[OpenAFS] Re: File creation delays

[Andrew Deason]

On Wed, 17 Mar 2010 15:10:49 -0400
"John W. Sopko Jr." <sopko@cs.unc.edu> wrote:

> Hmmm, 152.2.140.115 is my Windows 7 desktop, I use an ssh Secure CRT
> client to ssh from 152.2.140.115 to the various linux servers like
> 152.2.140.200. I am running the OpenAFS Windows client on my W7
> desktop and it seems to work fine, copy, create, delete files. So
> I assumed the firewall was open, I just did
> "rxdebug 152.2.140.115 7001 -version" from the file server and
> it hung. I will look into opening the firewall.

That will indeed cause problems.

> I would think that this would not matter since I am ssh'ing from my
> 152.2.140.115 W7 machine to linux clients and they are having the
> problem.  I just logged into my linux desktop 152.2.140.200 and did a
> mkdirt and got the delay problem, it is running openafs 1.4.12.

Yes, but 140.115 can still cause file writes to be slow, if it's having
network problems. What happens when you write to a file (or mkdir,
rmdir, unlink, any write operation), is that the fileserver must contact
any client with a 'callback' or 'callback promise' on that file, to let
the client know that someone has changed the file.

What happens here is that 140.115 has read that directory, and when
140.200 tries to write to that directory (via an rmdir or mkdir), the
fileserver tries to contact 140.115 to let it know that the directory
contents have changed. Since apparently 140.115 is blocking udp port
7001 requests, the fileserver hangs for a few seconds until the request
times out.

You may not notice slowness problems on 140.115, but I'd bet it may show
stale/incorrect data in AFS.

-- 
Andrew Deason
adeason@sinenomine.net