Disk partition required for LVM?
We have been experiencing strange LVM behaviour on multiple machines. The situation:
- Debian 3.1 (Sarge)
- 2.6.8.1 Kernel
- LVM2
- 3 IDE disks (2x80GB, 1x120GB) (All Maxtors)
Creating physical volumes is no problem for two disks, but with the third disk (it is actually on hdb and already a different disk then the one originally used) problems begin. pvcreate does not give any errors, but with pvdisplay the disk is not shown while pvscan gives "Couldn't find device with uuid 'xAMOJ3-xIGd-AJQK-HN5Q-Q9Yg-Mu2D-UYxn0Y'"
It is possible to create volume groups and logical volumes, but pvscan, vgscan and lvscan keeping failing with the above error.
Neither of the 3 disks has a partition when starting. When on hdb a partition is created and then hdb1 is used as physical volume everything works fine.
Why does the partition need to be created on that disk for LVM to work (and not on the other two)? Is this a problem with LVM2, the 2.6 kernel? Or could it be hardware not functioning as it should, e.g. disk or controller?
I would like to know why the creation of a partition is necessary. Has anyone experienced the same problem/behaviour with LVM? If so, is there a solution so no partition is needed?
Thanks in advance for the help.
Quoted 10 lines · On Tue, Sep 21, 2004 at 02:32:06PM +0200, [email protected] wrote:
Why does the partition need to be created on that disk for LVM to work (and not on the other two)? Is this a problem with LVM2, the 2.6 kernel? Or could it be hardware not functioning as it should, e.g. disk or controller?
I would like to know why the creation of a partition is necessary. Has anyone experienced the same problem/behaviour with LVM? If so, is there a solution so no partition is needed?
Check that you don't have a symlink from /dev/hdb to /dev/cdrom. The debian lvm.conf file excludes /dev/cdrom from LVM searches.
Signature · 1 line
patrick
Quoted 2 lines · Patrick Caulfield
Check that you don't have a symlink from
/dev/hdbto/dev/cdrom. The debian lvm.conf file excludes/dev/cdromfrom LVM searches.
It was indeed the symlink, although not from hdb to cdrom, but from cdrom to hdb. Removing this symlink (or commenting out the filter option in lvm.conf) solved the problem.
CDRom has only been present for installation, and afterwards swapped for extra disk. Symlink however isn't updated.
Another remark: although cdrom are filtered (and thus not allowed for LVM), no warning/error messages appear. Wouldn't it be useful if LVM checks this and shows warning/error messages or even exits during creation?
Quoted 8 lines · On Tue, 2004-09-21 at 09:30, [email protected] wrote:
Quoted 2 lines · Patrick Caulfield
Check that you don't have a symlink from
/dev/hdbto/dev/cdrom. The debian lvm.conf file excludes/dev/cdromfrom LVM searches.It was indeed the symlink, although not from hdb to cdrom, but from cdrom to hdb. Removing this symlink (or commenting out the filter option in lvm.conf) solved the problem.
Quoted 7 lines
CDRom has only been present for installation, and afterwards swapped for extra disk. Symlink however isn't updated.
Another remark: although cdrom are filtered (and thus not allowed for LVM), no warning/error messages appear. Wouldn't it be useful if LVM checks this and shows warning/error messages or even exits during creation?
Not really. Consider users who use multipath; they have to filter or they'll see the same PV over and over and over again. A reference in the docs *would* help, as would a debug message in syslog (debug so it only shows if we're looking for problems).
Signature · 2 lines
David Johnston <[email protected]> Little Bald Consulting, LLC