Re: chekcpoints, BUFFER settings, and optimization
Jim -
How many Ultra Sparc CPU's (I'm assuming 6)?
How many Informix instances (I'm assuming 1) on the box?
Here's what I'd do:
Set Buffers to 100000 (~200 MBytes)
Set LRU_MAX_DIRTY=2
Set LRU_MIN_DIRTY=1
Then adjust buffers downward as necessary until you get the desired <2
second checkpoints. Check Read buffer hit ratio, > 95ish %, be happy.
set PHYSBUFF = 1024
set LOGBUFF = 1024
Monitor after a few days, and reset them so that the log pages per I/O
figure is 3/4 the (new) PHYSBUFF and LOGBUFF size (This is an SAP
guideline also, and it works pretty well...)
I'd also:
set RESIDENT=0 # don't tie solaris' hands unless you have to.
set NUMCPUVPS=6 # you cant do the work if the processes aren't
there
set RA_PAGES=32 # you got plenty of memory, use it.
set RA_THRESHOLD=30 # never make the CPU wait for memory
Adjust RA_ parms upward until RA-pgsused/(sum of x_RA) < 95ish % (from
onstat -p)
as for virtual segment size, run "onstat -g seg", count up the bytes and
reset your initial size to that + 10%. Monitor and reapply as
necessary. Additional segments on Sun wont hurt you though like it will
on HP & to a lesser extent, IBM/AIX.
BTW, 49 days is a while to be up, do you ever bounce the
machine/database?
You should also consider upgrading to 7.23.UCn, n>=3 ish, I gather
Informix is really concentrating on making this release stream fast and
rock solid.
Let me know how it turns out...with all the reads and seq scans you did
in 1 minute, this should help a *LOT*.
Greg
jneugebauer@ameritrade.com wrote:
>
snip......