[linux-lvm] Building up a RAID5 LVM home server (long)
Erik Ohrnberger
erik at echohome.org
Wed Mar 2 03:27:29 UTC 2005
... SNIP ...
> >What if the I broke everything into 10 GB pieces, and
> created multiple
> >raid5 sets? Then I could LVM2 them together and have a large
> >filesystem that way.
> >
> >a=20GB, b=30GB, c=40GB
> >
> >a-1 + b-1 + c-1 = md0 (approx 30 GB storage)
> >a-2 + b-2 + c-2 = md1 (approx 30 GB storage)
> > b-3 + c-3 = md2 (waiting for one more drive)
> > c-4 = md3 (waiting for two more drives)
> >
> >
> This is sorta what I do. But in my opinion the gain of having RAID5
> (over RAID1) is when you get over 3 disks... at 3 disks you
> are burning
> 33% for redudnacy... 25% or 20% or 17% sounds better to me.
> I guess if
> you go too far it costs in calculating the parity.
Overhead: Yea, OK. Nothing is without a price.
I fooled around with various ideas, and came up with this for my
particulars:
(Note, rounded to nearest GB)
80 GB /dev/hda 60 GB /dev/hdb 40 GB /dev/hdc 45 GB
/dev/hdd
GB /dev/md0 (RAID0)
40 /dev/hdc
15 /dev/hda1
55
/dev/md1 (RAID0)
45 /dev/hdd
10 /dev/hda2
55
/dev/md2 (RAID5)
55 /dev/md0
55 /dev/md1
55 /dev/hda3
55 /dev/hdb
220
Yea, OK, so like the 220 is a bit optimistic, but should get pretty close to
that.
What do you think?
More information about the linux-lvm
mailing list