[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Debian server for backups of Windows clients



Hi, David.

Thanks for your reply.

On 09/08/16 22:57, David Christensen wrote:

>> As you can see, the transfer was over than 3 GB and it were not hung. I
>> did several tests and all were without problems.
>>
>> I wonder if in the mentioned episodes of hangs you remember whether the
>> transferred volume was higher or lower than in this case (or it hung
>> randomly).

> Script it and run it every night for a week.  If it works every time,
> try again for 30 days.  Then 90.  Then 365.

Yes, I have to start testing on a daily basis. Anyway, the mentioned
test results were quite satisfactory.

>> As a side note, the larger file (disk01.img) took more than 40 minutes
>> to be transferred. So the rsync was running quite some time without
>> hanging. While it does not have to do with the topic of this thread, in
>> rsync progress data we can see that the average transfer rate was 10
>> Mbps. I guess it will have to do with that I'm going through a wireless
>> network. In this testing the Debian computer is a notebook connected to
>> the wireless router and the KVM Windows is on the wired network. May it
>> be so large the decrease in transfer speed? The wireless router is
>> TPLink WDR3600 with OpenWRT.

> My laptop has 802.11 a/b/g WiFi and Fast Ethernet.  Wireless data
> transfers are slow (~50 Mbps).  Wired is twice as fast (100 Mbps); still
> slow.  Newer WiFi (n, ac) should be faster, but only the newest WiFi
> hardware can match or beat Gigabit.

I think it is reasonable to expect that the wireless transfer rate is
lower than the one obtained in a wired network. But there is a big
difference compared to the ~50 Mpbs you mentioned. The peak obtained
with rsync was 10 Mbps. Maybe the best is to take a metric with iperf,
what do you think?

> For the initial full backup, I have found that scp is faster than rsync.

It is likely, since rsync adds control information used by rsync
algorithm to track the synchronization.

> When I know that I've added a bunch of new and/or large files on the
> sender, I sometimes try the rsync 'whole-file' option.  As I haven't
> benchmarked it, I don't know if/when it is helping.
>
> My biggest problem with rsync is when I reorganize file/ directory trees
> on my file server; especially big stuff -- raw video, movies, disk
> images, ISO images, etc..  I have yet to figure out an rsync incantation
> that does the corresponding moves on the destination, rather than
> mindlessly copying and deleting 100's of GB.  I have often considered
> writing an rsync prelude script for just this case.

If you make a move of files, but always within the same root filesystem
provided to rsync, you might want to consider using --delete for get an
identical image in the source and destination.


Kind regards,
Daniel

Attachment: signature.asc
Description: OpenPGP digital signature


Reply to: