[linux-lvm] lvmlockd: how to convert lock_type from sanlock to dlm?

[linux-lvm] lvmlockd: how to convert lock_type from sanlock to dlm?

[Eric Ren]

Hello David,

On my testing cluster,  the lvmlockd was firstly used with sanlock and 
everything was OK.
After some play, I want to change the "sanlock" lock_type of a VG into 
"dlm" locktype.

With dlm_controld running, I tried as following, but still failed.

1.  Performed as the "Changing dlm cluster name" section of `man lvmlockd`:

     # dlm_tool ls             // no lockspace available
     # vgs
        Reading VG vg1 without a lock.
       VG  #PV #LV #SN Attr   VSize  VFree
       vg1   1   1   0 wz--ns 19.97g 18.72g
     # vgchange --lock-type none --force vg1       // the cmd comes from 
`man lvmlockd`
   Command does not accept option: --force.

2. Tried with 'global/locking_type=0':

# vgchange --config 'global/locking_type=0' --lock-type dlm vg1
   WARNING: Locking disabled. Be careful! This could corrupt your metadata.
   ERROR: configuration setting use_lvmlockd cannot be used with 
clustered locking_type 3.

The error message is strange because the locking_type=0 in the command 
line and locking_type=1
in lvm.conf.

Not sure if it's a real problem or am doing something wrong?

Regards,
Eric

Re: [linux-lvm] lvmlockd: how to convert lock_type from sanlock to dlm?

[David Teigland]

On Mon, Nov 20, 2017 at 06:35:20PM +0800, Eric Ren wrote:
> On my testing cluster,� the lvmlockd was firstly used with sanlock and
> everything was OK.  After some play, I want to change the "sanlock"
> lock_type of a VG into "dlm" locktype.

> # vgchange --lock-type none --force vg1������ // the cmd comes from `man lvmlockd`
> Command does not accept option: --force.

First you'll need this recent fix:
https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=f611b68f3c02b9af2521d7ea61061af3709fe87c

--force was broken at some point, and the option is now --lockopt force.

To change between lock types, you are supposed to be able to change to a
local VG, then from local to the other lock type.  The man page sections:

  changing a lockd VG to a local VG
  changing a local VG to a lockd VG

But it looks like a fix is needed in those instructions.  I believe
"vgchange --lock-type none <vgname>" needs to include --lockopt force.
If you could verify this for me, I'll update the man page.
Thanks
Dave

Re: [linux-lvm] lvmlockd: how to convert lock_type from sanlock to dlm?

[Eric Ren]

David,

> First you'll need this recent fix:
> https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=f611b68f3c02b9af2521d7ea61061af3709fe87c
>
> --force was broken at some point, and the option is now --lockopt force.

Thanks!

> To change between lock types, you are supposed to be able to change to a
> local VG, then from local to the other lock type.  The man page sections:
>
>    changing a lockd VG to a local VG
>    changing a local VG to a lockd VG
>
> But it looks like a fix is needed in those instructions.  I believe
> "vgchange --lock-type none <vgname>" needs to include --lockopt force.
> If you could verify this for me, I'll update the man page.

It works! I did as the following:

"""
sle15-c1-n1:~ # vgs
   Reading VG vg1 without a lock.
   VG  #PV #LV #SN Attr   VSize  VFree
   vg1   1   1   0 wz--ns 19.97g 18.72g
sle15-c1-n1:~ # vgchange --lock-type none vg1
   Cannot access VG vg1 due to failed lock.
sle15-c1-n1:~ # vgchange --lock-type none --lockopt force vg1
Forcibly change VG lock type to none? [y/n]: y
   Volume group "vg1" successfully changed
sle15-c1-n1:~ # vgchange --lock-type dlm vg1
   Volume group "vg1" successfully changed
sle15-c1-n1:~ # vgs
   Reading VG vg1 without a lock.
   VG  #PV #LV #SN Attr   VSize  VFree
   vg1   1   1   0 wz--ns 19.97g 18.72g
sle15-c1-n1:~ # vgs -o+lock_type
   Reading VG vg1 without a lock.
   VG  #PV #LV #SN Attr   VSize  VFree  LockType
   vg1   1   1   0 wz--ns 19.97g 18.72g dlm
sle15-c1-n1:~ # vgchange --lockstart
   VG vg1 starting dlm lockspace
   Starting locking.  Waiting until locks are ready...
sle15-c1-n1:~ # lvs
   LV   VG  Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync 
Convert
   lv1  vg1 -wi------- 1.00g
"""

Thanks,
Eric