Hello Andreas, Am 25.03.2014 10:14, schrieb [email protected]: > > Zitat von [email protected]: > >> Hello, >> >> we have as of now daily incremental to disk and a weekly disaster backup to >> tape for about 20 >> machines with some 2TB of data. The backup to disk does one weekly full as >> basis and daily >> incrementals for the rest of the week, the disaster tape backup runs on >> weekend. We now like to >> replace the disaster to tape backup by virtual full backups derived from the >> disk backups. >> Therefore we need to know the following: >> >> 1.) What should we set as FileSet in the virtual? Does it need to be the >> same as in the original >> backup or does it matter at all?
The virtual full backup is technically a restore of the backups that are being consolidated. Therefore the jobids that are used for the virtual full backup also are used selecting the fileset (see sql_get.c, db_accurate_get_jobids()) So yes, you need to have the same fileset that you used before. >> 2.) What concurrency do we get if multiple virtual fulls are started >> concurrently? As of now we do >> data spooling with all jobs running concurrently, but i suspect for virtual >> full to tape the jobs >> will be running one by one, no? I think you already found out in your tests... >> 3.) Is it possible to run another backup to disk (one pool) while the >> virtual fulls are still >> running? As long as the volumes needed for both operations are not the same and you have two different devices that could work. >> 4.) Is a virtual full a fully usable independant backup or are there any >> special considerations >> like for migration/copy jobs? What do you mean with "special considerations like for migration/copy jobs"? The virtual full backup is not dependent on any other backup (like a "real" full backup also) >> Any other hints and tweaks are also welcome, because documentation about >> virtual full is somewhat >> short. >> > > Done some tests regarding 2. It shows that "concurrency" is 1 eg. only one > job accessing the tape > drive at once like expected. This is not a problem per se but the data rate > is low. We got around > 30MByte/sec to a tape drive doing 70..100MByte/sec with normal full :-( > As we can see with "iotop" the data rate reading from disk pool is well above > 100MByte so i wonder > why we don't get a decent data to tape speed? Is this expected or do i have > to do some tweaks? During virtualfull, all previous backups are consolidated which means that we have to copy the blocks from the previous backups but we only write the blocks that we still need. So more data is read than written. Also, if you are writing parallel jobs to your disks, the blocks of different jobs are intermixed, and have to be sorted out during the virtual backup. If your drive is not getting its minimum write speed, you should think about configuring spooling. best regards, Philipp -- Mit freundlichen Grüßen Philipp Storz [email protected] Bareos GmbH & Co. KG Phone: Phone: +49221630693-92 http://www.bareos.com Fax: +49221630693-10 Sitz der Gesellschaft: Köln | Amtsgericht Köln: HRA 29646 Geschäftsführer: Stephan Dühr, M. Außendorf, J. Steffens, P. Storz, M. v. Wieringen -- You received this message because you are subscribed to the Google Groups "bareos-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. For more options, visit https://groups.google.com/d/optout.
