From: Miller, Anthony, A, Tech Dev, VF UK (Anthony.Miller@gb.vodafone.co.uk)
Date: Mon Nov 10 2003 - 05:59:28 EST
All...
I have a Solaris-8 F15K domain with 2 x JNI FCX2-6562 dual port adapters and
V5.3 of the JNI driver.
The JNI's are connected to brocade-3900 switches and are forced to 2Gb. An
XP512 disk array is also connected to this dedicated disk SAN. We have 120
LUNS (Open'E's) presented to each port of the first card (i.e.., 240 LUN's in
total). VxVm DMP is used and we can see these 2 x 120 LUNS down the alternate
paths on the second card.
The LUNs are under VxVm control, (V3.5) with VxFs V3.5 file systems on top.
We have done some file system tuning via the /etc/vx/tunefstab and set the
relevant mount points up with read_pref_io=64k,read_nstream=1.
I wont go into much detail but we are experiencing some disk write throughput
issues. This is under investigation but specifically the issue relates to a
dramatic throughput drop off in a highly parallel workload environment.
Shown below is the tail end of the JNI configuration file - for the last two
LUNs only:
jnic146x3-target0_lun118_hba="jnic146x3";
jnic146x3-target0_lun118_throttle=64;
jnic146x3-target0_lun119_hba="jnic146x3";
jnic146x3-target0_lun119_throttle=64;
Below is an extract of my /etc/system file:
* Allow SCSI transfers up to 8MB on VXVM layers
set vxio: vol_maxio=16384
: :
: :
*
* Required for XP512
*
set sd:sd_io_time=0x3c
set sd:sd_max_throttle=2
set maxphys=8388608
I have searched the archives and various other mailing lists. Several
articles refer to the /etc/system file entries as being the 'proffered' ones
with 'optimal performance'.
I have a specific question relating to the lun throttle settings (of 64 in
the JNI driver file) and its interaction with the sd_max_throttle setting of
2
in the /etc/system file. I checked the Solaris-8 kernel tunables guide but
couldn't find anything useful with regard to this.
Question 1 - do the LUN level throttle settings (in the JNI config file)
override those in
the /etc/system config file or vice versa? Or are they independent (i.e..,
the /etc/system file entries relating to the direct attach SCSI disks only).
Question 2 - Are these suitable throttle settings (for 120 luns per HBA port).
It has been suggested that values of 4-6 would be more appropriate (1024 for
an XP512 divided by 120 LUN's per port = 8.5)
Sorry to pose such vague questions, but your advice is appreciated.
Many thanaks and best regards
Tony Miller
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