[TriLUG] LVM2 on a new gentoo system

[Jon Carnes]

On Sun, 2004-03-14 at 11:53, Peter Long wrote:
> Hi all,
> 
> I am getting ready to try out a fresh install of gentoo. I want to use 
> LVM2. I have been reading through the LVM Howto for the last 45 minutes 
> and I am still a little confused. Can I setup my disks using LVM2 at 
> install time? Also, can the /boot filesytem be on LVM, or do I have to 
> set it up as a regular partition? I have one 30GB drive in this system 
> on /dev/hde. I suspect I will have to configure it as follows. If anyone 
> has a better suggestion please let me know.
> 
> /dev/hde1	/boot	~32M
> /dev/hde2	swap	1GB *	
> /dev/hde3       a LVM volume group, split into /,/home and maybe /var
> 
> * (I have 1GB of RAM, do I really need 2GB of swap?)
> 
> Is it possible to install /boot on a logical volume? I guess putting 
> swap on a LV does not make any sense (assuming it is possible).
> 
> This machine will be my linux play machine. I will be messing with it a 
> lot. It will not be expected to be VERY secure since it will be behind 
> my firewall/mail server machine. (Although I may want it to serve as a 
> backup firewall machine. Not sure yet.)
> 
> --
> Peter Long
> 
I haven't played with Gentoo much, but with other distributions you can
setup LVM during the install and even put /boot in the LVM.

My personal opinion is that it is a very bad idea to make /boot anything
but EXT2 (or EXT3 if it is supported natively in your kernel). On
systems where I'm using LVM, I generally setup /boot as its own
partition (150Mb to 200Mb, which is way overkill), and then the rest of
the drive gets setup as part of the LVM.

I have several production (client) machines setup this way, and the disk
I/O is really good on all partitions - better than running straight EXT2
partitions directly off the drives.  Of course the drives are all SCSI
on these production boxes.

I would guess that using the LVM for a /var ext2 partition (on a web
proxy or mail server) gives me an added 10% to 20% speed boost for disk
I/O.  Anyone have any hard stats on their installs?

Good Luck - Jon Carnes.