What is vxfsd and why is it using so much CPU?

[mpaschali_1]

Greetings,

I am trying to do an Oracle import. I have an Aclass with 2 x 550MHZ processors running. I am trying to import 700,000 records into the database and so far it has taken me 7 hours to accomplish this. Now I know this isn't normal.

I ran top to see what the problem was and the number one process was vxfsd. What is it? What does it do? Is it important? and Why does it need to use so much CPU?

Help please

Thanks in advance

[Christopher McCray_1]

vxfsd is the daemon that controls your vxfs file systems and your logical volume manager, so it is pretty important. As for why it is using so much CPU, how much is it using? How much data in GB is it? Are the VGs you are importing to on the same controller?

Chris

[mpaschali_1]

Hi again,

It is currently using
"1 ? 32 root 152 20 0K 0K run 1:36 1.18 1.18 vxfsd".
Size of file I am trying to import is 800M.

Any ideas?

[eran maor]

Hi

At 10.20, VxFS had several threads that ran in a 1 by 1 thread model. The
threads are as follows:


DAEMON
------
vx_attrsync_thread
vx_delxwri_thread
vx_iflush_thread
vx_ifree_thread
vx_inactive_cache_thread
vx_inactive_thread
vx_logflush_thread
vx_sched_thread

With 11.0, the 1 by n thread model was implemented. So the daemon 'vxfsd'
combines all the above listed threads into one process.

about the cpu that he take it dep. on the amont of data that you import with the oracle .

it is normal if this process has high cpu if you are importing data to a vxfs file system .

[Christopher McCray_1]

from what you have shown, it doesn't look like vxfsd is using too much CPU. Have you looked at you oracle import log and see if there is something funny going on there? Where does your import prcess rank in "top"? What does your IDLE % look like?

[mpaschali_1]

Hi,

thanks for your response.
My problem is that the import is still going and has only accomplished 400,000 records or about 300M of the import file.

Is there any way I can help speed things up?

Without installing those patches right now?

[Christopher McCray_1]

I think you are at the mercy of time at this point because some of those patches you specify require a reboot, unless you know some kind of oracle trick to speed things up.

[eran maor]

Hi

no , there isnt online way to speed up the import .

it's also dep. of the disk array you are using .
i handel a case like this and the problem was with the autoraid of the computer was connected .

one last thing - it will be very nice if you can assin point to the pepole that is responsing you .

p.s - if you dont have the patches install them , if not for this issue but to the feutre

[mpaschali_1]

Hi Christopher,

in answer to your question it is the second on the list of processors. Here is a portion of top when run.

"Load averages: 0.65, 0.71, 0.75
98 processes: 96 sleeping, 2 running
Cpu states:
CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
0 0.62 1.4% 0.0% 0.8% 97.8% 0.0% 0.0% 0.0% 0.0%
1 0.68 0.0% 0.0% 0.8% 99.2% 0.0% 0.0% 0.0% 0.0%
--- ---- ----- ----- ----- ----- ----- ----- ----- -----
avg 0.65 0.6% 0.0% 0.8% 98.6% 0.0% 0.0% 0.0% 0.0%

Memory: 105920K (30164K) real, 286548K (29144K) virtual, 37204K free Page# 1/4

CPU TTY PID USERNAME PRI NI SIZE RES STATE TIME %WCPU %CPU COMMAND
0 ? 5687 mariap 156 20 31936K 2936K sleep 13:01 2.10 2.09 oracleHELPDESK
1 ? 32 root 152 20 0K 0K run 1:36 1.13 1.13 vxfsd"

My next question is why does the top process always say "sleep" and the vxfsd say "run".

[linuxfan]

Hi Maria,


From your top output, it doesn't look like the vxfsd is taking up too much CPU time.

Can you look in syslog.log or do a dmesg and see if you see any other errors?

Are you doing the import from a NFS mounted filesystem? I have seen cases where a misconfiguration of a lan card can cause excessive delays.Even copying a file can take a long time.

Btw are you running 11.0 or 11i?

-Ramesh

[Christopher McCray_1]

Well, your CPU is definately not being "used" at all, so I would definately take eran's suggestion with the patches. Also, it could be your disk hardware slowing you down as well (I am not sure what you have). If you Have an array, make sure your VGs have alternating primary paths. As for your last question, vxfsd is a kind of subsystem process that is constantly handling and monitoring requests by the OS, so it will always look like it is running. The Oracle process is an application which will grab processor time when it can, and top won't always catch it to display it as "run". i hope this helps.

Chris

[linuxfan]

Hi Maria,

If you have glance installed you can look at the oracle import process and see what is it doing or find out where its stuck.

Just another thought.

-regards
Ramesh

[Christopher McCray_1]

Both of your processors are over 97% idle, according to your output, so I would take a look at your import logs to see what is going on. I would like to also suggest you look at glance to check your disk performance. The syslog could also be a good place to look, and check the list of patches eran gave you against the installed patches on your server with swlist -l product |grep to see what you may need.
Chris

[Christopher McCray_1]

I didn't see anything in your syslog output to cause any alarm; your file system full message in dmesg is an old one (no worries). I am going to stick with the possibility that you have an I/O bottleneck somewhere. If you have glance (just type in glance at the command prompt) you can see what the overall percentages are. I think you will find that you disk percentage is very high, while your CPU % is low. Look into eran's patch suggestions and take a look at your disk setup. I have the same problems with my N-class servers where my db imports are 2-5 GB or more in size and I just dont have enough controllers to handle all the read/writes. I wish you luck as I need to break off now to do some housework.

Regards,
Chris

[mpaschali_1]

Thanks for all your help.

I will load the patches as soon as I can.
No I dont have Glance. Management thought it was the "Bells and Whistles" of HPUX.

Once again Thank-you all

[linuxfan]

Hi,

You can try installing the trial version of glance(runs for about 60 days). Its normally in the 2nd CD of the applications CDs


-Ramesh