tune of vxfs filesystem

[S.S.]

Dear All,

$ uname -a
HP-UX B.11.11 U 9000/800

$ model
9000/800/rp3440

when i tried to create a dummy 1gb file it is taking morethan 1min.

Can we tune by using vxtunefs to reduce the time for the creation.

When i was creating a 1gb dummy file the I/O statistics are:

c2t1d0 12078 461.8 1.0
c2t0d0 12484 438.2 1.0
c2t1d0 19152 704.0 1.0
c2t0d0 18770 640.0 1.0
c2t1d0 19154 705.9 1.0
c2t0d0 19404 669.3 1.0
c2t1d0 19143 709.9 1.0
c2t0d0 18671 648.5 1.0
c2t1d0 20280 736.0 1.0
c2t0d0 20230 683.0 1.0
c2t1d0 18561 681.4 1.0
c2t0d0 18610 638.2 1.0
c2t1d0 18491 668.3 1.0
c2t0d0 18149 620.8 1.0
c2t1d0 17790 636.6 1.0
c2t0d0 17919 606.9 1.0
c2t1d0 18651 680.8 1.0
c2t0d0 18552 637.4 1.0
c2t1d0 16990 645.1 1.0
c2t0d0 16704 600.0 1.0
c2t1d0 11894 639.2 1.0
c2t0d0 11810 610.8 1.0
c2t1d0 18021 696.0 1.0
c2t0d0 17880 654.5 1.0
c2t1d0 13192 731.0 1.0
c2t0d0 13342 729.0 1.0
c2t1d0 16976 691.2 1.0
c2t0d0 16971 654.9 1.0
c2t1d0 7120 741.0 1.0
c2t0d0 6938 701.0 1.0
c2t1d0 16311 711.8 1.0
c2t0d0 16323 684.3 1.0
c2t1d0 16192 647.5 1.0
c2t0d0 16117 622.8 1.0
c2t1d0 14358 568.3 1.0
c2t0d0 14580 568.3 1.0
c2t1d0 11942 601.0 1.0
c2t0d0 12019 591.1 1.0
c2t1d0 10694 600.0 1.0
c2t0d0 10484 566.7 1.0
c2t1d0 12121 511.0 1.0
c2t0d0 12233 502.0 1.0
c2t1d0 15219 613.7 1.0
c2t0d0 15852 607.8 1.0
c2t1d0 14512 619.8 1.0
c2t0d0 13771 562.4 1.0
c2t1d0 13970 607.8 1.0
c2t0d0 14225 591.2 1.0
c2t1d0 11305 613.0 1.0
c2t0d0 11233 619.0 1.0
c2t1d0 8843 542.2 1.0
c2t0d0 8935 538.2 1.0
c2t1d0 9640 555.9 1.0
c2t0d0 9977 525.5 1.0
c2t1d0 11239 601.0 1.0
c2t0d0 11116 586.9 1.0
c2t1d0 10678 641.6 1.0
c2t0d0 10425 600.0 1.0
c2t1d0 11502 587.3 1.0
c2t0d0 11692 567.6 1.0
c2t1d0 12083 564.4 1.0
c2t0d0 12315 549.5 1.0
c2t1d0 13318 557.0 1.0
c2t0d0 13658 548.0 1.0
c2t1d0 11668 554.9 1.0
c2t0d0 11575 536.3 1.0
c2t1d0 11882 636.6 1.0
c2t0d0 11999 615.8 1.0
c2t1d0 12195 582.2 1.0
c2t0d0 12712 567.3 1.0
c2t1d0 11805 574.3 1.0
c2t0d0 12292 550.5 1.0
c2t1d0 11143 627.7 1.0
c2t0d0 12303 682.2 1.0
c2t1d0 9839 1097.0 1.0
c2t0d0 16066 1846.5 1.0
c2t1d0 9605 1224.5 1.0
c2t0d0 9752 1221.6 1.0
c2t1d0 11837 1480.8 1.0
c2t0d0 8435 1032.3 1.0
c2t1d0 8921 1142.2 1.0
c2t0d0 12407 1549.0 1.0
c2t1d0 9678 1233.7 1.0
c2t0d0 9575 1201.0 1.0
c2t1d0 9628 1230.4 1.0
c2t0d0 9760 1217.6 1.0

May i know the correct parameter to tune ?

[Johnson Punniyalingam]

http://docs.hp.com/en/B3929-90011/ch05s07.html

[Kapil Jha]

What command you using to make file?
which vxfs version and OJFS version.

BR,
Kapil+

[AVV]

Hi,

Can you please paste the output of

# vxtunefs

I hope it can be accomplished by changing write_pref_io parameter.

[Viktor Balogh]

did you use dd or prealloc command to allocate the disk space?

[S.S.]

Hi Ajesh,

Please find the output of vxtunefs for the /var.
# vxtunefs -p /var
Filesystem i/o parameters for /var
read_pref_io = 65536
read_nstream = 1
read_unit_io = 65536
write_pref_io = 65536
write_nstream = 1
write_unit_io = 65536
pref_strength = 10
buf_breakup_size = 131072
discovered_direct_iosz = 262144
max_direct_iosz = 1048576
default_indir_size = 8192
qio_cache_enable = 0
max_diskq = 1048576
initial_extent_size = 1
max_seqio_extent_size = 2048
max_buf_data_size = 8192

[Viktor Balogh · Accepted solution]

> Can we tune by using vxtunefs to reduce the time for the creation.

It's not 100% sure that the FS layer is what you need to finetune. What is your setup? Do you have Mirrordisk/UX? Is this fs residing on an LVM volume at all? Or do you have HW raid implemented?

I allocated 1Gig to our FS that has software RAID 1 on the LVM level and I got the same ~1 minute as result:

# time prealloc asdf $((1024*1024*1024))

real 1m10.06s
user 0m0.10s
sys 0m3.96s
#


Look inside this document to get the idea of performance tuning - the performance:

1) is relative
2) depends on several factors that you must consider when finetuning

http://h21007.www2.hp.com/portal/download/files/unprot/devresource/Docs/TechPapers/UXPerfCookBook.pdf

IMHO this is a very useful document that is also entertaining to read.