Good questions. The backups run concurrently, so the only waiting is on the max jobs parameter. But, yes, more than one job is written to the tape at the same time. This also keeps the data rate up and the tape drive busy, so even if one client slows down momentarily the drive won't have to stop, rewind the tape, and then restart. In my case, I'm using HP 960 drives, which slow down and speed up somewhat to meet the data rate. Plus, keeping the drive busy reduces wear-and-tear on the media and tape heads. I don't know if the other LTO drive models have this feature.
For restores, it *could* cause me to have to use more than one tape if files were created and then other files deleted between backups. But, for the most part this is a remote possibility. If I'm doing disaster recovery I'll probably use the later of the two (on site in my case) to start the restore, and then when the off site media arrives add what the local backups missed. If the local backups are lost due to catastrophe (fire, earthquake, whatever...) then they'll be glad to have anything, but the worst case will be a couple of hours of changes lost. If the loss happens near the end of the day they won't notice the difference between the two backups because 8 or 10 hours is already missing anyway. I run the off site backups first so that I have time to restart them and still have them finish in time to get off site. Then the on site backups run when the time crunch is over. I haven't had to recall an offsite tape for an "oops" restore, yet... HTH. On Thu, 2007-03-08 at 17:25 +1100, Nick Withers wrote: > On Wed, 07 Mar 2007 08:36:44 -0700 > Don MacArthur <[EMAIL PROTECTED]> wrote: > > > Nick, > > > > I use a similar approach with one significant difference and a few > > small ones. > > > > I have have periodic (daily and weekly) pools and write (in parallel > > jobs for all the clients) all the backups to one volume to save disk > > space and reduce the management complexity. > > I thought about having one big (well, bigger) volume for each day's > work, but am currently going with individual volumes for each host so > that each backup can be performed simultaneously. Have I missed > something here or would your parallel jobs not actually be parallel > due to each having to wait for the volume to become available? > > > This media goes off site. > > > > Then, I have a separate set of jobs at a lower priority, scheduled > > to run later, that write to another media for on site storage. > > This can be an SD resource on a local hard drive volume. I use a > > disk rack with a few TB, but anything with enough space will work. > > I have my volumes configured to limit the size of each (thanks to a > > post I saw from Kern) as they are used, and they get reused when > > the jobs expire. > > > > The priority thing keeps the second set of jobs from overlapping > > with the first set. I found that I got radically different > > (differential) results when both FD jobs were running on a client > > at the same time. I don't know how/why, but this seems to get me > > the results I want - two relatively similar copies of the same > > data. > > Wouldn't this create potential dramas with restores (assuming you're > using the same catalog for both jobs)? I mean, couldn't a restore > potentially demand both on-site and off-site volumes? > > > All my on site jobs expire after 2 weeks. Off site is kept for 4 > > weeks (daily) or 52 weeks (weekly). Of course, you'll adjust > > retention for your needs. > > > > FWIW. > > Thanks! > > > On Wed, 2007-03-07 at 22:40 +1100, Nick Withers wrote: > > > G'day guys, > > > > > > Just trying to design a backup solution using Bacula for a small > > > company I work for and would appreciate some help with a few > > > issues. This email may be rather long, so certainly appreciate > > > anyone taking the time to read it, let alone offer any insight > > > they may have! > > > > > > The main problem I'm having is that I want backups both on-site > > > (for restoring files users accidentally deleted and other > > > relatively trivial matters) and off-site (for when the site gets > > > stepped on by Godzilla). Methinks I'm after (upcoming?) "copy > > > job" magic... :-) > > > > > > The company currently has two 200-odd GB USB-accessible HDDs and > > > five 110-odd GB USB accessible HDDs. I'd like to avoid having to > > > acquire any further hardware at this point and think that this > > > should be enough to hold the required data anyway, at least > > > following the scheme outlined below. > > > > > > My current idea runs like this: > > > - A monthly full backup of each machine to one of the 200 GB > > > drives (each machine uses it's own full backup pool) > > > - This drive is then taken off-site and the other 200 GB drive > > > put in its place for the next monthly full backup > > > - Weekday night-run differential backups to one of the 110 GB > > > drives (each machine uses it's own differential backup pool) > > > - This drive is then taken off-site and the 110 GB drive for the > > > next differential backup is put in its place > > > > > > This would mean that with the just the full backup and the > > > previous day's differential backup drives from off-site, the > > > previous day's state could be completely restored. Bet I've > > > missed some really obviously nicer way of achieving this or > > > something similar though! I don't believe that too much data will > > > be changing on a daily basis, so hopefully the increasingly large > > > differential backups throughout the month won't be a problem. > > > > > > Now I also want to be able to access the backups on-site, without > > > having to drag in off-site backup drives. I'd prefer to do the > > > actual backup to the removable drives in the first instance as > > > these are the "critical" ones and I'd like the job(s) to fail in > > > the case of full removable drives. I've thought of: > > > - Copying the backup volumes from the removable drives to a > > > local location following a backup. Problems / potential problems: > > > - Have to know the names of the relevant volumes on the > > > removable media > > > - Would really like to be able to specify restoring from the > > > relocated volumes in a nice manner, rather than those on the > > > removable media > > > - Migrating the volumes from the removable media to a local > > > location following a backup. Problems / potential problems: > > > - Would want to be able to easily use the removable-drive > > > volumes if the local ones go AWOL (e.g., Godzilla...) > > > - Would want matching volume names on local and removable > > > locations so that volumes are easily identifiable > > > - Would want volume recycling to occur on both locations > > > > > > I've attached (slightly sanitised) Director and Software Director > > > config files for the current setup (very much alpha), in case this > > > helps. > > > > > > Anyone have any ideas? Should I just hang on until "copy job" > > > saves everything? Am I being profoundly stupid in one / many ways? > > > > > > By the way, the system's all-Windows and screaming along very > > > nicely using 2.0.2 - huzzah! > > > > > > Any and all thoughts appreciated! > > > ------------------------------------------------------------------------- > > > Take Surveys. Earn Cash. Influence the Future of IT > > > Join SourceForge.net's Techsay panel and you'll get the chance to > > > share your opinions on IT & business topics through brief > > > surveys-and earn cash > > > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > > > _______________________________________________ Bacula-users > > > mailing list Bacula-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/bacula-users > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
