As Allen said, find a way to measure the throughput. We use mrtg for this, which gives us some nice graphical long-term history. We have 8 remote LTO4 drives, each on it's own 1GE IP connection. The 8 1GE connections are merged onto 1 10GE long-haul network route. We're using Cisco gear with tape acceleration for FCIP and it seems to be working very well.
Details: Server: P5 570 Tape: IBM 3584, LTO4 drives, with application(TSM)-enabled encryption. Most of our data is compressed at client Distance: 200-250 miles Most of the time, we see performance comparable to local tape. When we reclaim remote tape, we source from local tape (to avoid bogging down network link). We do this by marking all of the full remote tapes as "offsite", which forces TSM to read input from the local tapes. This makes the remote library pretty much write-only, except when we really need it. ..Paul At 03:44 PM 1/28/2010, Hart, Charles A wrote: >We push our 2nd copy over individual FCIP links with write acceleration >enabled, we use to trunk 6gige links together but ran in to latency >issues without write acceleration enabled and the technology did not >allow for write acceleration and trunking so we end up with 3-4 LTO4 >drives down 1gige link with write acceleration. > >That said when I run select against the summary table to get timings on >Backup stgpools the more the more processes we kick off at one the >slower the speed (makes sense only so much per gige). (TSM Env AIX p550 >/ IBM LTO4) > >LTO4's minimum matching drive speed is 30MBS, so once we push 4 >processes down one link we are pushing less than 30MBS, thereby in >theory running below the minimum rated drive speed we should be shining >the drives pretty good. Does anyone know of a way to validate that >indeed were shining? > >Regards, > >Charles > > >This e-mail, including attachments, may include confidential and/or >proprietary information, and may be used only by the person or entity >to which it is addressed. If the reader of this e-mail is not the intended >recipient or his or her authorized agent, the reader is hereby notified >that any dissemination, distribution or copying of this e-mail is >prohibited. If you have received this e-mail in error, please notify the >sender by replying to this message and delete this e-mail immediately. -- Paul Zarnowski Ph: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801 Em: p...@cornell.edu