We do not. I can say since moving to a JFS type filesystem, we've not had a problem even when the power was pulled on a couple occasions by loss of dual Entergy power feeds and simultaneous UPS rooms failing. And those times I have restored files (usually to an alternate location for comparison purposes), I've always been able to read the files I've needed without a problem. I was trying to not get into that discussion yet again... I was only speaking to the filesystem level and not the database. Using a snapshot results in no difference from a filesystem standpoint as breaking a mirror and mounting it under an alternate mountpoint to the backup itself. The difference is 1) I don't ever break a mirror 2) don't require a 3rd disk set (already run 26 spindles now, don't need to push it to 39) and 3) my setup/teardown times for backups decreased to seconds/a few minutes respectively and 4) I'm able to run 4 full system backups daily without the users ever noticing. But whatever your situation calls for at the database level as opposed to the filesystem is for you to decide. Your situation might be different but I've never had a problem getting data out of the backups.
>>> "Baakkonen, Rodney A (Rod) 46K" <[email protected]> 4/28/2010 >>> 1:14 PM >>> Do you do a dbpause at all during this snapshot process? -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Robert Porter Sent: Wednesday, April 28, 2010 1:09 PM To: U2 Users List Subject: Re: [U2] Universe and stripped drives Many 'nix systems not longer require breaking mirrors for backups... We haven't broken a mirror for backups since the late 90s. HP-UX and Linux for example. A MUCH better option is using logical volumes (and yes, you can still mirror and stripe) as well and use filesystem snapshots to backup. A snapshot takes what the filesystem looks like at the moment of creation and mounts it to another mount point. All writes occur to an alternate disk set, which any active application sees under the original mount point. When undoing the snapshot, all the writes are applied in order to the filesystem. The process of creating usually takes seconds, and if the users see it at all, it will appear as a slight pause. Undoing it depends on the volume of writes pending, usually seconds to minutes, but regardless will likely be MUCH less than rebuilding the mirror. And instead of needing a while 3rd set of drives, you only need enough space to hold the pending writes for the length of the backup. And they can live on the same set of drives of separate drives if you prefer. Robert F. Porter, MCSE, CCNA, ZCE Lead Sr. Programmer / Analyst Laboratory Information Services Ochsner Health System This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. >>> "Dave Laansma" <[email protected]> 4/28/2010 12:16 PM >>> My opinion is to stripe all your data over as many drives as possible. Regarding mirroring, I would suggest a third mirror. The third mirror can be broken anytime during the day and used for backup, then 're-sync'd.' This configuration provides for minimum data loss due to (the number one cause of data loss) disk failure. Drives are cheap. Mirror up! Sincerely, David Laansma IT Manager Hubbard Supply Co. Direct: 810-342-7143 Office: 810-234-8681 Fax: 810-234-6142 www.hubbardsupply.com "Delivering Products, Services and Innovative Solutions" -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of George Gallen Sent: Wednesday, April 28, 2010 12:47 PM To: U2 Users List Subject: [U2] Universe and stripped drives We are in the process of upgrading our system. When we setup our current system, it was suggested we strip our data drives (5) into one, instead of having 5 separate drives, so it could pull more data at once. The new system will have 6 drives available for striping We were going to have 6 drives striped into one, which would be partitioned into our data areas the thought being it would be faster disk access if it's pulling from all 6 drives at once. BUT...all of the partitions are on that one striped drive. Would it be better to have (2) sets of 3 drives striped into one, and setup the two most used accounts on each of those drives, so now it's only pulling data from 3 drives, but there could be less competition between the two accounts, since they are pulling from separate drives? Anyone played with this at all? FYI, each drive is mirrored as well, so if there is a drive failure, data loss is protected, if there was a drive failure on both the main and mirror (same drive) then with the 6 drive strip, we stand to potentially lose more data, than if there were 2 sets of 3 striped. But...since we have full daily backups, and potentially, considering a second backup during the day, the amount of data loss would be minimal....so I'm putting that off the table for now in determining whether to go with a 3 or 6 stripe. George Gallen Senior Programmer/Analyst Accounting/Data Division, EDI Administrator [email protected] ph:856.848.9005 Ext 220 The Wyanoke Group http://www.wyanokegroup.com _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users
