Holger Parplies wrote:

>>> specifically, write speed is less that half  
>>> that of a raid1 and way less than a raid0+1.
> 
> I would find interesting what kind of setup you get that sort of performance
> with (hardware or software RAID, disk speed, number of spindles, RAM size,
> $Conf{MaxBackups}, ...). I doubt it's an absolute figure as you make it sound.

I'd expect that to be fairly normal for short writes because the time is 
going to be consumed by the seek/read/write that is needed to fix up the 
parity for the rest of the block.

> And, is it really write speed you are measuring? BackupPC does a lot of pool
> *reads* for comparing transmitted files with pool content.

But a lot of the activity is updating the directories with new hardlinks 
which is not only a short write but an atomic operation for the 
directory that may block other operations.

-- 
   Les Mikesell
    lesmikesell AT gmail DOT com

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