can array do what I want?

[Dave Chamberlin]

I am looking at a getting a VA7410 disk array. I understand it can connect to two hosts. I want to be able to share files between the servers for data refreshing etc. Can I do that with this array? If not - what is the advantage of the 7410 over the 7400? Can someone clarify what I might get with the 7410 over the 7400?
Thanks

[Leif Halvarsson_2]

Hi,

Maybe you talk about two different things.

- If two servers can access the same physical (or logical) volume (LUN).
- If two servers can access the same filesystem (and files).

The first case is hardware related, if the controller has two host connection and it is possible to assign a LUN to both hosts. I have no experience with 7410 but, for ex. with a SAN array that part had not been any problem.

The second problem is software (OS) related. If two servers should have direct access to the same filesystem you need a filesystem which allow that. Some kind of "cluster filesystem" or what it is called. With "ordinary" filesystems"it is not possible. Or, maybe possible if one host mount it as "read only".

[Alzhy]

You can present LUNs from the array so that they're visible to the 2 hosts -- but only one host can have control over them at any one time. For data refresh purposes (ie, DB refresh) .. if youre data sets are not really huge - then create a VG on host1 which shall receive copied data (via dd/vxdump-restore/cpio) from your production data... of course you will need DB downtime for the duration of the copy. Once the copy is done, export the VG on host 1 and import on host2 and mount the filesystems.


If you do not want disruption on host1 AND cannot afford Business Copy (the other in-array solution).. then you can consider VxVM mirroring (you will need to purchase the full License though..). VxVM supports splitting mirrored volumes (host-based) and creating a new diskgroup that contains the split mirrors. That diskgroup can thence be deported from host 1 and imported on host 2. The whole operation canbe done with no noticeable impact to production.