Re: ext2resize
On Wed, 29 Mar 2000, Seth Vidal wrote:
hi folks,
ext2resize claims to be able resize ext2 partitions w/o destroying data.
While there is evidence of this on normal drives and hw raid drives too.
I'd like to know if it will work on sw raid drives.
anyone know?
The filesystem resides on a block-device, and that's what the filesystem
resizer knows about. Whether the block-device is MD, single disk, loopback-
mounted file on another fs, or whatever, doesn't matter.
What does matter to the resizer however is, that your block device has
actually changed it's size. If you resize a block-device (partition or
array) the resizer can then expand the filesystem to span the entire
device. But the resizer cannot magically guess how you would have expanded
some block device by itself. The resizer simply _requires_ that the
block device is already resized.
However, with RAID you can resize linear devices (by putting in another
disk and mkraid'ing the array with the updated raidtab - causes no loss
of data if done right) and RAID-0 devices (using my raid reconfiguration
utility - found on http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/).
You cannot resize RAID-5 arrays (yet).
If resizing block-devices is somthing you do a lot, you might want to
consider using LVM instead of RAID. It's more flexible. But from what
I can understand LVM does not provide redundancy. If RAID-5 capability
was added to the RAID reconfiguration tool, this would be a real win.
Oh btw. I resized a 60G RAID-0 into 100+G using my reconfiguration tool
and the ext2 resizer. Works like a charm - as it should.
--
: [EMAIL PROTECTED] : And I see the elder races, :
:.: putrid forms of man:
: Jakob Østergaard : See him rise and claim the earth, :
:OZ9ABN : his downfall is at hand. :
:.:{Konkhra}...:
Re: ext2resize
On Wed, Mar 29, 2000 at 03:40:42PM -0800, Peter Andersen wrote: I was looking at LVM and wondering what advantage it would give me. I like the idea of the volume groups and logical volumes but what does LVM give me other than the ability to resize/change volumes? LVM snapshot is a nice feature, you create a snapshot at one point in time then lvm will only write changes to the snapshot device, this enables you to make consistent backups. L. -- Luca Berra -- [EMAIL PROTECTED] Communication Media Services S.r.l.
RE: ext2resize
-Original Message- From: Seth Vidal [mailto:[EMAIL PROTECTED]] Sent: Wednesday, March 29, 2000 11:33 AM To: [EMAIL PROTECTED] Subject: ext2resize hi folks, ext2resize claims to be able resize ext2 partitions w/o destroying data. While there is evidence of this on normal drives and hw raid drives too. I'd like to know if it will work on sw raid drives. Seems to me that this would only work if you were using it with the Logical Volume Manager (is that what it's called?). I think that the RAID devices are treated as a partition, not as a whole disk, so it wouldn't work that way. I don't know enough about LVM to know if that would work either. Greg
Re: ext2resize
I would 'hope' it would work. (under the assumption that raid is only concerned with portraying a block device without concern for what is stored on that block device) Of course, that's just a 'hope'. :) On Wed, 29 Mar 2000, Seth Vidal wrote: -hi folks, - ext2resize claims to be able resize ext2 partitions w/o destroying data. -While there is evidence of this on normal drives and hw raid drives too. -I'd like to know if it will work on sw raid drives. - -anyone know? - -thanks - --sv - -
Re: ext2resize
ext2resize claims to be able resize ext2 partitions w/o destroying data. What's more, it does ... While there is evidence of this on normal drives and hw raid drives too. (I assume the `While' is spurious). I have first hand evidence of the first. I'd like to know if it will work on sw raid drives. It's independent of the underlying hardware -- ext2 just sees a set of disk blocks -- it does not care what type they are! (actually, it's best to use it on top of LVM) anyone know? I have used it on SW RAID.
Re: ext2resize
What's more, it does ... While there is evidence of this on normal drives and hw raid drives too. (I assume the `While' is spurious). I have first hand evidence of the first. I'd like to know if it will work on sw raid drives. It's independent of the underlying hardware -- ext2 just sees a set of disk blocks -- it does not care what type they are! (actually, it's best to use it on top of LVM) anyone know? I have used it on SW RAID. Just felt like I should ask first - it makes me uneasy expanding the drive - how would you go about doing this with sw raid - like how would I do it if I wanted to add a drive to the array? this might be useful to add to the howto. -sv
Re: ext2resize
On Wed, Mar 29, 2000 at 03:49:17PM -0500, David Holl wrote: I would 'hope' it would work. (under the assumption that raid is only concerned with portraying a block device without concern for what is stored on that block device) Of course, that's just a 'hope'. :) Unfortunately, with the RAID superblock at the back of each RAID partition, you're going to need a tool that understands that it's there. I remember seeing someone posting about a RAID resizer which calls the resize2fs package. Don't know where that went, but that's probably what you want. -- Randomly Generated Tagline: "... by changing many lightbulbs, and I'm an Electrical Engineer, and it only takes 1 of us ..." - Prof. Vaz
Re: ext2resize
What you *REALLY* want is LVM url please? pointers of some type? -sv
Re: ext2resize
What you *REALLY* want is LVM url please? Sorry -- I assumed RAID users would all know about http://linux.msede.com/lvm/ Mirror sites The following ftp sites are known to mirror the LVM tree: ftp://ftp.gwdg.de/pub/linux/misc/lvm/ (daily mirror, thanks to Eberhard Moenkeberg) ftp://source.rfc822.org/pub/mirror/LVM/ (daily mirror, thanks to Richard Higson) ftp://linux.mathematik.tu-darmstadt.de/pub/linux/mirrors/misc/lvm/ (daily mirror, thanks to Holger Grothe) ftp://ftp2.sinica.edu.tw/pub1/lvm (Taiwan)
Re: ext2resize
What you *REALLY* want is LVM On the subject of LVM... I'm getting ready to setup a storage server for raw video using 3ware (www.3ware.com) IDE HW raid and 6 40gig ide drives. Speed isn't as much as issue as raw volume of storage. I was looking at LVM and wondering what advantage it would give me. I like the idea of the volume groups and logical volumes but what does LVM give me other than the ability to resize/change volumes?
Re: ext2resize
I would think that a block device is a block device from the point of view of software like this, so I cannot see any reason to expect a block device created by software RAID to look any different to it. That said, I have never tried it, so take my advice with a grain of salt. -- Mike On Wed, 29 Mar 2000, Seth Vidal wrote: hi folks, ext2resize claims to be able resize ext2 partitions w/o destroying data. While there is evidence of this on normal drives and hw raid drives too. I'd like to know if it will work on sw raid drives. anyone know? thanks
Re: ext2resize
On the subject of LVM... I'm getting ready to setup a storage server for raw video using 3ware (www.3ware.com) IDE HW raid and 6 40gig ide drives. Speed isn't as much as issue as raw volume of storage. I was looking at LVM and wondering what advantage it would give me. I like the idea of the volume groups and logical volumes but what does LVM give me other than the ability to resize/change volumes? LVM is very nice if you need more than 1 partition on your RAID storage. YOu then just create one large RAID set, and partition it with LVM, its really very handy. Also LVM could even combine more one one physical storage into a Volume Group. Of course you could do that with RAID too, but with LVM you could do it after you´ve created you´re filesystems. E.g you buy today a 100 GB Raid for you´re videoservice, and next year add a second RAID set with for example 1 TB. LVM would allow you to combine both RAID sets into on Logical Volume. Of course this needs a working ext2resize. And of course I would not recommend such a large Logical Volume without an Journaling Filesystem. Sincerely, Klaus -- Klaus Steinberger Beschleunigerlabor der TU und LMU Muenchen Phone: (+49 89)289 14287Hochschulgelaende, D-85748 Garching, Germany FAX: (+49 89)289 14280EMail: [EMAIL PROTECTED] URL: http://www.bl.physik.tu-muenchen.de/~k2/ Stimm gegen Spam: http://www.politik-digital.de/spam/ In a world without fences and walls, who needs Windows and Gates?
