CIFS client poor performance

[Mihails Nikitins]

Hi,

Is it possible to tune CIFS/9000 Client (B8724AA A.01.06)performance? When I backup files via CIFS mountpoint, performance is really poor. I know the answer 'do not use CIFS mounts'. :-) Server is a dumb box, there is nothing to tune.

Points in advance for more ideas!

BR,
Mihails

[harry d brown jr]

What kind of server and OS level are you using as the CIFS server?

And of course the CIFS/9000 manual has some guidelines:
http://docs.hp.com/hpux/onlinedocs/B8725-90021/00/00/43-con.html


live free or die
harry

[Darren Prior]

Hi Mihails,

Yes, there are variables within CIFS client that can be tuned - there's a chapter in the manual referred to above on configuration variables. Some of the variables can be set on a per server basis.

Have you checked the log level? You might want to increase this temporarily in order to work out what's going on, but it should be set to a low level to avoid excessive logging.

You say that the "server is a dumb box", if it's one of these new-fangled appliance boxes you may be able to configure it to use something else such as NFS, which _might_ make a difference to performance.

regards,

Darren.

[Mihails Nikitins]

Hi,

Thanks for your feedback. The dumb network appliance does not support NFS and cannot be tuned.

I tried to switch on debugging
while doing backup session. I see that at the beginning the session scanned filesystem tree very slowly, then the writing process was a bit faster.

There were three type of messages in the log.

1. A lot of messages like

10/14 16:37:27.13 [2] srvUserForUid: Uid is 0


2. A lot of messages about founded filenames

10/14 16:37:56.96 [2]
nfsfhtable: found entry ->JSCRIPT<- (inum=10241)

3. A few messages like

10/14 16:40:33.32 [2] share \\hostname\sharename: total files=100, open files=0

Without clear understanding of the CIFS protocol it's hard to find a parameter to tune on the client.

Points in advance for more ideas!

BR,
Mihails

[Darren Prior]

Hi Mihails,

On the grounds that you are not seeing any errors in the log file I'd say that there's nothing critically wrong, it's just a matter of tuning.

Firstly, I'd check the networking side out - are the 2 devices (appliance and HPUX box ) on the same subnet?

If the filesystem scanning was slow then speeded up there might be some kind of caching issue - CIFS client has some tuneables for these related to timing and max number

Are you the only connection to the appliance? If no-one else is connected to it you could adjust some of the locking parms (you're only reading the files after all and not writing them, so it's fine if no-one else is attempting to change them.)

As for the CIFS, it uses MicroSoft's SMB protocol. There some documentation of the protocol at http://www.samba.org that may help your understanding of what's going on.

regards,

Darren.

[Mihails Nikitins]

Hi,

Thanks, Darren!
Answers to Darren's questions

1. Network connection between appliance and CIFS server is fine, they are on the same subnetwork.

2. While copying files, I do not lock the box (I cannot do it as it's mounted as 'read-only' for security reasons). The appliance is used as file box for few users, there are very few reads and writes. At night time performance (with no users) is the same.

3. I hope to find a success story from someone who has found a magic parameter in similar situation. :-) May be, HP internal knowledge bases contain such information.

BR,
Mihails

[John Dvorchak]

I did a little research on the subject and the best answer I can find is located here:

http://www.dd.iij4u.or.jp/~okuyamak/Documents/tuning.english.html

I have been fighting similar problems for a long time and never really got a good answer, but this seems to be the most promissing. I have not tried it yet, but I plan to work over my smb.conf file today and run some tests.

To make a long story short, in smb.con the [global] section add the following:

socket options = TCP_NODELAY SO_SNDBUFF=YYYY

where yyyy is a multiple of the mss closest to 8192 for example is the mss is 536 then 8192/536=15.2 so take 16 (15.2 rounded up) times the mss 8192 to end up with:
16*536=8576 and that is the yyyy number.

Good luck and let us know what you finally do come up with to increase performance.

[Darren Prior]

Hi Mihails,

Well it doesn't sound as if you are suffering from other users accessing the box at the same time as you.

I have had a look through our internal knowledge base and had no luck finding anything relevant, mostly the CIFS client documents are concerned with password and login type problems rather than performance related stuff.

I'm afraid I can't offer anything further - have you considered talking to the manufacturer of the appliance to see if they can help at all?

Other than that I think you may have to use some logic and then test out different permutations of the config settings.

regards,

Darren.

[Leif Halvarsson_2]

Hi
Do I understand you correct ?

This CIFS server is mounted on a HP-UX client and backed up from this.

Is it possible for you to mount this server on a Windows client and back up as a shared disk ?

[Joseph T. Wyckoff]

Test with an NT box as well, to see if you get similar performance.

HPUX is only half of the possible places solutions could reside...

Who is the manufacturer of your client?

Consider contacting the manufacturer of the CIFS client, and getting a firmware / software update?

It occurs to me the client may be deliberately tuned this way so that no one user can occupy the full bandwidth of the server...

[Mihails Nikitins]

Hi,

Thanks for the input. Some answers aren't rated yet since I should think more about its ideas.

Some answers to your questions.

- I use _HP_ CIFS/9000 client. Its Config file does not have config options like socket options = TCP_NODELAY SO_SNDBUFF=YYYY

- Using Windows share is always a solution but I wouldn't like to have Windows boxes in my environment.

Anyway, I'll be back if any new results are given to make knowledge base richer.

BR,
Mihails

[Mihails Nikitins]

Hi,

This is just summary of my results.

I could not find any good tunable parameters for HP CIFS Client. Playing with nfsSockRxBuf, nfsSockTxBuf, nfsTransferSize did not help.
I tried to change readAhed from
readAhead = {lock = 2; noLock = 0}
readAhead = {lock = 2; noLock = 2} and
got some improvement, but CIFS connection sometimes disappeared during intensive backup (I mount via CIFS as read-only, noLock=2 may be risky in this case).

Running parallel threads also did not help. I conclude that it's not possible to copy a lot of information from a slow box in minimal time. :-)

If full backup takes too much time, just divide CIFS mount in subtrees and run it in different days.

This is my another thread dealing with the case

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x1fefcdec06f1d61190050090279cd0f9,00.html

BR,
Mihail