why so difference of sar output

[常有慈悲心]

Hi,all:

I have two site and two same server. every sever run the same kind of applicaion, but developed by the different team. Two server connect the two different XP512. The XP512's configuraion and firmware is the same. The first the blks/s and r+w/s larger than the second. but the first server avwait & avserv is smaller than the second. Someone said that the difference of Lvm layout is the cause,but why the first server is more busy and the time of avwait and avserv is smaller? I think the first server may have the better application, But I can't understand why the first site XP512 so busy and so small avwait and avserv.

[Stefan Farrelly]

Your sar output is far too small to be able to say for sure one is faster than the other.

You need to run sar for a lot lot longer, and at the same time check how many users are on, what they are doing etc. Its not a goot tool to compare like this. You need something more advanced like measureware/glance.

Perhaps the first thing to check is the lvm layout - to ensure both are same. For this you need detailed vgdisplay -v output, pvdisplay and lvdisplay output.

[Michael Steele_2]

Begin with your I/O configuration since 'avwait' and 'avserv' are metrics of I/O and when used in conjunction with '%busy' under 'sar -d # #' for example, they can help indicate an I/O bottleneck.

To evaluate your I/O into the XP512 begin with your HBA's / Fibre Channels and their patch levels and load balancing, which is done with 'swlist', 'fcmsutil' and LVM striping or autopath. For example on HP-UX 11.00 with A5158A's HBA's :

A) s700_800 11.00 Fibre Channel Mass Storage Driver Patch PHKL_23939
Notes: PHKL_28004
s700_800 11.00 N4000 42.06 firmware patch PHSS_26533
Notes: PHSS_26533
s700_800 11.00 Tachyon TL Fibre Channel Driver Patch PHSS_26798
Notes: PHSS_26798

B) fcmsutil /dev/td# state

C) If stripping is used check the stripe size which should be 32 or 64 kb.

lvdisplay -v /dev/vg##/lvol#
(* Note 'stripe size' *)

D) For LVM use 'pvdisplay -v' and note the logical volumes that reside on each LUN.