 primary partitions and none of them is an extended > one. > > - If you've a small 8Go partition at start of the disk followed by one > To partition > and you want to increase the first one, you're screwed without LVM > With LVM, you can just got some free space from anywhere (even another > disk) > > What's more, one gains many features: > > - snapshots (yes snapshots for sql db backups are not for end users) but > still usefull for saving the whole system at one fixed time > > - you can extend some filesystems from space from other disks > > - it's easier to add space where needed when defaults partitions sizing > proved to be altered after some usage > > - one can live resize (w/o umouting/remounting) > > - one can use snapshots in order to rollback dangerous update > (eg: for trying initscript -> systemd switch, ...) > > I think it brings many usefull features. > Those who don't want LVM could still do manual partitionning. if we switch from ext4 to btrfs next year or so, we will have snapshotting and a lot of other usefull features.
Re: [Mageia-dev] time to switch from raw partitions to lvm?
Le 21/02/2011 10:36, Thierry Vignaud a écrit : On 21 February 2011 08:51, P. Christeas wrote: What do you think about switching from defaulting to installing on raw partitions to lvm installing on LVs like fedora does ? I vote against that. (=to be enabled by default) LVM is fine for "enterprise" setups, or better, installations where the (expert) admin will need to resize/move partitions in the future. But, for simple machines/users, the complexity of having LVM is IMHO not worth it. (remember also that on all *nix OSes, you can just add a partition, move some files like /usr/share/doc into it and then mount it on /usr/share/doc, thus freeing /usr of some space. No LVM, no virtualization, no ZFS required) It's not as easy as LVM (need to use a partitionner). Diskdrake and the like will force you to umount the partitions to resize which may needs to boot on a rescue CD (eg for resizing / fs) It may not be possible ie: - you already have 4 primary partitions and none of them is an extended one. - If you've a small 8Go partition at start of the disk followed by one To partition and you want to increase the first one, you're screwed without LVM With LVM, you can just got some free space from anywhere (even another disk) What's more, one gains many features: - snapshots (yes snapshots for sql db backups are not for end users) but still usefull for saving the whole system at one fixed time - you can extend some filesystems from space from other disks - it's easier to add space where needed when defaults partitions sizing proved to be altered after some usage - one can live resize (w/o umouting/remounting) - one can use snapshots in order to rollback dangerous update (eg: for trying initscript -> systemd switch, ...) I think it brings many usefull features. Those who don't want LVM could still do manual partitionning. I am still not convinced of how easy this can be. For having attempted to manage (and learn) how to manage LVM partitons with CentOS, it is quite complicated. So it certainly has many advantages, but I'm awaiting an intuitive disk manager like Diskdrake to manage this stuff without the need of preliminary knowledge.
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On 21 February 2011 08:51, P. Christeas wrote: >> What do you think about switching from defaulting to installing on raw >> partitions to lvm >> installing on LVs like fedora does ? > > I vote against that. (=to be enabled by default) > > LVM is fine for "enterprise" setups, or better, installations where the > (expert) admin will need to resize/move partitions in the future. But, for > simple machines/users, the complexity of having LVM is IMHO not worth it. > > (remember also that on all *nix OSes, you can just add a partition, move some > files like /usr/share/doc into it and then mount it on /usr/share/doc, thus > freeing /usr of some space. No LVM, no virtualization, no ZFS required) It's not as easy as LVM (need to use a partitionner). Diskdrake and the like will force you to umount the partitions to resize which may needs to boot on a rescue CD (eg for resizing / fs) It may not be possible ie: - you already have 4 primary partitions and none of them is an extended one. - If you've a small 8Go partition at start of the disk followed by one To partition and you want to increase the first one, you're screwed without LVM With LVM, you can just got some free space from anywhere (even another disk) What's more, one gains many features: - snapshots (yes snapshots for sql db backups are not for end users) but still usefull for saving the whole system at one fixed time - you can extend some filesystems from space from other disks - it's easier to add space where needed when defaults partitions sizing proved to be altered after some usage - one can live resize (w/o umouting/remounting) - one can use snapshots in order to rollback dangerous update (eg: for trying initscript -> systemd switch, ...) I think it brings many usefull features. Those who don't want LVM could still do manual partitionning.
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Mon, 21 Feb 2011 09:51:31 +0200, P. Christeas wrote: On Sunday 20 February 2011, Thierry Vignaud wrote: Hi What do you think about switching from defaulting to installing on raw partitions to lvm installing on LVs like fedora does ? I vote against that. (=to be enabled by default) LVM is fine for "enterprise" setups, or better, installations where the (expert) admin will need to resize/move partitions in the future. But, for simple machines/users, the complexity of having LVM is IMHO not worth it. We often see people coming at the lug who have issue of having "not enough space on their home", and who want to resize their partition. Of course, they work around by using various adhoc system ( like mounting external disk and so on ), but I think it would be much nicer for them to be able to resize it easily ( and not by using a livecd ). (remember also that on all *nix OSes, you can just add a partition, move some files like /usr/share/doc into it and then mount it on /usr/share/doc, thus freeing /usr of some space. No LVM, no virtualization, no ZFS required) This seems to me quite complex, when compared to a graphical interface to resize a disk ( as would diskdrake or palimsest be ). And of course, that's also something that was tried at Mandriva, with the unfortunate problem of "svn full" and "mirror full" problem from some years ago. I am not sure that allowing this kind of hack to perpetuate "because it worked on my computer so it would work on my server" is a so good idea. ( on the other hand, if people do unclean stuff, I will have less effort to keep my job or to take their ) -- Michael Scherer
Re: [Mageia-dev] time to switch from raw partitions to lvm?
* P. Christeas (p_chr...@hol.gr) wrote: > On Sunday 20 February 2011, Thierry Vignaud wrote: > > Hi > > > > What do you think about switching from defaulting to installing on raw > > partitions to lvm > > installing on LVs like fedora does ? > > I vote against that. (=to be enabled by default) > > LVM is fine for "enterprise" setups, or better, installations where the > (expert) admin will need to resize/move partitions in the future. But, for > simple machines/users, the complexity of having LVM is IMHO not worth it. > > (remember also that on all *nix OSes, you can just add a partition, move some > files like /usr/share/doc into it and then mount it on /usr/share/doc, thus > freeing /usr of some space. No LVM, no virtualization, no ZFS required) I mostly agree, but the snapshot feature can really be an advantage... -- Olivier Thauvin CNRS - LATMOS ♖ ♘ ♗ ♕ ♔ ♗ ♘ ♖ pgpAdB76wOGXc.pgp Description: PGP signature
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Sunday 20 February 2011, Thierry Vignaud wrote: > Hi > > What do you think about switching from defaulting to installing on raw > partitions to lvm > installing on LVs like fedora does ? I vote against that. (=to be enabled by default) LVM is fine for "enterprise" setups, or better, installations where the (expert) admin will need to resize/move partitions in the future. But, for simple machines/users, the complexity of having LVM is IMHO not worth it. (remember also that on all *nix OSes, you can just add a partition, move some files like /usr/share/doc into it and then mount it on /usr/share/doc, thus freeing /usr of some space. No LVM, no virtualization, no ZFS required) -- Say NO to spam and viruses. Stop using Microsoft Windows!
Re: [Mageia-dev] time to switch from raw partitions to lvm?
On Sunday, 20 February 2011 17:51:27 Thierry Vignaud wrote: > Hi > > What do you think about switching from defaulting to installing on raw > partitions to lvm > installing on LVs like fedora does ? > > It does help brings more flexibility. Sure, but it can still introduce boot problems after kernel upgrade. The bug about kernel commandline containing 'root=/dev/' seems to still occur (at least on Mandriva 2010.x). However, it would be nice to have it, leaving some space on the VG, and possibly have urpmi prompt to extend filesystems if it is required for software installation/upgrade. Regards, Buchan
Re: [Mageia-dev] time to switch from raw partitions to lvm?
> What do you think about switching from defaulting to installing on raw > partitions to lvm Personally i don't like lvm i prefer installing it when needed. iirc it's not easy to mount lvm partiotions when a dd images has been performed, but i maybe wrong... > installing on LVs like fedora does ? i often disable it :) > It does help brings more flexibility. The same as deciding to install it knowing what you're doing, but that's my opinion of course :) Cheers, -- Angelo signature.asc Description: This is a digitally signed message part.
[Mageia-dev] time to switch from raw partitions to lvm?
Hi What do you think about switching from defaulting to installing on raw partitions to lvm installing on LVs like fedora does ? It does help brings more flexibility. See you
