[Sussex] Mixing SCSI, IDE and RAID with LVM

[Jon Fautley]

Mike wrote:

> Another point of note is whether you want to have /boot and / on LVM. 
> This is acceptable, but personally I don't trust it completely - i've 
> been bitten with LVM before, so I prefer to have them outside of it - 
> I'm sure others will disagree, and one day I hope my mind changes about it.

Don't put /boot on LVM. It'll not work. All your other advice is sound 
though.

FWIW, I run all my systems with LVM. I usually have a 'system' VG and a 
'data' VG (or for my virtual hosts, a 'vm' vg). This makes the 
human-readability of the filesystem layout much better.

I run this:

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/earl-data
                       1.8T 1009G  664G  61% /filer

and have not had a problem adding more disks and growing. It started out 
as a 240GB filesystem made up of 3 x 80GB disks. It's now got 3 x 500GB 
SATA disks, 1 x 400GB IDE, 1 x 250GB IDE and 1 x 300GB IDE. None of the 
original 80GB disks are in use (pvmove'd all the data away).

One thing to note - if you are going to be using pvmove and the like, 
make sure you've got plenty of RAM. That box has 256MB (of extremely 
expensive RAM, hence the lack of upgrade) and it will crap out when I 
start using pvmove to shuffle physical volumes around.

> I use ext3 on RHEL4/CentOS4, and reiserfs on Debian Sarge/Etch for the 
> filesystems - both can be grown reliably online (no need to unmount) 
> with 'ext2online' and 'resize_reiserfs' respectively.

You're concerned enough about your data to put the disks in a RAID 
setup, yet you use ReiserFS?

*snigger*

/j
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