Arch Linux

Lone_Wolf

Forum Moderator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 11,958

Software Raid 5+0 or 6 ?

I'm thinking about setting up a big software raid system in a new pc.
The system will have atleast 4 Gb memory and probably an amd x2 +6000 proc.
(after the recent pricecuts the amd x2 6000+ gives better bang for buck than the intel c2d of the same price. Besides, i have very good experiences with amd systems and not-so-good with intel systems, mainly chipset problems)

Case : Lian Li PC-V2100B ( 7x 5,25 + 12x 3,5 bays )

It will be used as desktop with several vm's/fileserver/webserver, both reliability and speed are important.

I intend to use 10 sata ports  for hdd :
Onboard 2 ports + 8 on 2 Highpoint rocket raid 2300 pcie x1 cards.

the 2 onboard ports will get 2 WD 150 GB raptors for speed.
I plan to give the raptors 2 partitions each : root  10 Gb (Grub)   and the rest for a raid 0 array.
that means i'll have 10 Gb root + 280 Gb as md0 .

On the 2 raid cards i'll put 8 500 Gb disks, probably samsung spinpoint T166 .

With 8 disks i could make 2 sets of 4 in raid 5 and stripe those sets in a raid 0.

A stripe set of 2 raid 6 arrays takes to much space away , but an alternative would be to put all 8 disks in raid 6.
Both alternatives would result in a md1 of 3 TB.

md0 and md1 would then be combined into one big lvm setup with /opt, /var , /usr , /home.

What do you think would be the better choice for md1 : raid 5 + 0 or raid 6 ?

Last edited by Lone_Wolf (2007-07-20 21:47:42)

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

(A works at time B)  && (time C > time B ) ≠  (A works at time C)