LVM Disk Striping vs Raid0

With the recent migration to Fedora 8, on my desktop I decided to put the root device onto a manually created striped lvm during Fedora's install with the default stripe size across the group of 2 partitions--one on each disk.

Today, I ran hdparm -tT on the striped volume, but was discouraged by the Timing buffered disk reads--they maxed out about 60MB/sec -- pretty much the same as a normal partition without any raid or lvm striping. I backed up the install, removed the lvms and stuck a Raid0 back on. After restoring the backup, I'm back to some nice speed reads:

/dev/md0:
Timing cached reads: 1222 MB in 2.00 seconds = 611.27 MB/sec
Timing buffered disk reads: 344 MB in 3.01 seconds = 114.25 MB/sec

It would seem that LVM striping is no substitute for software Raid0.

Cyrus mail server and Maildir conversion woes

Over the holiday break, I decided to switch from Ubuntu to Fedora Linux distribution. In part, because I'll be using RedHat at work now, and also it seems Fedora is a little more bleeding edge--more on that in a future post.

Anyway, Fedora uses Cyrus as the default imap server, so I installed it and read up to see what it offers over other mail servers. Seems popular enough and feature rich. The initial install was fine, but I then needed to convert my existing Maildir saved emails to Cyrus. While the format of the files is the same, the file names themselves are different.

After several attempts at various imap conversion tools to no avail--and I did not want to spend time making perl modules work and other various hacks--I tried my own little copy/rename script. This worked, however, when Thunderbird went to pull in the 2000+ emails, it completely jacked up the cpu load and continuously spawned multiple imapd processes every minute or so. I'm not sure if that was Thunderbird,Cyrus,or a residual effect of me doing raw copies of existing email files over. Several hours later and almost reverting to a Maildir compatible server ( dovecot is bundled with Fedora 8 too ), I found a simple solution.

I fired up Evolution and to my surprise, it supports direct Maildir folders in addition to imap/pop/etc. After registering a Maildir server and my Cyrus imap server, it was just a matter of drag and drop from Maildir to the Cyrus server--no other cludges or complex imap scripts needed.

I suppose the imap convert scripts ( mailutil, isync, etc ) serve a purpose, but it seems they are not without problems and several other hack scripts seem necessary to get them to work with a standalone Maildir folder.

Jumping On

Here I go. Jumping onto the blogger bandwagon.