[Bug 54002] Re: [Bug 54002] Re: [Bug 54002] Re: LVM/MD root filesystem not found by uuid
On Mon, 2006-09-11 at 18:58 +, Dominik Kubla wrote: > Am Monday 11 September 2006 00:24 schrieb Matt Zimmerman: > > Reopening udev task, as md detection doesn't seem to be sorted yet. > > > > MD folks, please provide details. > > > > ** Changed in: udev (Ubuntu) > >Status: Fix Released => Confirmed > > We have two issues at hand: > > 1. Mounting by UUID does not work for MD in initramfs. I am trying to track > this one down (but I think this is a waste of time because there will always > be rather common scenarios where mounting by UUID will never work. But this > should be discussed elsewhere). I'll have to rig a serial terminal to capture > the console output and create a custom initramfs which will drop to a shell > right before it attempts to mount the root device so that I can do some > debugging. > break=mount on the kernel command-line. > 2. update-grub changes MD to mount by UUID even so it does not work at the > moment. This one is rather easy to fix: > I'd rather fix #1. and make mount-by-UUID work. Scott -- Scott James Remnant [EMAIL PROTECTED] -- LVM/MD root filesystem not found by uuid https://launchpad.net/bugs/54002 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 54002] Re: [Bug 54002] Re: [Bug 54002] Re: [Bug 54002] Re: LVM/MD root filesystem not found by uuid
On Sun, Sep 10, 2006 at 08:37:14PM -, Dominik Kubla wrote: > Am Sunday 10 September 2006 21:02 schrieb Matt Zimmerman: > > You're making assumptions about the behaviour of a 1000+-line program by > > reading one comment. > > No, I am not making assumptions. You stated that grub-update will not convert > LVM/devmapper entries anymore to avoid corruption of the system boot process. > I demonstrated that the system boot process is still corrupted for the rather > simple case of root disks being mirrored with MD. No, you didn't. You grepped for a string in the update-grub script and claimed that this was evidence that it "corrupted" the system. I can't agree there. This conversion is a necessary step in order to support future changes in the kernel which will change the naming and order in which storage devices are detected. This is not necessary for LVM or EVMS volumes. However, as far as I am aware, md devices are assigned in sequential order based on a device scan, which means that they are susceptible to breakage due to these ordering changes, and should be mounted by uuid rather than by explicit device path. If that isn't working correctly for you, then please help us to debug the problem. > > If you read the convert_kopt_to_uuid function referenced above, you'll see > > that it includes conditional code intended to exclude device-mapper (LVM) > > and EVMS devices from the conversion. > > I went through this file line by line and I can say I have a rather good > understanding what it attempts to do and what it does. > > You are the one making assumptions here: about how a system is configured. > That is something you can not know reliably. So following the principle of > least impact you should not change anything without explicit consent by the > system administrator requesting the task. In general, I would agree, but in this case, the conversion is necessary in order to avoid breakage in the future. You can read the background for this decision in https://launchpad.net/distros/ubuntu/+spec/probe-for-root-filesystem and https://launchpad.net/distros/ubuntu/+spec/libata-for-all-ata-disks If you have specific criticism of the decision, then please address it to the development mailing list at [EMAIL PROTECTED], and limit discussion in this bug report to the matter at hand. > > If you have problems with the conversion, a constructive bug report with > > details of your configuration would be appreciated. > > My problem is that you convert the file at all. I do not want this setting to > be converted, even if mounting by UUID would be working. I'm afraid this is unavoidable, as I've tried to explain above. > But as I understand now, the problem is not a technical one, so i will > simply dpkg-divert /sbin/update-grub and disable the conversion stuff in > my local copy and be done with it. This will not further the process of fixing the problem. I know of no reason why UUID mounting of md devices should not work, so your assistance in debugging the problem would be appreciated. -- - mdz -- LVM/MD root filesystem not found by uuid https://launchpad.net/bugs/54002 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 54002] Re: [Bug 54002] Re: [Bug 54002] Re: LVM/MD root filesystem not found by uuid
Am Sunday 10 September 2006 21:02 schrieb Matt Zimmerman: > On Sun, Sep 10, 2006 at 06:26:50PM -, Dominik Kubla wrote: > > # egrep -nC1 "Update.*root device.*UUID" /sbin/update-grub > > 751- > > 752:# Update the root device to mount-by-UUID > > 753-kopt=$(convert_kopt_to_uuid "$kopt") > > You're making assumptions about the behaviour of a 1000+-line program by > reading one comment. No, I am not making assumptions. You stated that grub-update will not convert LVM/devmapper entries anymore to avoid corruption of the system boot process. I demonstrated that the system boot process is still corrupted for the rather simple case of root disks being mirrored with MD. > If you read the convert_kopt_to_uuid function referenced above, you'll see > that it includes conditional code intended to exclude device-mapper (LVM) > and EVMS devices from the conversion. I went through this file line by line and I can say I have a rather good understanding what it attempts to do and what it does. You are the one making assumptions here: about how a system is configured. That is something you can not know reliably. So following the principle of least impact you should not change anything without explicit consent by the system administrator requesting the task. > If you have problems with the conversion, a constructive bug report with > details of your configuration would be appreciated. My problem is that you convert the file at all. I do not want this setting to be converted, even if mounting by UUID would be working. But as I understand now, the problem is not a technical one, so i will simply dpkg-divert /sbin/update-grub and disable the conversion stuff in my local copy and be done with it. Regards, Dominik -- Be at war with your vices, at peace with your neighbours, and let every new year find you a better man. (Benjamin Franklin, 1706-1790) -- LVM/MD root filesystem not found by uuid https://launchpad.net/bugs/54002 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
