Re: Real World Experience - TS3100 tape library

On Fri, Jul 2, 2010 at 18:47, Graap, Kenneth
<Kenneth.Graap@xxxxxxxxxxxxx> wrote:

In my initial B/U test, the throughput was 77MB's / second. The IBM specifications for this configuration says the throughput could be as high as 120MB's / second.

120MB/s is LTO4. Do you have an LTO4 tape in your TS3100? Because
there are many different tape drives that can be fit into a TS3100.
LTO4 full-height and half-height drives have different performance
(the HH drives are slower).

If the LTO4 tape drive in your TS3100 is the only thing attached to
your U320 scsi controller, the SCSI bus performance should be good
enough (U320 has a theoretical max speed of 320 Megabytes/s, but
that's never reached in practice).

My test was done in a restrictive state against a library containing around 350GB's of large database files and their associated indexes.

And how did you measure that? By measuring the time it took the save
from start to finish? This doesn't measure the speed of the tape
drive, it measures the speed of the backup process.

Is anyone else using a SCSI attached TS3100? If so, what kind of throughput are you seeing?

We're using a Full Height LTO4 tape in a TS3100 that's SAS attached.
We're using this to save our Windows servers. The speed measured by
BackupExec (write speed to tape drive, not backup speed!) is around
100-110 MB, but the only time this is reached when backing up large,
contiguous files.

We will be replacing the UTLA3 SCSI connection with a fibre channel 5761 card in an attempt to get increased throughput and to allow for hardware encryption. I would be interested to know what kind of throughput others have seen using a fibre connection with the TS3100 drive too.

No idea. We have one customer that uses a fibre attached TS3200 with
two full height LTO4 drives, but we've never measured the speed.