From: Jason.Shatzkamer@cexp.com
Date: Tue May 20 2003 - 11:10:49 EDT
Hey All,
I am planning a volume reconfiguration for this weekend, and I figured I
would relate my plan to the list, and see if anyone had any insights, or
warnings.....
Currently, I have a Sun Fire 4800 connected to 2 T3 disk arrays...the arrays
are set up as partner pairs....each array is set up as a single LUN, as RAID
5, using 8 disks, and the ninth disk is configured as a hot
spare....further, I am using Veritas to mirror the arrays across
controllers....Solaris sees each array as a single large volume....
The server is a database server, and during periods of peak activity I see
IO wait ranging anywhere from 60-90 percent....my thought on this is that
since the T3's are only configured as single LUNs at RAID 5, then each
database read/write has to use all 8 available heads since the data is
striped across all 8 disks....further, that means that, in effect, only 1
read/write can occur at a time (discounting write-behind)....
I figure that if I reformat the T3's with 2 LUNs each, 4 disks in each LUN,
with the ninth disk in each being a global hot spare for each array, and
then distribute my database files across the 2 new LUN's/Volumes, then even
though each read/write will only use 4 heads instead of 8, at least I will
get parallel reads and writes, since each LUN can be reading/writing
simultaneoulsy...in my head, at least, I have convinced myself that there is
validity to this :-)
After the T3 formatting, I plan on continuing to use Veritas to mirror each
4 disk LUN across controllers to it's partner 4 disk LUN.....Solaris will
then see 4 volumes, instead of 2.....
My history with Sun/Veritas has been primarily new installs, and I am a bit
hesitant to embark on this reconfig without some insight from the
list....what steps do I need to take to make sure that Veritas doesn't freak
out when I bring Solaris back up, since the disk config will be completely
different from what Veritas currently expects in it's configuration
database....Do I do anything to Veritas before I start the T3 changes, aside
from breaking the existing mirror? Do I remove all Veritas configuration
through the gui PRIOR to formatting the T3's? Or do I wait until the T3
formatting is done, and then bring up Solaris, and repair the Veritas
config?
My current plan is:
Back Up Data to Tape
Break Existing Veritas Mirror
Clear Existing Veritas Config and Volumes
Touch /reconfigure to force reconfig after reboot
Shut down Sun Fire completely
Update T3 firmware
Format T3 disk arrays via telnet
2 LUNs each
4 disks in each LUN
1 GHS per T3
Bring Solaris to OBP
Probe-all to reconfigure devices
boot
[** Note that this is where I expect trouble **]
Use Veritas GUI to reconfigure new volumes
If anyone has any insght/advice, I would appreciate it greatly...FYI,
Solaris 8 fully patched, Veritas VM 3.2, VxFS 3.4.....
Thanks In Advance,....J.~
Jason Shatzkamer, MCSE, SSA
Corporate Express Imaging
1096 E Newport Center Drive
Suite # 300
Deerfield Beach, FL 33442
(800) 828-9949 x5558
(954) 379-5558
Jason.Shatzkamer@cexp.com
http://imaging.cexp.com <http://imaging.cexp.com>
_______________________________________________
sunmanagers mailing list
sunmanagers@sunmanagers.org
http://www.sunmanagers.org/mailman/listinfo/sunmanagers
This archive was generated by hypermail 2.1.7 : Wed Apr 09 2008 - 23:26:26 EDT