Howto vmstat

[BRAGEUL]

Thanks Hein,

So i've got TYPICAL Value in oracle statistic and i will set to BASIC Value as soos as is possible because i don't use this fonctionnality. The device timedev is already created.

I read in a Oracle documentation that GH is only use on Alphaserver GS series and i've got DS20 and DS25 servers. Where can i set the max_ubc to mimimize the %memory use ? is there a specific sysconfigtab paramaters

I got this sysconfigtab parameters actually.
vm:
swapdevice = /dev/disk/dsk1a,/dev/disk/dsk1b,/dev/disk/dsk1g
vm-swap-eager = 1
vm_segmentation = 1

vm_ubcdirtypercent=10
vfs:
noadd_exec_access = 0

bufcache=1
fifo_do_adaptive=0
sec:
acl_mode = disable

ipc:
sem_msl = 100
sem_mni = 64
shm_mni=256
shm_seg=128
shm_max=2139095040
proc:
max_proc_per_user = 512
per_proc_stack_size=33554432
per_proc_data_size=201326592

I find this values in Oracle-Tru64's documentations and forum but i'm not sure that it was a good choice ..

Oups !!, I forgot to say that I had also 25 Progress 91D database in the same Oracle server ...

Didier.

[Hein van den Heuvel]

That's to 'typical' to have stats enabled to the max and then not look at the data. :-).
Try basic. If you can, collect (with the collect tool!) a before/after picture with a similar load? Mayb over a batch job?).

ubc:

sysconfig -q vm | grep ubc
ubc_minpercent = 10
ubc_maxpercent = 100

gh:

Equally valid for all Alpha's. But the GS series tend to have more memory and more user processes sharing that memory so the effect will be more dramatic.

big-pages: similar improvements to gh, more uses (code and data), easier to configure (just switch on). Be sure to get the latests patchkit (pk3) though because there have been problems with big-pages and earlier versions. Myself I used them find with no incidents for Oracle/Sap benchmarks, but I suppose you should give it a trial run if you can and doublecheck your backup situtation.

Hein.

[BRAGEUL]

Hi hein,

this is the value for
Myriam_Root >sysconfig -q vm | grep ubc
ubc_minpercent = 10
ubc_maxpercent = 100
ubc_borrowpercent = 20
vm_ubcpagesteal = 24
vm_ubcfilemaxdirtypages = 4294967295
vm_ubcdirtypercent = 10
ubc_maxdirtywrites = 5
ubc_maxdirtymetadata_pcnt = 70
ubc_kluster_cnt = 32
vm_ubcseqstartpercent = 50
vm_ubcseqpercent = 10
vm_ubcbuffers = 256
ubc_ffl = 1

If i understood, i must set
ubc_maxpercent to 20 instead of 100 ?

I got Tru64 5.1B PK2 in the first (DS25)
Tru64 5.1A PK5 on the second (DS20)

The kernel parameters and applications are the same in both servers.

I suppose that i can not use bigpage parameter without applyed the the lastest dupatch kit ?

Didier.

[Hein van den Heuvel]

> If i understood, i must set
ubc_maxpercent to 20 instead of 100 ?

I would recommend that as a first attempt.
This is based on our experience with Oracle testing. But as with all performance tuning 'it depends'. We actually go down to 2 or 4% for systems that clearly only do Oracle work, minimal fiel system activity.
The suggested 20% is 'middle-of-the-road'.
It is dynamic, so just try!


big-pages is a V5.1B feature, and should only be used in production with PK3 or later.

Hein.

[Antoine Morpain]

Before enabling bigpages you may apply the following early release patches:

9-V51BB22-E-20040427 - HP Tru64 UNIX V5.1B PK2 (BL22) ERP Kit:
VM-Related Fixes for V
Content type: Tru64 5.X patch document (ITRC Login Required)
OS: Tru64
Release date: Sunday May 9, 2004
http://your.hp.com/m/S.asp?HB13644154639X3500131X373163X

9-V51BB24-E-20040423 - HP Tru64 UNIX V5.1B PK3 (BL24) ERP Kit:
VM-Related Fixes for V
Content type: Tru64 5.X patch document (ITRC Login Required)
OS: Tru64
Release date: Sunday May 9, 2004
http://your.hp.com/m/S.asp?HB13644154639X3500133X373163X

[Ralf Puchner]

Also check with the Oracle tuning guide what values must be set. Ask Oracle for the documentation containing also formulas how to calculate each value and what type of memory model is best for your database.

Oracle can also give you the list of supported OS-versions and necessary patch kits tested (e.g. certified).