From: Arno on
Here are some speed results I obtained with a
mixed HDD and SDD RAID1. I used a 3 disk setup,
but 2 disk should be comparable.

Setup: 3-way RAID1
HDD: 5400rpm 500GB/320GB notebook drives
(WDC WD5000BEVT, WDC WD3200BEVT, SAMSUNG HM320JI)
37GB partitions in the middle of the disks.
SDD: Corsair (Samsung) P64, one 37GB partition
Filesystem: ext3

Benchmarks:
- Opening a maildir in mutt with 1570 emails totalling 75MB
- Copying the same maildir onto the same filesystem
with following sync, i.e. "time (cp -r wagner/ ttt; sync )"

Before each run "sync; echo 3 > /proc/sys/vm/drop_caches"
to clear the chaches. Each measurement average of 3.

3 HDDs:
mutt: 12 sec (0.5 sec from cache)
cp: 19 sec

2 HDD + 1 SDD:
mutt: forgot to run it
cp: 14.7 sec

2 HDD + 1 SDD, HDDs removed and re-added with --write-mostly
mutt: 2.5 sec
cp: 4.1 sec

Yes, --write-mostly works. It needs removing and adding with this as
additional option for the HDD partitions (and waiting for the resync
on each), but the results are impressive and what I was looking for,
namely getting rid of the glacially slow mutt maildir open.

Arno

--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno(a)wagner.name
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans