2008/9/25 Joshua Baker-LePain <[EMAIL PROTECTED]>: > On Wed, 24 Sep 2008 at 6:10pm, Jamie Penman-Smithson wrote >> I'm trying to understand why amanda (v2.6.0p2, on RHEL4) is taking so >> long to backup just 60 Gb, the actual taping appears to only take a >> fraction of the time. I've double checked that compression is not >> enabled and in the report (see below) the estimation takes a grand total >> of 0 minutes. Actually writing the data to tape only took 35 minutes, >> the dump time was over 4 hours, over 11 hours without using a holding >> disk (holdingdisk never). >> >> The tape server and client are one and the same, it's backing up a local >> filesystem. > > What kind of hardware are we talking about here? How exactly are your disks > set up? Where is the holding disk in relation to the filesystem being > backed up? What does the data look like (i.e., are there a few big files, > or *lots* of small files)? What type of tape drive?
The holding disk is on a local [lowly] IDE drive. The data being backed up is on the whole comprised relatively large (couple of gig) files stored on SAN over fibre. At first I thought that the adverse performance was due to the IDE disk, however after disabling the holding disk it actually takes 4 hours longer to complete. I've considered using memory (/dev/shm) as a holding disk, however this is only 500 MB and I'm not sure if having such a small holding disk would make any difference. The tape drive is part of an IBM TotalStorage 3582 tape library. While at the moment I'm only attempting a backup of 60 GB, eventually it'll be backing up around 2 TB. Thanks, -- -Jamie L. Penman-Smithson <[EMAIL PROTECTED]>
