[linux-lvm] pvmove of lvs while filesystems mounted not supported?!?

[linux-lvm] pvmove of lvs while filesystems mounted not supported?!?

[Edward Quillen]

Redhat support is telling me (see quote below) that pvmove is not supported when there are mounted
filesystems on top of the lvs that are being moved. Can this be true? Everyother lvm that I have
worked with allows this. I am currently experiencing device mapper hangs when I run pvmove while
there are filesystems mounted even if there is no processes using the filesystems. 
Is this supposed to work? If so, has anyone had similar issues? Any help would be appreciated? 

Thanks,
Ed
ed@quillen.net

server info:

<Z>sys66# uname -a
Linux sys66.kelly.com 2.6.9-34.ELsmp #1 SMP Fri Feb 24 16:56:28 EST 2006 x86_64 x86_64 x86_64
GNU/Linux
<Z>sys66# rpm -qa | egrep 'lvm|device-map'
device-mapper-1.02.02-3.0.RHEL4
lvm2-2.02.01-1.3.RHEL4
system-config-lvm-1.0.16-1.0
device-mapper-1.02.02-3.0.RHEL4


redhat response:

Hello,
The pvmove command attempts to move all of the data off the pv for a vg. Since the pvmove cannot
lock the vg from putting information back on the pv this operation does not work. A pvmove is
normally done when a the vgs\lvs connected to it are not mounted. Once the pvmove is completed you
would start removing the space allocated to the vg. This operation is not supported while the
assocated filesystems are mounted.

Thank You

Re: [linux-lvm] pvmove of lvs while filesystems mounted not supported?!?

[David Brown]

Edward Quillen wrote:
> Redhat support is telling me (see quote below) that pvmove is not supported when there are mounted
> filesystems on top of the lvs that are being moved. Can this be true? Everyother lvm that I have
> worked with allows this. I am currently experiencing device mapper hangs when I run pvmove while
> there are filesystems mounted even if there is no processes using the filesystems. 
> Is this supposed to work? If so, has anyone had similar issues? Any help would be appreciated? 

Requiring an unmount of the filesystem would kind of defeat the purpose 
of pvmove.  In that case, just create a new volume and dd the data across.

pvmove creates a mirror for each segment it is moving.  That way updates 
will be written to both segments while the mirror is active.

I've done it numerous times, including moving very active filesystems 
off of a flaky drive so that I could replace it.

Dave Brown

Re: [linux-lvm] pvmove of lvs while filesystems mounted not supported?!?

[Dave]

Hi David & list readers,

I am still stuck using LVM1 (1.0.8-14) on a RedHat AS3 system (kernel:
2.4.21-47.ELsmp) and may need to move all data from the existing disks to a new set
of disks.

Can I safely use pvmove (under LVM1) to perform this action while the file systems
are mounted or not?  If not, are there other ways LVM can help move all data to the
new disks without having to unmount the file systems in use?  

Thanks,
Dave

--- David Brown <lvm@davidb.org> wrote:

> Edward Quillen wrote:
> > Redhat support is telling me (see quote below) that pvmove is not supported when
> there are mounted
> > filesystems on top of the lvs that are being moved. Can this be true? Everyother
> lvm that I have
> > worked with allows this. I am currently experiencing device mapper hangs when I
> run pvmove while
> > there are filesystems mounted even if there is no processes using the
> filesystems. 
> > Is this supposed to work? If so, has anyone had similar issues? Any help would
> be appreciated? 
> 
> Requiring an unmount of the filesystem would kind of defeat the purpose 
> of pvmove.  In that case, just create a new volume and dd the data across.
> 
> pvmove creates a mirror for each segment it is moving.  That way updates 
> will be written to both segments while the mirror is active.
> 
> I've done it numerous times, including moving very active filesystems 
> off of a flaky drive so that I could replace it.
> 
> Dave Brown
> 
> _______________________________________________
> 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/
> 



 
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Re: [linux-lvm] pvmove of lvs while filesystems mounted not supported?!?

[Jonathan E Brassow]

I've never tried it using LVM1, but I'm told it is safe.

  brassow

On Nov 13, 2006, at 7:47 AM, Dave wrote:

> Hi David & list readers,
>
> I am still stuck using LVM1 (1.0.8-14) on a RedHat AS3 system (kernel:
> 2.4.21-47.ELsmp) and may need to move all data from the existing disks 
> to a new set
> of disks.
>
> Can I safely use pvmove (under LVM1) to perform this action while the 
> file systems
> are mounted or not?  If not, are there other ways LVM can help move 
> all data to the
> new disks without having to unmount the file systems in use?
>
> Thanks,
> Dave