Monday, May 7, 2007

Making Excalibur Work

I swear I spend 90% of my time trying to solve the same problems over and over again. I think I should be awarded the world record for the greatest number of Linux installs on a single system. The system in question is Excalibur, a Dell Precision 670N (The N says I didn't buy it with Windows). The most recent round of troubles happened as a result of downloading a huge chunk of file system data which caused the I/O performance to degrade. Who says Linux EXT3 is immune from fragmentation issues?

Anyway, I'm trying out XFS with LVM2 using a 3-Ware 8006 Escalade. I had one aborted install where XFS forgot that it was supposed to be a file system. I saw some interesting kernel "oops" messages that I've never seen before too. A good time was had by all.

The current configuration (mostly for my own posterity's sake) is the basic Dell 670 w/ 2GB of RAM, 2 300GB SATA HDD's and 1 74G SATA HDD. The two 300's are on the Escalade controller. Mirroring on that device was problematic (slow mirror performance and no dirty region logging), so I'm using striping and rolling the dice that I'll get to replace the machine before one of the drives drops dead.

I've reconfigured from the basic "one big file system" approach back to a more reasonable :
  • / = 16G
  • /var = 13G
  • /opt = 20G
  • /work = 200G
  • swap = 20G
I should add that when I restored some data, I flooded "/var" - why does MySQL default there anyway? One good thing with this setup:

# lvm
> lvextend -L+8G /dev/VolGroup00/var

Followed up by :
# xfs_growfs /var

Did the trick quite nicely. So, OK - I'm liking lvm and xfs better and better.

I found some good tips at : http://www.gagme.com/greg/linux/fc6-tips.php



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