[CentOS] 4 X 500 gb drives - best software raid config for a backup server?

Sat Feb 21 15:42:34 UTC 2009
Chan Chung Hang Christopher <christopher.chan at bradbury.edu.hk>

> Would running two CP command to copy 2 different set of files to two
> different targets suffice as a basic two thread test?
>   
So long as you generate disk access through a file system and not hdparm.
> Is there a way to monitor actual disk transfers from command line without
> having to do manual timing?
Like I said: iostat

iostat -m 1
iostat -x 1
iostat -d 1
iostat -xm 1

Choose whatever information/data you fancy.


In fact, let me just post some iostat output to settle this once and for 
all. I shall risk the annoyance of all by attaching the output of a 
'iostat -m sda sdb md1 1' command.

This was generated by a single Linux client connected via cifs do a cp 
-r off the cifs remote share to local disk. The output was generated on 
the remote share box.

 From the output, I guess one loses grounds for claiming that md raid1 
only reads off one disk even if there are periods of time when it really 
does only read off one disk.
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