Rsync and RAID storage specifications

[AZ 9901]

Le 4 août 2013 à 17:25, K S Braunsdorf a écrit :
> In message <B9CF2765-0BB7-4B0F-B758-1D5CF0219713 at gmail.com>, AZ 9901 writes:
>> Due to --link-dest, I have a huge read activity at the beginning of each
>> backup, and huge hard links creation activity.
>> I also plan to have several backups at the same time, coming from dozens
>> of servers.
> 
> Then the network will be the bottle-neck.  I would stagger the backups
> with some active management (not just stagger the start times).
> The easy thing to help would be --bwlimit=KBPS.
> 
> The disk tunes should be anything that is an even factor of the transfer
> size.  So 1 transfer (256k) might update 8 blocks, or 64.  This helps
> keep the VM system cache in check, otherwise you end up flushing blocks
> you will reference again to often.
> 
> Setting the transfer size to a large prime number is about the worst
> thing you can do, then set disk block size to a larger prime and
> see how bad "Bad" can be. :-(

KSB, thanks for your answer !
So I will test with chunks of 256K, 512K and 1024K.

Should I leave FS blocks to 4K, or increase them to let's say 256K ?

What about RAID type ?
I was thinking about the "common" RAID5.

Thx !

Ben