Actually, I did this very thing a couple of years ago with M9000s and EMC DMX4s ... with the exception of the "same host" requirement you have (i.e. the thing that requires the GUID change).
If you want to import the pool back into the host where the cloned pool is also imported, it's not just the zpool's GUID that needs to be changed, but all the vdevs in the pool too. When I did some work on OpenSolairis in Amazon S3, I noticed that someone had build a zpool mirror split utility (before we had the real thing) as a means to clone boot disk images. IIRC it was just a hack of zdb, but with the ZFS source out there it's not that impossible to take a zpool and change all its GUIDs, it's just not that trivial (the Amazon case only handled a single simple mirrored vdev). Anyway, back to my EMC scenario... The dear data centre staff I had to work with mandated the use of good old EMC BCVs. I pointed out that ZFS's "always consistent in disk" promise meant that it would "just work" but that this required an consistent snapshot of all the LUNs in the pool (a feature in addition to basic BCVs that EMC charged even more for). Hoping to save money, my customer ignored my advice, and very quickly learned the error of their ways! The "always consistent on disk" promise cannot be honoured if the vdev are snapshot at different times. On a quiet system you may get lucky in simple tests, only to find that a snapshot from a busy production system causes a system panic on import (although the more recent automatic uberblock recovery may save you). The other thing I would add to your procedure is to take a ZFS snapshot just before taking the storage level snapshot. You could sync this with quiescing applications, but the real benefit is that you have a known point in time where all non-sync application level writes are temporally consistent. Phil http://harmanholistix.com On 15 Nov 2010, at 10:11, sridhar surampudi <toyours_srid...@yahoo.co.in> wrote: > Hi I am looking in similar lines, > > my requirement is > > 1. create a zpool on one or many devices ( LUNs ) from an array ( array can > be IBM or HPEVA or EMC etc.. not SS7000). > 2. Create file systems on zpool > 3. Once file systems are in use (I/0 is happening) I need to take snapshot at > array level > a. Freeze the zfs flle system ( not required due to zfs consistency : source > : mailing groups) > b. take array snapshot ( say .. IBM flash copy ) > c. Got new snapshot device (having same data and metadata including same GUID > of source pool) > > Now I need a way to change the GUID and pool of snapshot device so that the > snapshot device can be accessible on same host or an alternate host (if the > LUN is shared). > > Could you please post commands for the same. > > Regards, > sridhar. > -- > This message posted from opensolaris.org > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
