[linux-lvm] LVM startup takes too long

[linux-lvm] LVM startup takes too long

[Dan Bar Dov]

When I start up our system, I have a startup script that runs pvscan, vgscan
and lvscan, and parses their output.

This takes too long - with a small SAN - 1x6 disks FC jbod + 2 FC RAID
controllers, it takes roughly 45 seconds with pvscan and vgscan about 23
seconds each.

Its pretty obvious that with more storage it will take longer.

Any ideas how can I speed it up? 
(can I run vgscan/pvscan in parallel ?, can I get all the data I need from a
single scan ?)

Thanks
Dan

Re: [linux-lvm] LVM startup takes too long

[Magosányi Árpád]

Hi!

Maybe you have too much device inodes to check but otherwise
uninteresting? In this case it is not proportional to the
amount of your storage.

The solution to this is either filter what you scan, or if you
can, you can try to either rm unnecessary files from /dev,
or tell your *scan programs to look at a different directory,
and polupate it only with the needed devices. At the worst
case you can do it by editing the path in the source and recompile.

A levelez�m azt hiszi, hogy Dan Bar Dov a k�vetkez�eket �rta:
> When I start up our system, I have a startup script that runs pvscan, vgscan
> and lvscan, and parses their output.
> 
> This takes too long - with a small SAN - 1x6 disks FC jbod + 2 FC RAID
> controllers, it takes roughly 45 seconds with pvscan and vgscan about 23
> seconds each.
> 
> Its pretty obvious that with more storage it will take longer.
> 
> Any ideas how can I speed it up? 
> (can I run vgscan/pvscan in parallel ?, can I get all the data I need from a
> single scan ?)
> 
> Thanks
> Dan
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 

-- 
GNU GPL: csak tiszta forr�sb�l

[linux-lvm] snapshots with XFS and 2.6 kernel

[David Powers]

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I was attempting to implement a quick snapshot backup solution using 
lvm2, XFS, and snapshots on a 2.6 kernel.  After some very odd hangs I 
started hunting around in the lists and came across some posts that 
snapshots were not yet properly implemented in 2.6.  These were from a 
few months ago and a quick scan of the lvm2 tarball (in particular 
WHATS_NEW and README) doesn't seem to indicate that snaphots should be 
avoided.  So the question is, are snapshots usable?  And if they aren't 
where would I find more current information about when they will be?  as 
it stands now creating a snapshot tends to produce:

disk1 snapshots # lvcreate -L5G -nsnaptest -s /dev/filestore/archive
  device-mapper ioctl cmd 9 failed: Invalid argument
  Couldn't load device 'filestore-snaptest'.
  Problem reactivating origin archive

an lvscan afterwards shows the snapshot:

disk1 snapshots # lvscan
  ACTIVE   Original '/dev/filestore/archive' [60.00 GB] next free (default)
  ACTIVE            '/dev/filestore/groups' [50.00 GB] next free (default)
  ACTIVE            '/dev/filestore/personal' [50.00 GB] next free (default)
  ACTIVE   Snapshot '/dev/filestore/snaptest' [5.00 GB] next free (default)

but the device isn't actually created and it takes hard rebooting and a 
lot of fiddling and poking to delete it.  Any help or insight is 
appreciated.

-David

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