zfs discuss - Oct 2010 - rename zpool

Hi,

I have two questions:
1) Is there any way of renaming zpool without export/import ??

2) If I took hardware snapshot of devices under a zpool ( where the snapshot
device will be exact copy including metadata i.e zpool and associated file
systems) is there any way to rename zpool name of snapshotted devices ?? 
without losing data part?

Thanks & Regards,
sridhar.
-- 
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Hi Sridhar,

The answer to the first question is definitely no:

No way exists to change a pool name without exporting and importing
the pool. I thought we had an open CR that covered renaming pools but I
can''t find it.

The underlying pool devices contain pool information and no easy way
exists to change the pool info at the device level so this is also a
no, if I understand what you are asking correctly.

Thanks,

Cindy

On 10/19/10 08:51, sridhar surampudi wrote:
> Hi,
> 
> I have two questions:
> 1) Is there any way of renaming zpool without export/import ??
> 
> 2) If I took hardware snapshot of devices under a zpool ( where the
snapshot device will be exact copy including metadata i.e zpool and associated
file systems) is there any way to rename zpool name of snapshotted devices ?? 
without losing data part?
> 
> Thanks & Regards,
> sridhar.

Hi Cindys,

Thank you for reply. 

zfs/ zpool should have ability of accessing snapshot devices with a configurable
name.

As an example if file system stack is created as 
vxfs( /mnt1)
  |
  |
vxvm(lv1)
  | 
  |
(device from an array / LUN  say dev1),


If i take array level or hardware level snapshot, and the snapshot device for
dev1 is say dev2 then we can rename dev2 properties to access the dev2 with new
name say lv1_snap. And further access file system
with /mnt1_newmount.

This also can be done if hplvm also present.

I am looking for similar kind of ability with zfs/zpool presence.

  zfs (smpool/fs1)
       |
       |
  smpool
      |
      |
 (device from an array / LUN  say dev1)

Once I took array or hardware snapshot of dev1 and got dev2, I am looking for
something which I can access the snapshot device dev2 is accessible with
smpoolsnap or any name keeping smpool active.
And further fs1 is accessible as smpoolsnap/fs1  as read only. 

If zfs/zpool do not have this support is there a way I can open an issue so that
in next releases it will be available ??

Thanks & Regards,
sridhar.
-- 
This message posted from opensolaris.org

On 10/20/10 08:12 PM, sridhar surampudi wrote:
> Hi Cindys,
>
> Thank you for reply.
>
> zfs/ zpool should have ability of accessing snapshot devices with a
configurable name.
>
> As an example if file system stack is created as
> vxfs( /mnt1)
>    |
>    |
> vxvm(lv1)
>    |
>    |
> (device from an array / LUN  say dev1),
>
>
> If i take array level or hardware level snapshot, and the snapshot device
for dev1 is say dev2 then we can rename dev2 properties to access the dev2 with
new name say lv1_snap. And further access file system
> with /mnt1_newmount.
>
> This also can be done if hplvm also present.
>
> I am looking for similar kind of ability with zfs/zpool presence.
>
>    zfs (smpool/fs1)
>         |
>         |
>    smpool
>        |
>        |
>   (device from an array / LUN  say dev1)
>
> Once I took array or hardware snapshot of dev1 and got dev2, I am looking
for something which I can access the snapshot device dev2 is accessible with
smpoolsnap or any name keeping smpool active.
> And further fs1 is accessible as smpoolsnap/fs1  as read only.
>
> If zfs/zpool do not have this support is there a way I can open an issue so
that in next releases it will be available ??
>
>    
What''s wrong with a snapshot of smpool, or if you want read/write, a 
clone of a snapshot of smpool?

-- 
Ian.

zfs close is at zfs file system level. what i am look here is rebuild the file
system stack from bottom to top. Once i took the snapshot ( hardware) the
snapshot devices carry same copy of data and meta data.

If my snapshot device is dev2 then, the metadata will have smpoolsnap. If I need
to use dev2 on the same machine since smpoolsnap is already present on dev1
which throws error.
what I am looking for is if I can modify this metadata, I can use dev2 with an
alternate name so that all file systems would be available with an alternate
zpool name.

As I mentioned below, I can do it for HPLVM or AIXLVM ( recreatevg command) if i
create a snapshot at array level.

Thanks & Regards,
sridhar
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