Stephen, Thanks for the fast feedback! See below...
> I have a somewhat similar situation but have XP clients on workstations > and laptops to backup as well as some Linux servers. The tape unit is a > HP Dat 72x6. > > I am trying to get Migration to work - nearly there. Haven't looked into Migration yet. I'll check that out further. Thanks for the pointer! Upon first examination, it looks like migration will cause the data to be removed from the disk when it is put onto tape. I don't want it removed. I want it to stay on the disk so that I can restore from disk and not have to worry about bringing tapes in from off-site, swapping tape sets, etc. I'd like any restores to come from disk, not tape if possible. Can migration do this? I like the idea of migration, but only if I can keep the data I'm migrating and not delete it. The thought of backing up my backups seems strange, and would also make restoring from tape a much more difficult thing to do, since two steps would be involved. > I have one 300GB drive to hold the Volumes prior to migration that is > done twice a day one after the Laptops are backed up during the day and > one after the workstations and servers at night - I want the data on > tape in case the disc crashes. If I had another disc same size I would > mirror it and not migrate incremental backups to tape. Hmmm... I suppose it wouldn't hurt to backup the incrementals to tape just in case the backup drive fails. As an extra precaution, it would be good. I'm just not sure if I can get a weeks worth of full backups and incrementals onto six 20/40GB tapes. I think I can fit all the fulls on there. Assuming 8 servers with 30GB each, that is 240GB, but this is a maximum estimate. Six tapes with 20/40GB is 120GB/240GB. With compression working, it should be doable, or at least close. And I can add some exceptions to each server to trim down the total backed up if necessary. > I do Incrementals each day and Full backups once a week and have several > Jobdefs so I can spread the Full backup load over the week. Total Full > backup of all systems is 250+ GB. That's a good idea. Instead of backing up all full backups on a single night, spread the full backups out over the week. Nice tip! I alway hate how long it takes to do backups on the full backup day. So do you not do differentials at all? Wouldn't doing differentials save a lot of space instead of full backups each week? Or do you do it that way so your restores are faster or you don't have to swap as many tapes to do a restore? > > So, do you think I should back everything up to the disk, and then on > > a weekly basis backup the 500GB disk to the DAT40x6? Or somehow > > backup just the more recent backups to DAT on a weekly basis? Or do > > incremental tape backups of the 500GB disk every night? Or should I > > backup to tape from the original servers and backup to disk, instead > > of backing up to disk first, and then backing up the disk backups? > > I'm really not sure what approach is best. > > I would use migration for the Full backups and leave the incrementals on > disc if you are willing to take the risk - do the servers run some level > of Raid? Yes, all servers are running RAID1 mirrored drives. So does this mean that to do a restore, I would need both the tapes and disk available? The full would restore from tape, and the incrementals from disk? > > The idea is that I'd like to rotate between two sets of 6 tapes, with > > one set in the changer and one offsite. This is just in case of some > > sort of physical problem, like the building burning down. I realize > > the data could be up to a week old, but that is better than losing > > everything. > > I archive one set a month of Full backups and place it off site never to > be recycled. It has saved some person(s) from disaster. The cost of tape > is far less than the cost of the data. Yes, I agree. But I'm just doing web hosting, not corporate data management. My customers *should* have backups of their site, databases, and other data. And if they don't, I haven't at all given them the expectation that server backups go back more than a month. In fact, the hosting agreement states that we don't even guarrantee backups being available. Obviously, that's just a legal precaution and I'd really like to retain 3 months of data if possible. But that might have to shrink depending upon the actual storage requirements. > > Lastly, what about compression? I understand it is better to not use > > software compression on drives that do hardware compression > > themselves. The drive I have is supposed to do 20GB uncompressed and > > 40GB compressed. If I'm backing up to disk first, I want to compress > > it with software. But then if I backup those backup files to tape, > > what impact will the double encryption create? > > I do not use any compression and rely on the tape unit's built in > compression. Windows data files do not compress well (already > compressed) and I get about 40 to 50 GB per tape (native 36 GB). For > Linux maybe 60+ GB per tape. So you don't use compression when backing up to disk? Doesn't that mean it takes a lot more disk space? Or do you not do that because you know you are going to migrate all data to tape anyway? What exactly is the point of the way you do it? Why not just backup to tape from the start? Is it so that you have faster backups? The plan I was thinking about would have the disk store all the history data (say 3 months of backups). The tapes would only store the latest two weeks of data. The offsite tapes would have last weeks data, and the onsite tapes would have this weeks data. The tapes are only used for emergencies where the backup drive fails, or there is a fire, etc. > > Also, any idea why I seem to only get about 17-18GB of data per tape, > > even though each tape is supposed to hold as much as 40GB? I've tried > > turning software encryption on and off. Do I have to do something to > > tell the drive to use hardware encryption? > > I was getting file sizes of a max 17 GB on the 300 GB disc and then the > penny dropped - I had partitioned the hard disc with a small block size > of 1024 that I usually use on my Linux systems - I rebuilt the > partitions using the default block size of 4096. Some Full backups of > clients are 30+ GB. I'm not having file size issues of 17GB on disk. I'm talking about the data written to tape is about 17GB or 18GB. It seems like the tape drive isn't compressing the data. But if it isn't, why would it not get closer to 20GB? Or is there some sort of 2-3GB overhead incurred in the backup process? Thanks again for the help! I appreciate it. Tauren ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
