[ILUG] copy slow as hell ...

[John Allen]

Robert Sweetnam wrote:
> 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.
>
Hmmmm, I get this on a AMD X2 4600+, with RAID6 (6x500G WD drives)

/dev/md4:
 Timing cached reads:   2300 MB in  2.00 seconds = 1150.91 MB/sec
 Timing buffered disk reads:  408 MB in  3.00 seconds = 135.95 MB/sec
> Cheers
> Robert


-- 
John Allen                          mailto:john.allen at codemountain.net
CodeMountain                        http://www.codemountain.net

Ubuntu 7.10, kernel 2.6.22-14-generic
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