MSA Storage

MSA P2000 G3; Question on Volumecopy, mounting the Clone (destination) Read+Write from another host

Occasional Advisor

MSA P2000 G3; Question on Volumecopy, mounting the Clone (destination) Read+Write from another host

We are planning to move a volume (LUN) from one vdisk/enclosure#1 to the other vdisk/enclosure#2

We are somewhat familiar with volumecopy operation, for example scenario:

# volumecopy source-volume Encl01_v000 dest-vdisk Encl02 Encl01_v000_Copy
(volume: Encl01_v000 (sits on enclosure#1/vdisk#1) to be copied over to new volume “Encl01_v000_Copy” on vdisk Encl02, vdisk is on enclosure#2)

This is a 1-1.5 TB volume, and we expect this will take some time while MSA and volumes are active.

Question is: while this volumecopy operation is running, we would like to map/present/mount the volume "Encl01_v000_Copy" to another host (windows file-server#2), so that users can start using it (writing/updating of some files may be performed). We know a clone is created, and a full-copy is run on MSA in the background.

Immediatley after starting the volumecopy operation, if we present this "Encl01_v000_Copy" volume to fileserver#2, and users start using this drive (G:\), and begin to edit/modify their files/documents, would these changes be preserved, or over-stepped while the volumecopy operation is still in progress? Obviously, changes to this Encl01_v000_Copy volume from fileserver#2 are newer blocks, and we hope these blocks are preserved over the ones which are being copied-over from master-volume "Encl01_v000"


As you can figure - our goals:

 1) Migrate a large volume from one Enclosure#1 to Enclosure#2 using "volumecopy"

 2) During this volumecopy, we want to minimize the downtime to users (by presenting the clone "Encl01_v000_Copy")

 3) We would like to preserve the updates/changes done to "Encl01_v000_Copy" volume, without "volumecopy" overstepping on these updated/modified blocks.

Please shed your expertise, and confirm

Occasional Advisor

Re: MSA P2000 G3; Question on Volumecopy, mounting the Clone (destination) Read+Write from another h

# show volumecopy-status
VC Volume Name        Serial Number                     Vdisk                 Source Volume         Progress Status             Status-Reason
Encl01_v001_CC        00c0ff129a550000fc2f184f02000000  Encl01                Encl01_v001_Copy      8%       Unavailable        VC In Progress
Success: Command completed successfully.


Help on volume-copy shows:


  Indicates whether the destination volume is Unavailable or Suspended

  The status is Unavailable while the volume-copy is in progress.


Also in documentation:


While the operation is in progress, the destination volume is offline and its type is shown as “standard*”.

If the task succeeds, the destination volume’s type becomes standard and .. optionally map the volume to hosts.


From these notes: it appears that the destination volume (being copied-to) is un-available and NOT-mappable to hosts until volumecopy finishes.