2012-01-06 07:49 AM
Best wishes for 2012
Does someone know what type of IO is generated (normal or sequential) during backup node type=backupimage (TSM command)?
I checked with TPC and see only normal read IO during backup (I expected sequential IO), so when we performed a full backup we have bad performance due to disk (SATA) and only read cache hit ratio to 40%.
Read cache hit ratio is checked on backend (DS8700), do you know a tool to check on N6040?
Do you know a way to improve backup performance?
FYI we have same performance pb with some big volumes (10T) or little volumes (300G)
Thank you for your help
2012-01-09 08:41 AM
I think with full backup there is not many ways to improve the performance, as you are doing a lot of sequential reads, which ONTAP doesn't like too much (I have no idea why TPC is reporting there is no sequential IO - this is wrong in my opinion)
If we are talking about incremental backups, then TSM 6.1 or later is definitely better than earlier versions performance-wise:
“NetApp Snapshot Difference API enables TSM to reduce the time required for progressive incremental file backups by eliminating client filesystem scans.”
2012-01-10 08:33 AM
Find hereunder some screeshots from TPC, there was no other disk activities except TSM backup with NDMP.
There is no sequential IO during backup (backend is 6 SATA disk ranks on DS8700).