Skip to main content

Emergency Disk Recovery on Linux

While developing a script for Oracle Enterprise Manager (OEM) that checks the file system on our servers, I saw the /var on my (NIS) test VM was corrupt. No idea how it had happened but I decided to test my utils out.
In doing so, I ran e2fsck -n /dev/mapper/vgsystem-lvvar and it created a whole slew of error messages. Zero inodes, bad dates, orphaned inodes, etc. So I let e2fsck fix them using e2fsck -y /dev/mapper/vgsystem-lvvar... One of the things I saw run by me was "...erasing journal... device is now ext2" or something. <enter panic mode> thankfully Mandriva has a good Emergency Recovery section. It pointed me to some useful utilities.
If you have a bad superblock, try the switch for e2fsck -b 8193 first. There may be a perfectly good backup available. When you delete the ext3 journal, tune2fs -j device recreates it for you and rescuept can scan bad partitions for try to make sense of them...
Labels:

Comments

Post a Comment

Popular posts from this blog

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...
2 comments
Read more

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.
1 comment
Read more

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!
Post a Comment
Read more