SnapShot scripting/ Automated processing

[Andy McCreath]

I wanted to get my head around the SS scripting tool on the MA, with the concept of creating a list of shots, presenting them to one host & taking a near-line backup off of that host.
The thing is I have no idea of the limitations & presentation issues that may be associated with this concept, so any documentation would be helpful.

Many thanks,

[Sheldon Smith]

MA? Like the MA8000 (HSG-based) storage? I did not think they had a snapshot function.

[Sheldon Smith]

Nevermind. I had forgotten about the ACS 8.xS optional snapshot software.

[Michael Schulte zur Sur]

Hi,

could you give us more information about your configuration?

Michael

[Andy McCreath]

Config is EVA5000, dual controlers, Dual zoned Silkworm12000.
I want to snap various file servers and present them to a single host to enable us to backup up from that one host.

[Alzhy]

Frankly, I would rather that my BC clients run the jobs instead of them being run on the MA (SAN Management Appliance). Once the Jobs are defined on the MA and tested manually, it'll be up to the UNIX or NT Admin to write his/her own script using whatever tools available that will run "evmcl" to run the job.

[Mike Naime]

Andy:

We do this for aprox 200 AIX/VMS servers. Unfortunatly, the guy that does all of this scripting does not frequent these boards. I have used the scripting tool for creating new LUNS, but not for the snapshots.

[Orrin]

Hi Andy,

The scripting is pretty straight forward as far as creating the snapshots and presenting them to the BC host is concerned.

The important thing is to stop the files being updated when the snapshot is taken.

This will have to be done before the script for the snapshot is launched.

you can find documentation at this site:

ftp://ftp.compaq.com/pub/supportinformation/techpubs/user_reference_guides/aa-ru5hc-te.pdf

Hope this helps...

Regards,
Orrin.

[Sheldon Smith · Accepted solution]

Whether you are using Business Copy scripts or SSSU, the underlying process is still the same. The Storage Server Scripting Utility (SSSU) talks to the SAN Appliance via TCP to control the EMA. You can create and delete vdisks and snapshots, and present and unpresent them to desired hosts. Business Copy gives a nice interface and makes error handling and post-backup cleanup simpler.

As mentioned earlier, you will want to look at the "HP StorageWorks Storage System Scripting Utility - Enterprise Virtual Array" (available at http://h18006.www1.hp.com/products/sanworks/managementappliance/documentation.html)
for the complete syntax. Any SSSU script starts with a SELECT MANAGER command to establish communications to the appliance, followed by a SELECT CELL command to choose which storage cell will be controlled.

Any anciliary functions, such as pausing/quiescing a database prior to the snapshot(s) and then resuming same after would need to be scripted outside of SSSU. (You were going to pause the database prior to snapshot to get a consistent view, weren't you? -- ) Also, functions such as mounting and dismounting the snapshot is also an OS function and done outside of SSSU.

When creating the snapshot(s), the default is to still use a full-allocated snapshot (the original functionality). You will probably want to specify demand-allocated snaps when creating them.
When presenting the snapshots, you are responsible for choosing and maintaining the EVA-host LUN assignments. Since an EVA controller pair will track LUNs to a particular host from 1 to 255, finding available ones should not be a problem. Since the Command View EVA GUI will automatically choose the lowest available LUN when presenting to a host, pick a block of LUNs in the upper end of the LUN range.

So a script to snap a database (residing across three volumes) and back it up would look (metadata-ly) like:

DB-util "pause database"
SSSU <script file>
SELECT MANAGER ....
SELECT CELL ....
ADD SNAPSHOT ALLOCATION_POLICY=DEMAND STORAGE= ...
ADD SNAPSHOT ALLOCATION_POLICY=DEMAND STORAGE= ...
ADD SNAPSHOT ALLOCATION_POLICY=DEMAND STORAGE= ...
EXIT
DB-util "resume database"
SSSU <script file>
SELECT MANAGER ....
SELECT CELL ....
ADD LUN STORAGE= HOST=
ADD LUN STORAGE= HOST=
ADD LUN STORAGE= HOST=
EXIT
OS-Mount ...
OS-Mount ...
OS-Mount ...
OS-Backup ...

Cleanup afterwards involves unmounting the LUNs from the backup host then deleting the snapshots:

OS-Dismount ...
OS-Dismount ...
OS-Dismount ...
SSSU <script file>
SELECT MANAGER ....
SELECT CELL ....
DELETE LUN
DELETE LUN
DELETE LUN
DELETE STORAGE
DELETE STORAGE
DELETE STORAGE
EXIT

That should get you started....

[Uwe Zessin]

Andy,

if I recall correctly there is a limit of 8 concurrent BC (Business Copy) jobs on the SMA (Storage Management Appliance). Deleting Snapshots on the EVA can take quite a while, so I would run some timing tests.