Topic: Speed of Tape Backups

[pearless]

I am looking to migrate from SME 6.01 to 7.

One of the issues I had with 6.01 was the extreme slowness of the backup caused by the "buffer".


There was a thread on this issue where I described how I eventually fixed it ( http://forums.contribs.org/index.php?topic=27431.0  ) is there the same issue with 7?

If it is NOT fixed in 7, I assume I will have to re-run this fix myself?

Cheers Douglas.

[CharlieBrady]

I am looking to migrate from SME 6.01 to 7.

One of the issues I had with 6.01 was the extreme slowness of the backup caused by the "buffer".


There was a thread on this issue where I described how I eventually fixed it ( http://forums.contribs.org/index.php?topic=27431.0  ) is there the same issue with 7?

If it is NOT fixed in 7, I assume I will have to re-run this fix myself?

Nothing gets fixed unless it is reported as a problem. Don't rely on the developers to read every thread in all forums.

To disable use of "buffer", you don't need to make any custom template changes. Just do:

config setprop flexbackup BufferProg false
signal-event conf-backup

Please add a detailed report of your problems with backup speed via the bug tracker. Thanks.

[pearless]

Nothing gets fixed unless it is reported as a problem. Don't rely on the developers to read every thread in all forums.

To disable use of "buffer", you don't need to make any custom template changes. Just do:

config setprop flexbackup BufferProg false
signal-event conf-backup

Please add a detailed report of your problems with backup speed via the bug tracker. Thanks.

Well I have come back to this issue to try and speed up my backups on my new server.

I found:
99GB, tar+hardware compression takes 2 hours 45 minutes
99GB, tar+gzip takes 3 hours 15 minutes
99GB, tar+gzip + mbuffer with a 1GB buffer takes 3 hours 50 minutes

I note that the bulk of the 99GB are jpeg files.

I am not sure, but it seems to me that mbuffer actually slows things down, and unless you are have a lot of compressible files, then gzip (which cause one of the cores of my 2x Xeon dual core 3.0GB processors to go to 96%) does not seem to be of much use either!.

Has anyone else found using mbuffer or buffer slows down their backups?

Note I am using a Compaq SDLT 110/220GB drive (which I note in the manual states that hardware compression is turned on by default) on its own SCSI controller (if fact there is nothing else on that controller) on a Compaq / HP ML370, dual Xeon dual core 3.06GHz, 5.5GB of RAM and U320 15k rpm drives in a hardware raid-5 configuration.

If this seems to be a general problem, then I will raise a "bug" and ask that buffer is turned off by default

Cheers
Douglas