Mark / Mike, Nice to here from you Mark. I am aware that DBSNAPSHOT can only be used for PIT restoration, at least after refreshing myself, and that only the BACKUP DB FULL/INCR resets the recovery log. What I'm now asking is can I make two DBB (full), one immediately after the other, and then use either one to do a restore to the point of failure using the recovery log?
Thanks, H. Milton Johnson Voice: (210) 677-6728 -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Mark D. Rodriguez Sent: Tuesday, February 17, 2004 10:23 AM To: [EMAIL PROTECTED] Subject: Re: Question on Restoration from DBSNAPSHOT Hi Milton, It's been a long time since we talked. You know you could have just called me and I would have helped you out. But anyway here is what I recommend: DBSNAPSHOT - should be used for your DR backups of the DB. They should be to a tape and taken offsite with your DR tapes. DBSNAPSHOT is effectively a full backup of the DB, but it does not involve the LOG in any way. Therefore, it can only be used for a PIT (point in time) restore. Also, please note that a DBSNAPSHOT does not reset the LOG like a DBB (full or incremental) does if the LOG is set to ROLLFORWARD. This makes it perfect for a DR type restore since in a disaster you would expect that the LOG would be lost. Please note if you are using DRM then you should update your scheduled Prepare command to include "Prepare Source=DBSnapshot" so that it manages the correct tapes for you. I sure do wish that the ITSM developers would make this the default! DBB(full and incremental) - should be kept onsite for rapid DB recovery including restore to the most recent time using a ROLLFORWARD log. I prefer to do these DBB to a device of type FILE. This allows for much faster backups and restores. Furthermore, I can schedule a full once a week and incrementals the rest of the week with no penalty on the restore time for multiple volumes since they are all coming from disk. This methodology offers a few more not so obvious advantages, you could easily schedule multiple DBB incrementals a day thus reducing the size requirement of you LOG. Also, if you use DEFine DBBackuptrigger you can set your triggered backups to go to the same device of type FILE which means in a triggered event your DBB will take place much faster and a rapidly growing DB would be less likely to trigger the DB spacetrigger. Remember when defining your DBBackuptrigger to make sure you specify NUMINCremental to 32 allowing for as many incrementals as possible between fulls, again there is no penalty here for multiple volumes since it is going to a device of type FILE. BTW, based on your note you were doing DBSNAPSHOT's daily which takes as much space as a DBB full does. If you switch to the method described above, you will use far less space on disk since you will be doing mostly incremental backups of the DB. If you are anyone else has any questions about this please feel free to contact me either by this list or send me email directly. -- Regards, Mark D. Rodriguez President MDR Consulting, Inc. ============================================================================ === MDR Consulting The very best in Technical Training and Consulting. IBM Advanced Business Partner SAIR Linux and GNU Authorized Center for Education IBM Certified Advanced Technical Expert, CATE AIX Support and Performance Tuning, RS6000 SP, TSM/ADSM and Linux Red Hat Certified Engineer, RHCE ============================================================================ === Johnson, Milton [IT] wrote: >All, > > TSM: Storage Management Server for AIX-RS/6000 - Version 4, >Release 2, Level 1.7 > OS: AIX 4.3.3 ML 9 >Log Mode: RollForward > (Upgrade project planned in near future, but that's another >story) > >Everyday I do a full backup of the database to 3590E tape, immediately >followed by a DBSNAPSHOT to a file on disk. The 3590E tape promptly >goes offsite. My question is if I experience a loss of the database >can I then restore from the DBSNAPSHOT and recover to the point of >failure using the RECOVERY LOG? I would like to avoid the time delay >of returning the 3590E tape, containing the database backup, from the vault. > >Anyone done this? > >Thanks, >H. Milton Johnson >UNIX Systems Administrator - USCC San Antonio, TX >Email: [EMAIL PROTECTED] > >
