Holger Parplies wrote at about 20:16:49 +0200 on Tuesday, July 23, 2013: > Hi, > > Richard Shaw wrote on 2013-07-23 12:43:19 -0500 [Re: [BackupPC-users] Move > BackupPC "TopDir" To New Larger Hard Drive]: > > On Tue, Jul 23, 2013 at 11:39 AM, Holger Parplies <wb...@parplies.de> > > wrote: > > > > > Hi, > > > > > > backu...@kosowsky.org wrote on 2013-07-23 09:01:09 -0400 [Re: > > > [BackupPC-users] Move BackupPC "TopDir" To New Larger Hard Drive]: > > > > Aaron Cossey wrote at about 14:13:26 +0200 on Tuesday, July 23, 2013: > > > > > Sorry but all those pipes are going to slow the transfer > > > > > needlessly. > > > > > > > > While I too use SIGINFO, I doubt the extra pv pipe will slow anything > > > > down given that disk read/write is by FAR the rate limiting step... > > > > > > well, yes, but the pipes *do* mean data has to be copied around > > > needlessly, > > > which does come at *some* cost (possibly CPU load). > > > > > > My recommendation would be dd_rescue, which shows you progress, handles > > > read > > > errors, has a less error prone command line syntax ... > > > > I'm sure there are various opinions on this but I just replaced a hard disk > > in my desktop computer which used LVM and it made things REALLY easy and I > > didn't even have to reboot nor was the system ever unusable. > > > > If your old drive is not using LVM then you might want to consider it on > > the new drive. > > I fully agree, but pvmove only works if you are already using LVM, and if you > are, you're unlikely to ask this question in the first place ;-). > > You can migrate to LVM with 'dd' or 'dd_rescue' much in the same way you > would > transfer your data to a new partition (or whole disk) - your destination > would > simply be a LV. > > You can't use 'dd' or 'dd_rescue' or 'pvmove' if you want to change your FS > type or your FS doesn't support resizing (presuming there still are FSes that > don't ;-). If that's not the case, you probably shouldn't be copying at the > file level (rsync, cp, tar, BackupPC_tarPCcopy ...). The notable exception is > a *small* pool on a large disk, where a partition level copy will be slower. > You'll have to find out for yourself what "small" means, but it will have > something to do with "number of inodes" and "number of directory entries" > (i.e. links to inodes). If you run into problems, your pool is not "small". > > > [...] > > After that I grew the volume group to the full size (went from 500GB to 1TB > > drive) and then resize2fs. > > You mean the logical volume :). > > > One thing to keep in mind, though, when using pvmove: you still need to move > a > lot of data from one disk to another. During the time this takes, your data > may be spread over two disks, meaning a failure of any one of the disks could > lose all your data. This might not be relevant, because pvmove creates a > temporary mirror. I'm not sure whether it would mirror the whole LV in any > case or only a smaller portion (under some circumstances). If you are > replacing a disk that is failing, dd_rescue might be the better approach. If > you are just replacing a full disk which is otherwise ok, you are probably > fine with pvmove. > > Of course, losing your source disk before the end of a copy with > 'dd(_rescue)' > has the same problems. > > Regards, > Holger
I also have lost an entire BackupPC partition when resize2fs failed at a critical juncture... that is part of the reason that I now run 2 parallel BackupPC systems with the primary one doing daily incrementals/weekly fulls, and the secondary just doing weekly fulls... ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
