bottlenecks during qvm-backup

[lik...@gmx.de]

Hi,

is there a possibility to find the bottlenecks during a qvm-backup? A backup of ~100GB with compression takes several hours. During the time the (4) cpu cores (xentop) are not used well and the harddisk (iotop) is also idling a lot. I'm creating a backup to a usb attached ext3 formated harddrive.

How to find out which components are responsible for the slow process?

Best, Pete

[Mike Keehan]

Just try copying 100Gb to the usb connected drive to see how long that
takes. USB drive speed can be quite slow.

Mike.

[Chris Laprise]

Hi,

You may want to try my new incremental backup tool that works with Qubes:

https://github.com/tasket/sparsebak

Using LVM snapshot metadata, it finds the volume changes instantly
without having to read+hash the whole volume first. Its able to update
large 100GB+ volumes in under 10 sec. (i.e. its proportional to the
amount of changed data since the last backup) and testers say its pretty
stable even in pre-beta.

The 'new5' branch also has a new de-duplication feature that we're
testing to save even more bandwidth and disk space.

The only thing its lacking at this point is built-in encryption, so
you'll have to supply that yourself with an encrypted filesystem if you
desire it.

--

Chris Laprise, tas...@posteo.net
https://github.com/tasket
https://twitter.com/ttaskett
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