Migration to Tape Performance problem

[BBB]

Make sure your stgpools and tape drives are not on the same HBAs.

What sort of disks are you reading off, ie what sort of storage and how many disks are the diskpools on?

 

[tsmchambers]

Host has 4 hba ports. 2 for the disk pool & 2 for tape.

The disk is hitachi usp-v, it is very fast since it is from an HDP pool.
We have 7 50gb luns on 7 raw logical volumes.

When the migration starts, the speed is tremendous, towards the end, it really dribbles.

 

[javajockey]

TSM migrates 1 node at a time, per migration process. It starts with the largest file first, then second largest and so forth. My process will hit 120MB, but only when there are really large files to migrate. Then it drops down to around 60 (per process). In other words,what you may be experiencing is normal, if you have a lot of small files.

 

[BBB]

What javajockey said made me think of something. Why not use more migration processes (multiple tape drives) during migration, this will increase your overall throughput.

See update stgpool <name> migprocess=<num>