Our setup:
Server: Windows Server 2008
Client: SHMZ 6.6 (FreePBX, CentOS)
mount.cifs version: 4.8.1
smbclient version: Version 3.6.23-14.el6_6Using this command to connect:
mount.cifs //192.168.0.10/Share /mnt/share -o "username=windowsuser,sec=ntlm,servern=SERVERNAME,password=windowsuserpassword"Takes 1 minute and 3 seconds to mount an empty folder.
Question is: how to speed up the mount process?
UPDATE 1: You may have noticed that I didn’t do any diagnosis prior to writing this post. Mainly it’s because I don’t know where to start. Please give me a at least a hint how to analyze the connection process.
UPDATE 2: Well, I captured the mount process, I see there 2 major lags: ~10 and ~30 seconds. Can’t figure out the reason though. Can you please suggest anything? http://tinypic.com/r/2cxz21z/9
Answer
This is the kind of problem where packet-tracing can be rather helpful.
tcpdump -s 0 -i eth0 -w mount-trace.pcap
Then perform your mount. Cancel the tcpdump once it is done. Then get the mount-trace.pcap file somewhere you can load into wireshark.
It will take some poking about, but mounting windows volumes that take a long time to finish is usually due to both sides of the conversation having trouble agreeing to a protocol to continue the conversation. If you take a look at the man-page for mount.cifs and look at the options for the sec= parameter you’re using, you can see how many of them there are.
What you’re looking for in wireshark are long gaps between parts of the conversation. That kind of thing can be an indicator of a timeout having to be expired before moving on to a failback method. CIFS is very well supported by Wireshark, and you can learn a lot about how Windows authentication works just by watching the various phases it goes through.
If that’s too scary, I suggest removing the sec=ntlm parameter from your mount-command and rely on the default, or setting it to ntlmssp. This has to do with NTLM being an old dialect of the Microsoft authentication protocol, replaced later by NTLMv2 and ultimately kerberos. Windows Server 2008 is coming on a decade old and sits in that inbetween space between when NTLM was firmly removed and was still allowed due to legacy reasons.
Unfortunately for everyone, legacy reasons includes really old CentOS versions. Like, Version 5 old.
Once you get it fast again, redo that tcpdump and compare with the first one. You’ll see the differences!
Attribution
Source : Link , Question Author : real_sm , Answer Author : sysadmin1138
