[linux-lvm] Shared LUN without CLM

[linux-lvm] Shared LUN without CLM

[Руденко Александр]

Hi, friends.

I have strange question)

I have one shared LUN on many different hosts.
LUN is PV in some VG.

Each hosts can make any operation in this VG - create LV, remove LV, resize LV, etc.
If i want access to same LV on same host, i take "lvscan" and "lvchange -aey /dev/VG/LV_name".
I'm sure can't two modification VG in same time.

It work fine for me.

My question.

Can i not use the CLVM extension?

CLVM is great extension for LVM, but i will have more 100 nodes.
This count not supported in corosync.

Sorry for my english)

Re: [linux-lvm] Shared LUN without CLM

[Zdenek Kabelac]

Dne 20.9.2016 v 18:07 Руденко Александр napsal(a):
> Hi, friends.
>
> I have strange question)
>
> I have one shared LUN on many different hosts.
> LUN is PV in some VG.
>
> Each hosts can make any operation in this VG - create LV, remove LV, resize LV, etc.
> If i want access to same LV on same host, i take "lvscan" and "lvchange -aey /dev/VG/LV_name".
> I'm sure can't two modification VG in same time.
>
> It work fine for me.
>
> My question.
>
> Can i not use the CLVM extension?
>
> CLVM is great extension for LVM, but i will have more 100 nodes.
> This count not supported in corosync.
>


There is now (slowly) introduce another clustered locking support where
the instead of 'dlm' locking engine it's using  'sanlock'

It's targeting the 'many-nodes' clusters, might be likely worth to check.

It has some advantages over clvmd/dlm and on the other hand some features are 
missing (i.e. remove node activation).

But from the context you've show - it seems like it might be a good fit to 
start playing with..

Regards

Zdenek

Re: [linux-lvm] Shared LUN without CLM

[David Teigland]

On Wed, Sep 21, 2016 at 01:46:12PM +0200, Zdenek Kabelac wrote:
> Dne 20.9.2016 v 18:07 Руденко Александр napsal(a):
> >Hi, friends.
> >
> >I have strange question)
> >
> >I have one shared LUN on many different hosts.
> >LUN is PV in some VG.
> >
> >Each hosts can make any operation in this VG - create LV, remove LV, resize LV, etc.
> >If i want access to same LV on same host, i take "lvscan" and "lvchange -aey /dev/VG/LV_name".
> >I'm sure can't two modification VG in same time.
> >
> >It work fine for me.
> >
> >My question.
> >
> >Can i not use the CLVM extension?
> >
> >CLVM is great extension for LVM, but i will have more 100 nodes.
> >This count not supported in corosync.
> 
> 
> There is now (slowly) introduce another clustered locking support where
> the instead of 'dlm' locking engine it's using  'sanlock'
> 
> It's targeting the 'many-nodes' clusters, might be likely worth to check.
> 
> It has some advantages over clvmd/dlm and on the other hand some
> features are missing (i.e. remove node activation).
> 
> But from the context you've show - it seems like it might be a good
> fit to start playing with..

See here for more information:
http://man7.org/linux/man-pages/man8/lvmlockd.8.html