IBM Storage Snapshot Latency Issue

[crackocain]

Hello

Case #03969026 — IBM Storage Snapshot Optimizing
Closed Feb 19 2020. Veeam support say "this problem fix V10 Update 1"

So all IBM users have to know this snapshot behavior.

The problem;
When we use IBM Storage snapshot, volume write latency going up.
IBM Flashcopy need a buffer capacity for write io's. This feature is "real capacity size"
So if you want create flashcopy snapshot real capacity size have to be at least 2 GB
But veeam trigger snapshot with 0 GB real capacity size. So write latency is much higher in IOmeter test. 11 ms to 241 ms!

Thats why we disabled storage snapshot feature all database volumes. This problem is critical for many enterprise customers.

I suggest to Veeam real capacity size registry key for Veeam Backup & Replication so this way customer input number whatever wants.

IBM Software Architect Andrew Martin and Barry White mentioned this optimizing in his blogs.
https://barrywhytestorage.blog/2020/01/ ... snapshots/

[Andreas Neufert]

If I undersstand you post correctly, then v10a (Update1) fixes this.
It is available here: https://www.veeam.com/kb3228

[crackocain]

Thank you Andreas

Could you share the registry key for this problem? How am i implement the solution? Can i open a case?

[Andreas Neufert]

Based on what I see in the internal support ticket, the installation of the Update is enough. To get the Software use the download location mentioned in the KB or if still no available there, please open a support ticket and request access to v10a update. (I guess you can use the same ticket as above?)

[crackocain]

Hello everyone

If you suffer write latency when enable storage snapshots in IBM Spectrum Virtualize, you may implement below registry key. At first you have to update Veeam 10a...

HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and Replication\
Type: REG_DWORD 32
Value Name: IbmSnapshotRSizeInGb
Value Data (Decimal): 2