topic Re: 12H Perf. in Disk Enclosures

12H Perf.

Ash_4 — Sun, 09 Jun 2002 03:53:45 GMT

Hello Masters,
I have Oracle OLTP Application running on AutoRaid 12H. Following is the output of
# arraydsp -s 12
Array configuration:
Active Hot Spare Desired = ENABLED
Auto Include = ENABLED
Auto Rebuild = ENABLED
Rebuild Priority = HIGH
Capacity Depletion Threshold = 0%
Write Working Set Interval = 8640 seconds
Language = ENGLISH
Log Full Warning = DISABLED
Volume Set Partitioning = DISABLED
Format Pattern Fill = DISABLED
Subsystem Type ID = 12
LUN Creation Limit = 8
Maximum LUN Creation Limit = 8
Array SCSI configuration:
Controller X SCSI Address = 1
Controller Y SCSI Address = 0
Write Cache = ENABLED
Read Cache = DISABLED
SCSI Parity Checking = ENABLED
SDTR = ENABLED
WDTR = ENABLED
Terminator Power = ENABLED
Unit Attention = ENABLED
Disable Remote Reset = ENABLED
Secondary Controller Offline = DISABLED
Very Early Busy = DISABLED
Queue Full Threshold = 1952
Maximum Queue Full Threshold = 1952
Simplified Resiliency Setting = HighPerformance
Single Controller Warning = ENABLED
Lock Write Cache On = TRUE
Disable NVRAM on WCE False = FALSE
Disable NVRAM with One Ctrlr = TRUE
Disable NVRAM on UPS absent = FALSE
Force Unit Access Response = 0
Disable Read Hits = FALSE
Resiliency Threshold = 0.
Is any change is required to achieve the optimum performance.

Thanks in advance.

Re: 12H Perf.

Tobias Hartlieb_1 — Mon, 10 Jun 2002 05:39:55 GMT

Hi,

to my knowledge, there is not much to tune on this 12h. You have set already the "Simplified Resilency Setting" to "High Performance".
Free Disk space, however, is a major issue for Performance: The more spare disk space, the more data the array will store in Raid Level 0/1 (i.e. mirror) rather than in Raid level 5, which in turn is much better for performance.

Regards.

Tobias

HP Response Center Engineer

Re: 12H Perf.

Trevor Roddam_1 — Mon, 10 Jun 2002 22:51:42 GMT

Hello.

The 12H is very particular in regard to the Write Working Set and perf.
You have a 2.4Hr value. This means that there isn't enough space available for writes during the day.

With 12H's it is good to get this value higher to approx 12Hrs.
This means increasing the amount of free space. The only way to do this is to remove LUNs from the 12H. I would have a close look at the performance stats before doing this as there may be some fine tuning to bo done on the computers filesystems first.

Could you let us know:
The OS?
The Filesystem config? IE using striping etc.
Output from:
arraydsp -a [arrayid]
arraydsp -r [stime] [etime] [arrayid]
arraydsp -m [stime] [etime] [arrayid]
logprint -s [stime] -e [etime] -t perf [arrayid]

During normal work hours for a 10Hr period.

stime = start time
etime = end time
arrayid = The array ID

There may be some LVM tuning to be done.

Re: 12H Perf.

Ash_4 — Tue, 11 Jun 2002 13:42:53 GMT

Hello Trevor,
How Can I change the value ofWrite Working Set to 12Hrs. Pl explain.
Thanks.