You are not logged in.
Hi,
I have a 180 GB hard drive and I backup it with backintime. The backup is saved to a Synology NAS mounted with NFS. I've manually tried to create an hardlink in the destination disk and I can see that hard links are supported.
The problem is that when I do a backup the amount of information transferred seems very big (60 GB) even when the amount of changes is very small (few GB). Backintime stays in the status "Take snapshot" where I guess it actually transfer data (after the phase of hardlinks creation) for many hours (5-6).
If I look at the log tough, it seems that the data transferred is only 2.30 GB in the following case. During the backup process the status was reporting "Sent data:" tens of GBs.
[I] Take snapshot (rsync: sent 2.30G bytes received 3.61M bytes 1.15M bytes/sec)
[I] Take snapshot (rsync: total size is 70.04G speedup is 30.47)
[I] Save config file ...
[I] Save permission ...How can I debug this behaviour?
Offline
I guess this is caused by the network overhead of NFS. Each and every filesystem action (get directory list, get file size and mtime, ...) will trigger a TCP request and an answer over NFS. This makes the whole process very slow.
It could also be possible that the mtime differs between local and remote so rsync has to calculate the checksum for lots of files. A workaround would be to add --modify-window=1 in 'Paste additional options to rsync' (Expert Options).
But you should rather switch over to mode SSH and not use NFS at all. Take a look at http://wiki.qedinux.be/index.php?title= … logy_DSM_5 for a good guide on how to use a Synology NAS with BIT.
Regards,
Germar
--
Disclaimer: I'm member of BIT-Dev Team
Offline
Thank you for the reply! That link seems exactly what I was looking for.
In the meanwhile I've found out that the problem is indeeed that BIT fails in creating hardlink. The problem seems to be related to the fact that the files on the NAS are created with user=nobody and then BIT has permission problems since it uses a different user.
I'll try to follow that instructions and see if I can solve.
Thanks again.
Offline