John Hudak wrote at about 12:06:29 -0500 on Saturday, February 13, 2010: > Hello: > I am considering using an external USB drive as the storage for my backups. > I am running backup pc under Debian 5.0. External USB drives are a *BAD* idea for multiple reasons: - Slow - Unreliable - Subject to being disconnected etc.
> Part 1 > What do I need to do to configure the USB disk as the target? (e.g. how do I > do it?) > The USB disk is currently formatted as a NTFS file system. Do I *need* to > reformat it to ext3? or other? - NTFS is not usually used - need to check whether it supports the types of hard links required for BackupPC > > Part 2 > Assume I am crazy paranoid about preserving backup data and I get a second > USB drive to serve as a backup to the first USB drive. > Also assume that I am not concerned about the bandwidth across the network > or the various buses. > > >From a data reliability standpoint, is it better to run a backup session to > USB drive 1, and then repeat the backup to USB drive 2? OR > run a backup session to USB drive 1, and then copy the backup directories to > USB drive 2??? Look at the archives and FAQ - this has been discussed *many* times so no point in wasting peoples time in rehashing. > The first approach could have errors in different backed up files on disk 1 > or 2 but given the odds, very unlikely that the same exact error would show > up > in the same exact way in the same file across both USB disks. > OTOH, the second approach would allow the exact error in the backup on USB > disk 1 to be copied to USB disk 2. > > I am leaning towards repeating the backup on two drives. > > My understanding is that files that are backed up (using either rsync or > smb) are 'encrypted' (for lack of a better word), and to view them I need to > use zcat.-True? There is a better word -- *compressed* > Also, can the backup profile be specified to perform complete data copies > periodically, as opposed to a baseline and then periodic incrementals? Read the documentation and FAQ. > Lastly, does anyone have a statistical number that represents the > probability of a backup file (e.g. on the target backup disk) containing an > error introduced > by the backup procedure? I know there are error probabilities for both disk > and tape reads/writes failures, but am wondering if anything like that > exists for the backup software. (A group I used to work with did this sort > of testing, and actually had some statistics on the reliability of backup > programs, wrt types of files, sizes, w/wo compression, and the types of > compression. Not sure the open source community would go through this type > of assessment - but thought I'd ask. The probability is either 0 if no bugs in the software (or your configuration of it) or 100% if bugs in the software and your dataset triggers the bug. Your question is not very well-framed and pretty meaningless. I suggest you learn a bit more about backup in general and backuppc in particular. There is a lot of good documentation on BackupPC in the Wikki and in the archives, I suggest you reference it... ------------------------------------------------------------------------------ SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev _______________________________________________ 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/
