Data backup average times - any input appreciated

[dellboy]

W2k Sp2
BE v8.6
RAID 5 hardware

I am backing up the file server, currently in 2 seperate backups due to time and data compression. I am using 40/80 tapes but the tapes do not want to take any more than 53Gb, the job then stops. I am now running 2 seperate jobs and these are the times for the data to backup - (both jobs run a virus check, Verify, Write check sums to media and hardware if avaliable otherwise software compression).

40Gb - 9.5hours
26Gb - 5.5hours


Does this amount of time seem appropriate in your experience? I thought it would be quicker. Any advice or comparison appreciated

Cheers

 

[2ffat]

That looks about right. There are a lot of varaibles, speed of network, what other processes are running that are CPU intensive, throughput on bus and backup machine, etc., etc..

Your 40/80 tapes will rarely hold 80GB. That is an estimate based upon 2:1 compression ratio (a perfect compression ratio). That rarely happens in real life. We get between 1.2:1 to 1.6:1 compression on our machines. That sounds about the same as you are getting. You have to remember that some files (like ascii files) will get greater compression than others (like executables). If you have more files that can be compressed than cannot, you will get a better ratio than if you have the opposite. At the worst case, if you have a machine that has no files that can be compressed, you will get a 1:1 ratio. This is about as rare as a machine with perfect compression.
James P. Cottingham

I am the Unknown lead by the Unknowing.
I have done so much with so little
for so long that I am now qualified
to do anything with nothing.

 

[Zelandakh]

As James says, 30% compression is about what you can expect. As to time, find out the speed of your SCSI chain. On a SCSI 3, expect to get 60MB/minute.

 

[StevieWonder]

I have no problems with the average time of the backups.
I get even 93 GB on a 40/80 GB tape!! I'm only using hardware compression, software compression takes to much CPU. We have Ultra-Wide SCSI-3 en the tape drive is internal and get about 350 MB/minute!
Lucky me!

StevieWonder

PS When you insert a tape, what lights on the DLT tapedrive are burning? Perhaps your tape settings in BE are incorrect or a wrong driver.