[Samba] Samba process throttled back?

Linda Walsh
Fri, 17 Jun 2011 21:49:34 -0000

Lang, Rich wrote:
> Hello,
>
> We are running Samba 3.0.33 on a 2-node Linux cluster running RedHat 5.6
ES.  Its primary application is to serve out a single network drive to support
our business (out 350GB in size).  For several years, this solution has been
running flawlessly.  File access was almost as fast as a local disk, so putting
files on the server was never a problem.  Our clients are running mostly Windows
XP Pro.  We have a few Windows 7 clients.
----
    Any difference in performance between the client types?

    Did the problems coincide with adding win7 machines to the network?

    Any new software on the clients (antivirus, firewall...etc?)  Is
something using up more memory on them?

    on your sockets, I up the SO_RCVBUF and SO_SNDBUF to at least 65536
each (more won't help until full smb2 support is in samba)....

    Did you get any new windows servers on your network around the time
of the problem?  I notice that you have your 'os level = 0', that means
for things like name resolution, your smb server will have lowest
  priority -- even below a win98 client, as I understand it.

    You mention you ran an 'strace -f' on smbd.   Have you looked at a
wireshark trace?  That would tell you more -- like when negotiating a
TCP session, if your windows client keeps reducing the RCV buffer size
that would have told you why the reads were getting smaller.  Maybe you
are getting packet drops, or similar -- Reminds me,  do you have
switches or hubs, what type of ethernet speed...I take it nothing in the
hardward on the clients or the server has changed?

    You say you are using RH.  Has the SW remained static since
installation and through this problem increase (I.e. an auto-update of
SW might have changed some setting in the kernel, or some firewall might
have been added, modified....etc...)...


    Are the windows client's 'paging' more?   I.e. was there any
change
in the VB script or the SW it's using such that now there could be a
memory leak, thus increased paging?

    Have you set/optimized your TCP/IP params on XP? (and what little
you can do on Win7...  which is less configurable than XP)....   Have
you added more clients (significant?)...


    On the Win clients...what SP are the XP clients running at?   Many
people complained when SP2 came out -- especially affected were network
applications.   SP3 has the best performance of the XP series (even
better than the original), while SP1 was slower than 'SP0' (original),
and SP2 was slower still...

    I don't have any specific theories...just asking for more data at
this point, since there are so many possible variables...and just having
the information out there would help anyone investigate the problem...



Good luck!....
Linda