SAMBA: Failed to verify incoming ticket

Solved an obscure error for some Windows 2003 R2 servers that were unable to map a drive to a SAMBA share. SAMBA is running on Oracle Enterprise Linux 4U6 with configs as defined by a wiki over at SAMBA. Error logs showed repeated "Failed to verify incoming ticket" errors.

Problem turned out to be related to Kerberos. Not so much the version or the encryption (MIT vs. Heimdal), as many sources mention, but to plain and simple time keeping! The Windows servers giving the errors were VMs running on ESX hosts. VMware Tools is supposed to do the time keeping and time sync the VMs to ESX, however that had slipped a bit too much. Kerberos accepts a maximum of 5 minutes. Ours was 9 minutes off...

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Tuning the nscd name cache daemon

I've been playing a bit with the nscd now and want to share some tips related to tuning the nscd.conf file. To see how the DNS cache is doing, use nscd -g. nscd configuration: 0 server debug level 26m 57s server runtime 5 current number of threads 32 maximum number of threads 0 number of times clients had to wait yes paranoia mode enabled 3600 restart internal passwd cache: no cache is enabled [other zero output removed] group cache: no cache is enabled [other zero output removed] hosts cache: yes cache is enabled yes cache is persistent yes cache is shared 211 suggested size 216064 total data pool size 1144 used data pool size 3600 seconds time to live for positive entries 20 seconds time to live for negative entries 66254 cache hi...

Preventing PuTTY timeouts

Just found a great tip to prevent timeouts of PuTTY sessions. I'm fine with timeouts by the host, but in our case the firewall kills sessions after 30 minutes of inactivity... When using PuTTY to ssh to your Linux/Unix servers, be sure to use the feature to send NULL packets to prevent a timeout. I've set it to once every 900 seconds, i.e. 15 minutes... See screenshot on the right.

Logbook and Note Book

I'm no longer actively working with Linux although I use it privately. This was my work logbook during my job as a Linux Engineer and Architect for KPN Data Centers. I'm keeping this as a log and note book. Who knows when it comes in handy although much will be outdated. If you find any good resources or more current howtos for what was written here, let me know!

Oracle: Unbreak my Linux Heart

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