On 4/08/2016 22:17, martin f krafft wrote: > Hello, > > the issue I've raised 4 years ago: > > https://sourceforge.net/p/backuppc/mailman/message/29727529/ > > still persists with BackupPC 3.3.0. Basically what happens is that > a combination of large new files and a slow connection between > backup server and client means that a full backup eventually times > out. Before that, it doesn't seem like data is being shoved across > the ether, so the ClientTimeout action seems legit. However, the > backup will be far from finished, and eventually be saved as > a partial. > > The next day, BackupPC awakes, tries to resume, and eventually times > out again. > > And then this happens every subsequent day. > > Instead, I'd expect BackupPC to keep growing the partial backup so > that it eventually becomes a full backup. > > I am using rsync+ssh. > > Here are relevant configuration items: > > $Conf{ClientTimeout} = 72000; > $Conf{PartialAgeMax} = 3; > > Any tips appreciated… > I forget the details but a couple of things that can help: 1) Ensure you enable SSH keepalives to keep your NAT firewall open 2) You can look to split remote files before the backup, and exclude the original large files (sometimes this is helpful anyway, because some of the chunks will not change, I do this with sql server dumps, ensure you don't compress them though, or else every chunk will 100% change). 3) Ensure that you can backup any file within the ClientTimeout, so if the largest file you will backup is 2.5GB, and you have a 2Mbps line (ie, 2M up at the client and 2M down at the server) then ClientTimeout will need to be 2500 * 8 / 2 = 10,000 seconds * 1.25 (never get 100%) = 12,500 seconds. You will need to calculate for your own maximum size file and bandwidth. I'd also suggest doubling this again to 25,000 in the example.
Remember, ClientTimeout is supposed to be a worst case scenario if the connection actually hangs. If your firewall/nat router/ssh will tear down the tunnel properly, causing rsync to fail, then you will never hit the ClientTimeout, so you can safely make this a much bigger number. The problem is backuppc will not accept a partial file, either the full file is received/saved in the partial backup, or none of the file is saved. I don't expect this will change. Regards, Adam ------------------------------------------------------------------------------ _______________________________________________ BackupPC-users mailing list [email protected] List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
