topic Re: EVA + Windows + host cache flush in Disk Enclosures

EVA + Windows + host cache flush

Maxitaly_1 — Tue, 23 Jan 2007 06:19:33 GMT

Hi all

Configuration example:
- EVA 6000
- SRV1 Windows 2003 mount on X: a vdisk (vdisk0 for example)
- SRV1 share X: (file server)

Question: when I create a snapshot of vdisk0 using CV graphical interface, how can I be sure that the Windows cache is flushed on disk before the snapshot execution ?
I can change the cache mode of the vdisk0 (WRITETHROUGH), but I think that this operation only flushes the data of the EVA controllers.

Thanks for help
Armando

Re: EVA + Windows + host cache flush

Uwe Zessin — Tue, 23 Jan 2007 09:16:38 GMT

simple answer: you can't do that with CV, sorry.

The Replication Solutions Manager (RSM, which is licensed with the BC-EVA or CA-EVA license) has a host agent and the necessary means (function call) to tell the host to flush the file system.

Re: EVA + Windows + host cache flush

Maxitaly_1 — Tue, 23 Jan 2007 09:22:55 GMT

Thanks Uwe.

I found a sysinternal util: sync. Do you think that this utility can help me ?

Re: EVA + Windows + host cache flush

Uwe Zessin — Tue, 23 Jan 2007 09:32:27 GMT

Yes, you could even do a "poor man's RSM" by creating a script which calls "sync" and then initiate the snapshot via SSSU.

Re: EVA + Windows + host cache flush

Vincent Fleming — Wed, 24 Jan 2007 08:37:26 GMT

Another way is to use VSS snapshots...

You can get the EVA VSS Providers here: http://h18004.www1.hp.com/products/storageworks/vdsvsshard/index.html?jumpid=reg_R1002_USEN

With these, you can use the standard Windows Volume Shadow Copy service to create BC snapshots.

Good luck,

Vince