[summary] md and ssd performance

Hi, fellows

Thanks to Brett Lymn, Ryan, Kevin Buterbaugh, Hichael Morton.
They suggested me to ignore the statistics for metadevices and 
concentrate  on the statistics for the physical disks. As long as 
they are ok, then you are ok. The high wait times on idle
partitions is really just an artifact of how the kernel measures
the wait times.  And also came the suggestion that download 
and install SEtoolkit, run "virtual_adrian" and let it tell you the story. 

thank you , everyone.

My original question is as follows:
Hi, all

I've got a SUN E450 running Solaris 7.

We used SUN Disksuite to combine two ssd disks to form a mirrored md disk.
The two ssd disks are : ssd0 ssd1
and the md disk divided into four partitions: md0 md4 md5 md6.

then the following is the output of  sar :

                   device   %busy   avque   r+w/s  blks/s  avwait   avserv
10:10:01   md0     0     0.0     0     1     100.6  77.2
           md4     1     0.0     0     2     191.5  59.0
           md5     97     6.1   164    2635  2.2    35.2
           md6     1     0.0     0     1     265.0  151.1
           ssd0    97     4.9   165    2641  0.0    29.4
           ssd1    96     4.4   165    2641  0.0    26.4

from the output , we noticed the response times of md0 - md4 are very high ,
up to 
400ms (avwait + avserv).  but from ssd0/ssd1's performance , it's below
30ms.
and also, most of the data is visiting md5, which with a not bad
performance, say 35.2ms.

The problem is , how to evaluate the i/o performance of this server ? is it
good or bad ?
any input/comment is appreciated.

sincerely 
likun
_______________________________________________
sunmanagers mailing list
sunmanagers@sunmanagers.org
http://www.sunmanagers.org/mailman/listinfo/sunmanagers