Re: best practice for lvm?

[Zhengquan Zhang <zhang.zhengquan@gmail.com>]

On Thu, Jun 04, 2009 at 09:58:59PM +1000, Alex Samad wrote:
> On Wed, Jun 03, 2009 at 10:53:52PM -0500, Zhengquan Zhang wrote:
> 
> [snip]
> 
> > > 
> > > My typical setup for a hd (the first 2 or 3 drives in the machine is
> > > 
> > > /boot 500M
> > > /     20G
> > > LVM or raid device
> > 
> > In that case, the first 2 or 3 drives have separate /boot and / but you
> > only use /boot and / on one of them?
> 
> no 
> 
> /dev/md0 => /dev/sda1 /dev/sdb1 /dev/sdc1 raid1 + spare => /boot
> /dev/md1 => /dev/sda2 /dev/sdb2 /dev/sdc2 raid1 + spare => /
> /dev/md2 => /dev/sda2 /dev/sdb2 /dev/sdc2 raid5 = pv => vg => lv's

Now I understand what you mean. So basically you do lvm on raid5 to get
a balance between storage space and redundancy.

> 
> 
> > 
> > > 
> > > I raid1 Partition on disk 1+2 and use disk 3 as hot spare. I do the same
> > > for partition 2
> > > 
> > > 
> > > for partition 3 I group together all the disk's in raid1 or raid5 or
> > > raid 6 and then allocate that to lvm and then make up swap /var/log/
> > > /home etc
> > 
> > Now I figured that your point is never use LVM over / . and LVM over
> > raid for other partitions. 
> 
> I try never to place / on a LVM 
> and to try and place LVM on some sort of raid

So you use LVM on raid to help you better cope with hard drive failures.

I understand now.

Thanks Alex!

-- 
Zhengquan