I have no experience with ISCSI, so I don't know how well that techology works with tape drives.
But I have done a campus-distance solution with a remote tape library connected by fibre. If you can manage a remotely connected library, that is WAY superior than the other choices. Drawback of virtual volumes: Virtual volumes can be messy to manage. When you have IP connection errors between the two servers, I have not found the messages to be helpful or easy to resolve. To do a DR recovery, you still need to rebuild the primary TSM server and have them BOTH up before restoring clients. And RECLAIMS are especially nasty: to reclaim data, it has to travel from the remote server, back to the buffer in the primary server, then back to the remote server. Drawback of PTAM: This is the cheapest solution, for sure. No extra hardware required. A major drawback is that the tapes you send offsite probably won't be collocated. When you have a DR situation, you first have to get the tapes and carry them to your DR site. Then get a TSM server working & restore the DB. Then it can take a zillion mounts to recover one client, and you may be very limited by the number of drives available. Using a remote library: Assuming you have the connectivity issues worked out, It is VERY easy to implement. TSM just knows you have 2 libraries. Primary pool in one, copy pool in the other. TSM doesn't care that they aren't located in the same building. Tapes collocated in both libraries. In a DR situation, all you have to do is provide connectivity to a DR TSM server, reload the data base, and start restoring. We have even ordered a spare server to sit offsite as a backup Domain controller and stand-by TSM server. We won't have to restore AD because it will have failed over to the spare domain controller, and we'll have TSM already installed, so all we have to do is restore the TSM DB and we're ready to rock. In one of the networks we're planning on an all-disk cabinet instead of a primary tape pool. We're locating the DISK offsite, and the tape library for the copy pool ONSITE. That way we not only have the data collocated, we have an unlimited number of virtual drives for restores in a DR situation! Again, this is all implemented in an environment where we are within fibre distances, so I haven't investigated the hardware needed to deal with your case. Wanda Prather "I/O, I/O, It's all about I/O" -(me) -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Paul Zarnowski Sent: Wednesday, December 21, 2005 12:01 PM To: [email protected] Subject: copy pool architecture question We are looking to implement a copy storage pool in a distant location (200 miles away). Network connectivity is good - 1Gb e/n to start with. DR site is not necessarily the same location as the copy storage site. We are considering the following options: 1. use of a remote TSM server and using virtual volumes, or 2. remotely attached tape library using iSCSI to tape drives, or 3. PTAM (pickup truck access method - moving tapes around) If anyone has experience with options 1 or 2 that they would care to share, I would appreciate it. Concerns that I have: Option 1: using copy tapes for DR would require both primary and remote servers to be relocated/recreated at DR site, instead of just the primary server. Option 2: would like to know if anyone else is doing this and with what h/w. Thanks in advance. ..Paul -- Paul Zarnowski Ph: 607-255-4757 Manager, Storage Systems Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801 Em: [EMAIL PROTECTED]
