On Wed, Nov 5, 2008 at 8:42 AM, David Lloyd <[EMAIL PROTECTED]> wrote:
> Does anyone know of a script / program I can run on a windows 2003 server to
> check i/o speed to an external scsi tape drive?

  To build upon other replies:

  I would try a combination of real-world and "synthetic" tests.  In
other words, try the tape drive manufacturer utilities, try something
third-party benchmarks, and try actually backing up different types of
files.  This will help give you a picture of where performance
bottlenecks are.

  A manufacturer utility will often bypass a lot of subsystems:
Certainly the hard disks, and some even use commands using the drive's
built-in intelligence, meaning even the SCSI bus doesn't get much
activity.  So if that's slow, there's something wrong with the tape
drive, or *maybe* the SCSI host adapter.

  A synthetic benchmark will run data through the SCSI bus to the
tape, but won't stress RAM, hard disks, disk controllers, or anything
else a real backup would.  So if the manufacturer utility is fast but
the benchmark is slow, that's a sign of an under-performing SCSI bus.
Check cables, host adapter, and host adapter driver.

  A "real world" test (running a dummy backup) stresses everything.
That's a poor way to test a tape drive, but it will show you what you
can realistically expect to get from the system as a whole.  And by
comparing with the above, maybe you can discover you have a slow disk
subsystem, filesystem, or the like.

  When you do your dummy backups, also compare different filesets.
You'll see different performance from backing up one big file vs
backing up a large number of small files.

-- Ben

~ Finally, powerful endpoint security that ISN'T a resource hog! ~
~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/>  ~

Reply via email to