Hi Mark! Correct me if I'm wrong, but you are saying, well, if a backup is lost due to a disk failure, it's not a real problem, because you just tell TSM the volume is gone and the files will be backed up again during the next backup window. In that's so, you overlook the following cases: 1) What if some backups are not performed on a daily bases? The impact on missing a cycle is much bigger! 2) Missing backup pieces and correcting this in a TDP environment is a tricky task. For instance, when you are using RMAN in your Oracle shop, you will have a recovery catalog which is not in sync with TSM. It's not a very easy task to get them in sync again... Kindest regards, Eric van Loon KLM Royal Dutch Airlines
-----Original Message----- From: Stapleton, Mark [mailto:[EMAIL PROTECTED] Sent: Wednesday, July 21, 2004 15:40 To: [EMAIL PROTECTED] Subject: Re: storage pool raid 1? From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Daniel Sparrman >I'd say that depends on the level of security the organisation >requires. >If the disks would crash before migration, it would mean >you've just lost >all the backup data since yesterday night. Would you like to >go to your >boss and inform him about that and explain to him that you saved 300$ >worth of disk? True. However, this is an attempt to cover a double failure--the TSM client and the TSM server disk. The only time I've seen a double failure occur is during a complete system catastrophe--a server room fire, for example--in which case the only redundancy that will save you is a backup to tape that goes offsite. >Also, if you dont migrate every morning, the loss of data >could be alot bigger than just one nights backup. Also true. However, the only systems I've set up (or seen) that don't perform daily migrations to primary tape pools are disk farms that *never* migrate to tape; in these cases, I can certainly see RAID5 redundancy as necessary. In my experience, I see almost no case for fault tolerance in TSM-based disk systems that normally perform a daily migration to a tape-based primary storage pool. If a system crashing prior to migration worries you, perform your migration as early in the day as you can after clients finish running their backups to a cached disk pool. -- Mark Stapleton ********************************************************************** 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. **********************************************************************
