Backup recommendation
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From: Maurice Batey on 19 Dec 2008 11:29 On Fri, 19 Dec 2008 04:17:54 -0800, Ian wrote: > so > that I can easily pluck out files on another PC. I'd also like > something which has the sense not to copy thinks which are already > there. Rsync should fit the bill nicely. I use e.g.: mkdir /old /new mount -t auto /dev/hdb8 /old mount -t auto /dev/sda1 /new time rsync -avx --delete /old/ /new umount /old /new N.B. In the rsync line, the "/" on the end of "/old" is vital... The "--delete" is to ensure /old & /new are exact copies. Backing up / takes about 2 minutes (after the first time), and /home about 8 minutes (longer because /home has a 10GB VirtualBox virtual machine file). The backup drive is external USB, formatted ext3. Then picking out a directory or two to restore after some glitch is easy-peasy. Rsync is also handy for synchronising desktops and laptops (as is the more sophisticated Unison program). -- /\/\aurice (Retired in Surrey, UK) Linux Mandriva 2.6.27.5-desktop-2mnb 2009.0 32-bit KDE 3.5.10 Virtualbox 2.0.6 (Replace "nomail.afraid" by "bcs" to reply by email)
From: Gordon Henderson on 19 Dec 2008 11:46 In article <slrngknhtq.jhj.news06(a)desktop.tarcus.org.uk>, Ian Rawlings <news06(a)tarcus.org.uk> wrote: >On 2008-12-19, Gordon Henderson <gordon+usenet(a)drogon.net> wrote: > >> cp -al 01 00 >> rsync --stats -aHx --delete /path /backupdevice/00 >> >> So while not compressed, each day will only store what gets changed, > >Hard links (cp -al) are not copies, they're pointers to the same data, >so a corruption of that data knackers every one of your backups of >that file, so only of use to protect against accidental deletion. I know what a hard link is and what it does, and the difference between that an a symbolic link, and I've never said that backup up to the same server is anything other than accidental deletion prevention. I've been building servers with 2.5x the required disk space for the past 10 years using this method - I do it as part of my living, and even to just keep one days worth of backup, (using rsync) it's far easier to get files back off the disk than tape, and when working with monkeys who accidentally delete files on a daily basis, it's essential. The rsync + hand links is just one part of an overall strategy to manage backups and archives. So if this process is done on the same machine it is an accidental deletion recovery mechanism, but it will keep historical data too, as when the original changes, the rsync will delete the backup (leaving historical copies in-tact) and replace it in that days copy. So on day 1, the backup is a copy of each file (not a hard link to the files but a real copy). Day 2 makes a heirarchy of links to the copy then replaces files that have changed, and so on. So if you do edit a file in the archive area, then yes, it will corrupt all backups that are linked to that file, but not the original file. What you need to ensure is that you can't accidentally write to the backup area - I do this by keeping it mounted read-only most of the time, and copying it off to another server. I think the OP (or someone in this thread) was using removable USB drives? Gordon
From: Ian on 19 Dec 2008 12:38 On 19 Dec, 13:08, Ian Rawlings <new...(a)tarcus.org.uk> wrote: > On 2008-12-19, Ian <ian.gro...(a)btinternet.com> wrote: > > > Dear All, > > > I've just acquired a little HP Pocket Media Drive. I'd like to use it > > to backup /home, and I could do with some software recommendations. > > I'd rather not have the backups rolled up into a zip or tar file, so > > that I can easily pluck out files on another PC. I'd also like > > something which has the sense not to copy thinks which are already > > there. > > Well you can use rsync -av --delete /home/ /<media path/home-backup/ > to do it, but if the destination is a FAT partition or similar > non-unix format, you can lose permissions, owner details and some > files with certain characters in their filenames, e.g. files with ":" > in their filenames can't be written to FAT partitions and those > beginning with "." can also present problems. Thanks. That's more or less what I did: no --delete first time and I, as usual, forgot the trailing slash on the destination so created an extra and easily sortable layer. The drive formatted ext3 just fine, so permissions and names not a problem. It's a 120GB one and it cost £40 at Morgan, which seemed a pretty respectable deal. Ian
From: Ian on 19 Dec 2008 12:41 On 19 Dec, 12:17, Ian <ian.gro...(a)btinternet.com> wrote: > Would a simple cp -r --preserve=all --update /home /media/HP do the > trick sensibly? Or rsync -Rav /home /media/HP? > > Advice much appreciated. Thanks very much, people. The winner is rsync - done simply by hand this time, may automate it later. Ian
From: Ian Rawlings on 19 Dec 2008 12:57
On 2008-12-19, Gordon Henderson <gordon+usenet(a)drogon.net> wrote: > I know what a hard link is and what it does, and the difference > between that an a symbolic link, and I've never said that backup up > to the same server is anything other than accidental deletion > prevention. Certainly, but there are people taking hints from this thread so best watch ourselves ;-) -- Blast off and strike the evil Bydo empire! http://youtube.com/user/tarcus69 http://www.flickr.com/photos/tarcus/sets/ |