Re: [U2] UniVerse backups to disk
The snapshot disk space only needs to hold the amount of the changed data - not the whole filesystem. To the applications, it appears that a copy was made, but actually writes are being held behind the scenes. Don't think I'm explaining this well (Monday am), so lets try an example. Say that the UV DB is 10GB and it will take 1 hour to back it up. During 1 hour, only 1GB of data will be changed. The snapshot LV needs to be 1GB + a little for overhead - not 10GB. If you do a df while snapshot'ed it appears that 2 10GB partitions are mounted - the original and the snapshot. But the snapshot LV is actually only holding the pending writes. Unmounting the snapshot writes all the data (in order) to the real LV. While snapshot'ed the OS knows what's changed and what hasn't and UV never knows the difference. Robert F. Porter, MCSE, CCNA, ZCE, OCP-Java 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. >>> "jbut...@hampshire.edu" 8/20/2011 1:13 PM >>> We don't mirror but we use filesystem snapshotting for a clean backup with less than 10 seconds of downtime: ... Only cost in this is enough disk for snapshot. Jeff Butera Sent from my iPhone ___ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
Re: [U2] UniVerse backups to disk
People are still splitting mirrors? From what I can see AIX 5.2 (Oct 2002!) added JFS and snapshots. Removes the risk of a mirror getting merged back the wrong way if the break-backup-merge crashes and has to be undone by hand. Breaking the mirror means either you need to have multiple mirror copies or be at risk for a disk while split. We back up 3x a day for the production database alone. Add all the other filesystems and we'd have some mirror split more often than not. That's not an acceptable risk to me. Not when there are alternatives, and better ones at that. Plus it's a journalled file system... ever had the power yanked in the middle of the day? Or a panic? The fsck's alone can take hours on a large system. With JFS they take minutes. Still have to do the UV side, but my experience has been that the files will be MUCH cleaner. Pre-JFS a "unplanned" downtime took roughly 24 hours - post was less than 3. Robert F. Porter, MCSE, CCNA, ZCE, OCP-Java 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. >>> Wols Lists 8/19/2011 6:19 PM >>> On 18/08/11 05:07, Chris Lee wrote: ... As others have mentioned, you can pause the database. If you've got a mirror then DBPAUSE the database, break the mirror, and DBRESUME. You can now back up the broken mirror, safe in the knowledge that all the files are internally self-consistent. I think DBPAUSE guarantees the integrity of transactions, but if you backup both the /uv and the /uvaccounts directories, then you should get the transaction logs as well, I hope :-) ... ___ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
Re: [U2] UniVerse backups to disk
take a look at http://www.pulsarsystems.com/uvback.html -- Carl Dula Voice: 973-227-8440 X111 Pulsar Systems, Inc.Fax: 973-227-8440 271 US Highway 46, STE H209 email:c...@pulsarsystems.com Fairfield, NJ 07004-2474http://www.pulsarsystems.com ___ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
