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Estimated time for a 20 GB backup

Posted by Anonymous 
Estimated time for a 20 GB backup
January 31, 2004 06:02PM
Hi. I'm new to the list and to rdiff-backup.

I got an 80 GB USB hard drive (it's really an IDE drive with a USB conversion
kit). Does rdiff-backup take a long time to run the first time, and should it
run faster for later runs? So far, it's done about 17GB over the last 6-8
hours.

I ran the command like this:

rdiff-backup --exclude /backup --exclude /proc --exclude /tmp --exclude /mnt
--exclude /dev --exclude /cdwriter --exclude /dos --exclude /mnt
--exclude /sys / /backup

Here's my disk usage:

# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda3 2.9G 113M 2.7G 4% /
/dev/vg/usr 10G 6.2G 3.9G 62% /usr
/dev/vg/usr_local 10G 4.8G 5.3G 48% /usr/local
/dev/vg/home 30G 26G 4.8G 85% /home
/dev/vg/opt 6.0G 4.4G 1.7G 73% /opt
/dev/vg/var 8.0G 5.9G 2.2G 73% /var
/dev/vg/tmp 3.0G 1007M 2.1G 33% /tmp
tmpfs 442M 0 442M 0% /dev/shm
/dev/hda1 99M 27M 67M 29% /boot
/dev/cdrom 655M 655M 0 100% /cdwriter
/dev/sda1 75G 17G 58G 23% /backup

Thanks!
--
Stephen
From here to there
and there to here,
funny things are everywhere. -- Dr Seuss
Estimated time for a 20 GB backup
January 31, 2004 09:16PM
Stephen Boulet wrote:
[quote]I got an 80 GB USB hard drive (it's really an IDE drive with a USB conversion
kit). Does rdiff-backup take a long time to run the first time, and should it
run faster for later runs? So far, it's done about 17GB over the last 6-8
hours.
[/quote]
is that 40Mbytes/sec?
thats probably about right for the drive+usb combo (usb2 i take it)
read the website - basically next time it runs it will only transfer the
changes and keep the old versions as reverse diffs. So yes - it will run
drastically faster the next time.
I have 18Gb odd backup sets that on an average day take 20mins or so for
rdiff-backup to finish.
thats over firewire

dave
Estimated time for a 20 GB backup
February 01, 2004 01:28AM
For the first time, is it faster just to do "cp -a data backup-dir" and then
run rdiff-backup with the "--force" option?

On Saturday 31 January 2004 11:15 pm, David Kempe wrote:
[quote]Stephen Boulet wrote:
[quote]I got an 80 GB USB hard drive (it's really an IDE drive with a USB
conversion kit). Does rdiff-backup take a long time to run the first
time, and should it run faster for later runs? So far, it's done about
17GB over the last 6-8 hours.
[/quote]
is that 40Mbytes/sec?
thats probably about right for the drive+usb combo (usb2 i take it)
read the website - basically next time it runs it will only transfer the
changes and keep the old versions as reverse diffs. So yes - it will run
drastically faster the next time.
I have 18Gb odd backup sets that on an average day take 20mins or so for
rdiff-backup to finish.
thats over firewire

dave
[/quote]
--
Stephen
From here to there
and there to here,
funny things are everywhere. -- Dr Seuss
Estimated time for a 20 GB backup
February 01, 2004 03:27AM
On Sun, 2004-02-01 at 09:25, Stephen Boulet wrote:
[quote]For the first time, is it faster just to do "cp -a data backup-dir" and then
run rdiff-backup with the "--force" option?

[/quote]It rather depends what your bottleneck is. If its CPU then yes, but in
your case it looks like it might be bandwidth on the USB bus, in which
case no.
I did do this myself, I backup a remote site using rdiff backup (they
also do a tape backup locally). The remote site has a 512k leased line
back to our office, so transferring the existing 20G of data was down
the link was A Bad Thing. I got them to send me a recent tape and
restored that to my backup machine, then ran rdiff-backup to sync the
two. Kinda reminds me of a useful piece of advice I once read, "Never
underestimate the bandwidth of a station wagon loaded with tapes".

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