[linux-lvm] lvcreate goes into deep-sleep while creating an xfs snapshot

[Klaus Strebel]

Sven Riedel schrieb:
> Hi,
> I'm creating a backup script for a database using lvm snapshots.
> The script ran fine for a few test runs, then I added xfs_freeze -f 
> just before the lvcreate command, as per HOWTO recipe. Now
> lvcreate went into deep-sleep and wont wake up:
> 
> update:~/bin# ps ax | grep lvcreate
> 25053 pts/2    D<L+   0:00 lvcreate -s -L 55M -n tables_snap 
>    /dev/database_vg/tables_lv
> 
> Running lvdisplay in a different terminal to see if lvm itself
> is still seeing all LVs results in lvdisplay going into 
> deep-sleep mode as well. Doing an strace -p 25053 
> doesn't display anything (strace won't catch my interrupts
> either, but according to ps it's in a regular sleep).
> 
> dmesg doesn't say anything to this situation.
> 
> Is there a known issue with snapshots and xfs_freeze? 
> Any way I can gather pertinent debugging info?
> 
> I'm running lvm 2.01.04 (package from debian unstable).

The HOWTO is way old, with LVM2 the XFS filesystem is 'frozen' 
automaticly on the mount -onouuid,ro ( not quite sure, but probably also 
for LVM1 ..., think it's in the XFS code ).
So, forget xfs_freeze. It's freezing your box, not your filesystems.

XFS-Guys: shouldn't xfs_freeze be removed from xfs_cmds? It's doing more 
harm than use ( if any use at all ), so ...
-- 
Mit freundlichen Grüssen / best regards

Klaus Strebel, Dipl.-Inform. (FH), mailto:klaus.strebel at gmx.net

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