Hi Richard! >The question is whether file type volumes do something like this also? >Can TSM open >directly to a desired file on a file type volume? Can't answer this one, I haven't been able to try it myself, but I know other (smaller) TSM shops do it. Guys? :-)
> VTL itself is a computer with a filesystem - doesn't it have the same > problem? If the > VTL appliance/head crashes would it not have to possibly fsck +100tb? I > may not > want to manage this directly on AIX, but the VTL has the same issue. Probably true, but I think that the chance of crashing a DL700 is much smaller than a crashing TSM server. We probably all encountered more than one TSM crash, especially when running 5.3.0.0... > If we use file devices we have to turn on client complression on all > servers. Currently, > we don't use client compression on most hosts, and get about a 1.5-to-1 > ratio from the > tape drives. We're not sure many/most of our Windows and Netware servers > have the power to perform client compression. We were also a little bit hesitant to enable client compression. You cannot predict the impact on CPU utilization and thus the impact on online applications running on the client. > 4) At the recent EMC technical conference at a presentation about their > CDL, they > recommended that colocation be TURNED OFF. They said that the speed of the > mounts and seeks made colocation unnecessary. I would assume this also > with > file devices, but it again depends upon the speed of seeking to a file in a > file type volume. Indeed, we will implement a non-collocated pool on the DL700. Because you do not use collocation, there will be less tapes in a filling state and a better volume utilization. You can define a volume size for the virtual LTO2 tapes, so we will start with a 50 GB. volume. A larger volume will waist space (with a reclaim percentage of 60%, the amount of expired data (40%) will be much larger) and the risk of volume contention during multiple restores will also be larger. > 5) We just met with our local IBM TSM expert (very good guy!) about some > things with > our environment, and this topic came up. Interestingly, he even > recommended possibly > using disk type devices for backup-to-disk. This was a big surprise! I > thought it was >mostly agreed that only file type devices should be used. Not true! A disk type storage pool doesn't allow you to reclaim aggregates, which will result in a heavily fragmented diskpool in time. Kindest regards, Eric van Loon KLM Royal Dutch Airlines ********************************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. **********************************************************************
