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7.7.3 VMware Accelerator Backups - OST Storage Tuning Question

GeForce123
Level 5

I'm trying to do some fine tuning of my VMware backups.

Environment is NBU 7.7.3
Media Server - Linux OUL
VM Backup Host - Linux OUL Media Server
vSphere 6.5
SIZE_DATA_BUFFERS - 262144
NUMBER_DATA_BUFFERS - 128

The bpbkar and bptm waits & delays for a VMware job that ran for 2:48:27

05/23/2018 00:23:30 - Info bpbkar (pid=26236) bpbkar waited 3983 times for empty buffer, delayed 8524522 times
05/23/2018 00:30:14 - Info bptm (pid=26333) waited for full buffer 16 times, delayed 35557 times

  I get that the media server waited for the full buffers for 8.8 minutes based on the 15millisecond (.015) delay.

Is there no tuning that could decrease the delays for empty buffers?

Recently I tried to adjust the SIZE_DATA_BUFFERS to 1MB and the NUMBER_DATA_BUFFERS to 64 and I didn't see much improvement in the overall performance.

 

2 REPLIES 2

Nicolai
Moderator
Moderator
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Try setting NUMBER_DATA_BUFFERS_DISK and SIZE_DATA_BUFFERS_DISK

It looks like backup data is waiting to be written to disk. 

Is destination disk MSDP, Data Domain or something else ?

Hey Nicolai. The destination disk is HP StoreOnce OST. I already added the NUMBER_DATA_BUFFERS_DISK (64) and SIZE_DATA_BUFFERS_DISK  (1MB) and let the jobs run for a day (had the long weekend come up and changed the _DISK touch files so that backups would use what it previously had been.

The backup data that is waiting to be written to disk, is that the same parent delay of 15ms? If the bpbkar delay timer is the same delay, the number of times it waits/delays for bpbkar is longer than the actual job runs.