[mythtv-users] RAID suggestions?

Bruce McKenzie brucem at dynamicrange.com
Wed Nov 7 00:20:08 UTC 2007


On Thursday 25 October 2007 11:45:48 Nick F wrote:
<snip>
> I've been using RAID 5 for a year now with no problems.  I started with
> 3x750GB SATA2 drives, and expanded the array to now have 4x750GB drives.
> Disk throughput has never been an issue for me - serving multiple
> frontends, and I've never noticed any meaningful CPU draw (it is running
> with a C2D Intel chip).  My system disk is separate (as you are proposing).

One thing I don't hear in this discussion is the NAS aspect: how are they 
mounted?

My BE does an NFS mount of my file server dir.

My file server exports an 2.7T ext3 fs that is built on LVM which is composed 
of multiple RAID-5 volumes (two 3-disk and one 5-disk volumes).

The file server is a Pentium III-500 with 512M RAM.  All it does is serve 
files, and the CPU load is never that significant. However I am IO bound, 
especially during a array rebuild.

This is my third array; first was 4.6T Reiser3 on LVM on "raw" drives. It got 
massively corrupted to the point where I lost it all. I rebuilt on ext3 (on 
LVM on raw drives), and then decided to move to RAID-5. So far so good.

Except that it's slower than snot to delete things, and it loses ~9% capacity 
for fs overhead.

Is xfs or jfs safe over NFS? (I will not go back to Reiser; too burned) Last I 
checked xfs was not as stable as ext3...

Are there appropriate export/mount options? I currently use:

# fstab on file server:
/dev/VG01/LV01          /vault1         ext3    defaults,noatime

# /etc/exports:
/vault1 192.168.2.1/24(async,no_root_squash,rw,no_subtree_check)

# fstab on MythBE:
filer:/vault1 /mnt/vault1 nfs 
soft,intr,bg,tcp,rsize=32768,wsize=32768,nfsvers=3,actimeo=0

FWIW, I run gentoo (2.6.18-gentoo-r6)

-- 
Bruce J. McKenzie -- brucem at dynamicrange.com
Fullerton, CA


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