Adam Goryachev wrote at about 14:14:49 +1000 on Tuesday, September 1, 2009: > Jeffrey J. Kosowsky wrote: > > Jim Leonard wrote at about 20:20:59 -0500 on Monday, August 31, 2009: > > > Jeffrey J. Kosowsky wrote: > > > > Is it self-evident that a BackupPC tree is difficult to > > > > copy/move/resize if not on a dedicated filesystem? > > > > > > What is a "dedicated filesystem"? How does it differ from any other > > > filesystem? > > > > I mean a filesystem used just for a BackupPC topdir vs. a filesystem > > that may contain data and/or code for multiple applications. Based > > upon the nearly weekly postings on this group, it seems that many > > people (myself included) initially set up their BackupPC topdir on a > > filesystem containing mixed data and without the advantage of things > > like LVM or ZFS since they don't realize in advance how hard it is to > > copy/move/resize the topdir area due to the large number of > > hard-links. It seems to me that new users should be strongly advised > > to create topdir on a separate ("dedicated") filesystem on top of LVM, > > ZFS, RAID, etc. to maximize flexibility. Alternatively, we can > > continue to address this same issue every week ;) > > BTW, my "simple" solution to this apparently "major" problem was as follows: > 1) Start using backuppc with a single FS (/) formatted with reiserfs (my > preference).
As I mentioned this is not (well) documented in the BackupPC documentation and continues to trip up new and not-so-new users alike. Also, there are use cases where you can't have a single FS for BackupPC (though Michael Stowe has decided to call them "fringe") > 2) Backuppc grows too big for the FS, and I want to add RAID1 backup of > the system > 3) Purchase and install 2 x 1TB HDD's and configure with a single > partition and use MD for RAID1 May be nothing for an enterprise but could be an issue for SOHO use. I for instance don't have two empty 1TB drives and enclosures hanging around. > 4) Boot from CD/USB live linux system, and use dd to copy the old > /dev/sda to /dev/md0 > 5) Adjust the /etc/fstab on the root FS to mount /dev/md0 onto > /var/lib/backuppc > 6) mount /dev/md0 somewhere > 7) mv var/lib/backuppc backuppc > 8) rm -rf all directories other than backuppc > 9) mv backuppc/* . > 10) rmdir backuppc > 11) umount md0 > 12) adjust the partition size > 13) adjust the filesystem size > 14) reboot and enjoy the newly expanded pool size > > I really don't see why people think this is so difficult... Sure, there > are lots of hardlinks, but block level copies are... simple. Sure, the > new drive is bigger, but increasing partition sizes and filesystem sizes > is simple. No "dangerous" operations, nothing technically hard or > difficult... just simple standard unix tools to solve a problem by > breaking it down into simple steps. Some of those operations can be dangerous. I have made mistakes when manipulating raid and filesystem sizes. But maybe I'm just sloppier than most ;) > > I don't use LVM, in fact I don't really know how to use it. It might > have made my life simpler if I had used it, but since I understand MD > much more than I understand LVM, I find it more reliable for me. The point is that playing around with mdadm, lvresize, resize2fs/resize_rieserfs etc. are not everyday operations for me and hence open to error - especially since the consequences of errors can wipe out a whole fs or even disk. I don't think there is anything wrong with expecting a program that is file-based to be copyable using standard file-based tools. Sure you can make a setup that avoids the problem by using dedicated filesystems and block-copying but that doesn't seem ideal or natural. Again, nobody said there weren't any solutions -- people just continue on a weekly basis to be dissatisfied with them.... ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ 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/