On Tue, 18 Jan 2005 12:18:38 -0600, Jack Malone
I'm trying out the personal version of bru for backinging up some samab shares here. Just wondering who is using it out there an if you did any speed tweaks to increase the speed of backups. I did a test backup this morning of about 1 gig of data an it took 30 minutes to complete it. Based on that time frame the 11 gigs I have in the samba share would take up to 5 hours or so to finish. I did a test with the buffersize at 64k an 128k an it was same amount of time to do the backup in my testing. thanks for any help with this. I'm using a quantum DLT vS80 tape drive.
thanks
jack
That's pretty slow. It is bad for your DLT drive to run that slow, so you really do need to make the process faster. (i.e. The shoe-shining noises you are hearing are adding lots of wear and tear to the tape drive.) How long does it take if you backup your 1GB to /dev/null? How long does it take if you dd 1GB of /dev/zero to the tape (Be sure to adjust your block sizes)? Typically a slow backup is caused by traversing the filesystem, not the tape system. Assuming that it is bru (ie. the filesystem) that is slow, with only 11 GB you will be better off to do your BRU backup do a dedicated xfs filesystem on a dedicated drive. (ie. /dev/hdc1). Then just dd the backup file to tape. That way the tape / filesystem speed issues will not degrade each other. Overall, the $100 (or less) you spend to put in a backup staging disk will more than pay for itself by eliminating wear and tear on your DLT drive. FYI: This concept is also called a D2D2T (Disk to Disk to Tape) backup strategy, or a mezzanine backup strategy. The more sophisticated versions keep several recent backups on disk and restores from those recent backups come in directly from disk. Greg -- Greg Freemyer