Re: [BackupPC-users] Is there a speed setting?

[Les M. <les...@gm...>]

Jeremy Mann wrote:
> 
>> What operations are you watching to see these numbers?  The only one
>> where network bandwidth matters much is the initial copy of a new host.
>>     The rest of the time you are mostly doing comparisions.  Backuppc
>> will be slower than native rsync because it is in perl and because it is
>> working with a compressed copy for the comparison.  And perhaps you
>> didn't use the --ignore-times option on the runs you are using for
>> comparison.  Backuppc does this on fulls and it will slow things down to
>> the speed that the remote can read the whole disk for the checksum
>> comparisons - but it gives you an integrity check on your pooled copy.
> 
> I'm watching a live output of Ganglia showing network usage while the
> backups are going. Also simple math.. I just finished one full backup, 16
> GB in 143 minutes. That's simply unacceptable for a full backup.

You still haven't said whether this is the first run where the files are 
actually copied or not - if not you shouldn't expect much network 
activity.  How long would it take the target to read all it's files? 
Something like 'time tar -cf - / | cat >/dev/null' would be a reasonable 
test.  (Don't do -cf /dev/null with gnutar because it will cheat and not 
read the files.)  That would be the fastest an rsync run could possibly 
complete with the --ignore times option even if you don't transfer any 
data or create new files on the server.

> Now if you tell me my hardware isn't fast enough, the BackupPC server is a
> dual Opteron 2.2 Ghz with 8 GB RAM and 24 300GB drives in a 3ware RAID5
> array, it isn't.

Either end can limit the speed.  How many concurrent runs do you do? 
Also, you should expect much faster rates if you have a few large files 
than if you have millions of tiny ones.

-- 
   Les Mikesell
    les...@gm...