[linux-lvm] ubuntu xenial + lvmlockd

[Charles Koprowski]

Hi all,

I'm trying to set up a shared VG between 2 ubuntu servers (xenial) using
lvmlockd for locking.

Unfortunately, even if the default config (lvm.conf) mentions the
possibillity to use lvmlockd (use_lvmlockd = 1), I cannot find any trace of
the daemon lvmlockd or lvmlockctl tool in ubuntu.

Does anyone already done this before ?

Do I have to build lvm from source in order to use lvmlockd ?

Thanks

Regards,

Charles

[David Teigland]

Post by Charles Koprowski
Hi all,
I'm trying to set up a shared VG between 2 ubuntu servers (xenial) using
lvmlockd for locking.
Unfortunately, even if the default config (lvm.conf) mentions the
possibillity to use lvmlockd (use_lvmlockd = 1), I cannot find any trace of
the daemon lvmlockd or lvmlockctl tool in ubuntu.
Does anyone already done this before ?
Do I have to build lvm from source in order to use lvmlockd ?

I'd guess that lvm was not built with lvmlockd support, in which case you
would need to rebuild it with one or both of --enable-lockd-sanlock,
--enable-lockd-dlm (and I'm going to rename those options to be "lvmlockd"
in a minute.)

Dave

[Charles Koprowski]

Post by David Teigland

Post by Charles Koprowski
Hi all,
I'm trying to set up a shared VG between 2 ubuntu servers (xenial) using
lvmlockd for locking.
Unfortunately, even if the default config (lvm.conf) mentions the
possibillity to use lvmlockd (use_lvmlockd = 1), I cannot find any trace

of

Post by Charles Koprowski
the daemon lvmlockd or lvmlockctl tool in ubuntu.
Does anyone already done this before ?
Do I have to build lvm from source in order to use lvmlockd ?

I'd guess that lvm was not built with lvmlockd support, in which case you
would need to rebuild it with one or both of --enable-lockd-sanlock,
--enable-lockd-dlm (and I'm going to rename those options to be "lvmlockd"
in a minute.)

Thank you David !

Would you consider the use of lvmlockd + sanlock as "production ready" ?

My goal here is to replace an existing cluster of 5 nodes using clvmd + dlm
+ corosync to access a shared VG of 6 TB containing around 300 LVs.

The current solution is working fine but I find using dlm + corosync "just"
for locking a bit overkill.

Regards,

Charles

[David Teigland]

Post by Charles Koprowski
Would you consider the use of lvmlockd + sanlock as "production ready" ?

I believe it will work better than clvmd. There is one main thing, unique
to using sanlock, that you should verify in your environment.
lvmlockd+sanlock is sensitive to spikes in i/o delays. If sanlock sees
several consecutive large i/o delays (> 10 sec each), e.g. during heavy
use from applications, or during path switching, this can trigger spurious
failure detection. (This is analogous to network delays when using
network-based solutions.)

(We can increase i/o timeouts to compensate if really necessary.)

Post by Charles Koprowski
My goal here is to replace an existing cluster of 5 nodes using clvmd + dlm
+ corosync to access a shared VG of 6 TB containing around 300 LVs.
The current solution is working fine but I find using dlm + corosync "just"
for locking a bit overkill.

I agree.

Dave