Very Slow Backup Times / Media Mount Latency
Symantec Backup Exec 10d for Windows Servers (Small Business Server Suite) Version 10.1 Rev 5629
Windows Server 2003 SBS SP2 (32-bit)
Intel Xeon 3.0GHz
I've been suffering with this issue for quite awhile now and I suppose it's time to address it. A full backup of ours is about 600-700GB in size. Our incremental backups go to a tape drive (and can take around 56 hours), but our full backups go to an eSATA external 1TB hard drive. I start from a quick formatted external drive every time. A full backup has been known to take 100+ hours. I think that's completely ridiculous. I attribute some of the latency to our slow server, however I've come to the realization that this can't be the only cause. Since I cannot do backups over a weekend, it has begun to affect normal business.
Recently, I looked at the amount backed up at certain times throughout the backup and noticed something a bit strange. It seems the backup time "exponentially" increases as there are more bkf files created. For instance, in the first 4 hours, it backed up 110GB. The last 9 hours backed up 37GB. I looked at the log and noticed that I see a media mount for each of the files created in the backup. Currently, it is set to the 1GB file size default. Probably not a problem, but I then notice that the time between the "media mount request" and the "media information from media mount" time is ever increasing.
The First Mount (5 seconds)
Drive and media mount requested: 3/9/2012 2:55:12 PM
Drive and media information from media mount: 3/9/2012 2:55:17 PM
The Last Mount (13 minutes 4 seconds!)
Drive and media mount requested: 3/12/2012 8:58:42 AM
Drive and media information from media mount: 3/12/2012 9:11:46 AM
You can imagine how much time is wasted if you have hundreds of bkf files. During this mount time, Backup Exec displays "loading media".
1. What exactly is happening during this time? Why is it taking an ever increasing time? Why can it take 13 minutes or more? What can I do to speed this up?
2. I know I could increase the "Maximum size for Backup-to-Disk files", which would decrease the number of these media mounts significantly. Although I might be better resolving the root problem based on answers to question #1. Are there any general guidelines or pros/cons to particular sizes to bump it to? I was thinking something like 10-25GB. The bigger, the better depending on the cons list.