Karel, if you set the copygroup option on a primary storage pool, this will mean that every single session that sends data to the server will need to have it's own mount point. This will increase the need for tape drives in your copy storagepool. Whats cheapest? Buying extra disk for disk security, or new tape drives just so you can bypass the RAID-security on your disks? You could create a storage pool for your most important server(s), so that not all sessions have a storage pool with the copypool option set. However, most of my customers with 200-300 servers have alot of important servers..... Which means, for them, they would still need alot of drives to handle the copygroup option.
I would still go for disk security, either by using RAID internally in your disk subsystem, or by remote mirroring between disk subsystems(which is getting more common as companies begin to look at disaster recovery options). It's alot cheaper than trying to bypass disk security by using the copygroup option. If your disk subsystems are on a SAN, you could easily mirror(remote or locally) them in the operating system, which would make it possible to raise the level of uptime, as the TSM server wouldnt go down if you lost a disk subsystem or a RAID array. Best Regards Daniel Sparrman ---------------------------------- Daniel Sparrman Exist i Stockholm AB Propellerv�gen 6B 183 62 T�BY V�xel: 08 - 754 98 00 Mobil: 070 - 399 27 51 "Bos, Karel" <[EMAIL PROTECTED]> Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> 2004-07-22 09:17 Please respond to "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> To [EMAIL PROTECTED] cc Subject Re: storage pool raid 1? Hi, Then again, if you configure these important server to directly write to a primary stg pool, with backupstg set to a copy pool, one backup will write to two destination at the same time. This will solve the raid 5 overhead and leave you with two copies of the "most" important data. Regards, Karel -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: woensdag 21 juli 2004 22:38 To: [EMAIL PROTECTED] Subject: Re: storage pool raid 1? ==> In article <[EMAIL PROTECTED]>, Daniel Sparrman <[EMAIL PROTECTED]> writes: > I've seen occasions when disks have failed on a TSM server, and a user calls > to have a single Word document retrieved. You want to be the one explaining > to the user that the disk on the backupserver has failed, and that his/hers > document cannot be restored? :=) "Me too." Additionally, there are increasing amounts of data stored on TSM which are not even "just backups". If you use the DB2 archive log transfer facilities, then between the time you run the log upload and the next time you complete a stgpool backup, your DASD has the only copy of that data in the universe. With a RAID-5 in place and a hot spare, I don't feel too much angst about this, but unmirrored would squick me for sure. We also use TSM as a data store for our content management application; That DASD is in fact the primary data. must must MUST be raided. - Allen S. Rout
