fbackup speed

[Michael O'brien_1]

Hi,

I ran a backup of 46GB of data using fbackup to a Magstore 3590 located on another L-Class (on the same gigabit network). It took an extremely longtime, approximately 14 hours. Is this time normal for backuping this amount of data.

Thanks
Michael

[A. Clay Stephenson]

Hi Michael:

There are some things you can do to tune the speed of the backup operation. You will need to adjust some of the values in the fbackup config file that you are using.

I would look at these:
blocksperrecord
records
checkpointfreq
readerprocesses

You will need to play with these to determine what is best for your environment. Mna fbackup for details. The very first thing that I would do, however, is to test a similar local backup to see if the problem is the network.

This should get you started, Clay

[James R. Ferguson · Accepted solution]

Hi Michael:

The 'fbackup' configuration parameters are enumerated in the man pages for 'fbackup'. A default set is used if the 'config' file is absent, and are non-optimal.

I don't have any magic values for you to use. I like blocksperrecord=64 or 128 with a checkpointfreq=128 or 256 accordingly. The 'blocksperrecord' parameter has generally been shown to have the biggest impact with the 'checkpointfreq' also being important. I'd rather gain speed during backup and sacrifice it during recovery, so I don't worry too much about the parameters like 'filesperfsm'. Three to five retries for busy files is more than enough.

An excellent document is #KBRC00000196 "Understanding Fbackup/Frecover and Optimizing Backup Performance". I've attached it for your convenience.

Regards!

...JRF...

[Michael O'brien_1]

Thanks for all your help, next time I will run some test backups with the config files you have suggested. Generally we backup our systems via Tivoli which also has some issues but the information you provided regarding rec size/ blocks was very useful.

Once again thats for all your help