[ILUG] copy slow as hell ...

[Robert Sweetnam]

FRLinux wrote:
> Hello, I have a little NAS
> (http://www.komplett.ie/k/ki.aspx?sku=339804) of 2TB, a little hack
> (http://martin.hinner.info/mybook/) allowed me to enable SSH and NFS
> on the device (which is running Linux). the 2 x 1GB drives are set up
> as soft RAID 1 but performances are just plain wrong. I cannot sync at
> more than 500k/s which is far from the gigabit interface provided. I
> have tried a few hdparm commands but none of them worked so far. I was
> wondering if anyone came across this before :
>
> [root at MyBookWorld ~]# free
>              total       used       free     shared    buffers     cached
> Mem:         30032      26336       3696          0       2244       6276
>
> [root at MyBookWorld ~]# hdparm -tT /dev/sda
>
> /dev/sda:
>  Timing cached reads:   268 MB in  2.01 seconds = 133.22 MB/sec
>  Timing buffered disk reads:   56 MB in  3.07 seconds =  18.26 MB/sec
> [root at MyBookWorld ~]# hdparm /dev/sda
>
>   
Hi,

Your hdparm benchmark looks about what you should expect given the CPU 
in the NAS box.

For reference I benchmarked two machines here:

3Ghz Xeon SCSI RAID-0 gives:
Timing cached reads:   1582 MB in  2.00 seconds = 791.37 MB/sec
Timing buffered disk reads:   64 MB in  3.09 seconds =  20.71 MB/sec

And a 700Mhz PIII PATA UDMA 66 single disk gives:
Timing cached reads:   596 MB in  2.00 seconds = 297.98 MB/sec
Timing buffered disk reads:   72 MB in  3.01 seconds =  23.93 MB/sec

It looks as if the network settings for the NAS box might need to be 
tweaked a bit.

Cheers
Robert