[linux-lvm] Implementation questions

[Jesus Manuel NAVARRO LOPEZ]

Hi, Colin:

Colin Coe wrote:

> Hi all
> 
> I need to set up a bunch of Linux machines of approximately the following
> specs:
> - PII 400
> - 2 x 20GB HDD
> - 256 MB  RAM
> - RedHat 7.2
> 
> What I want is to use software raid (mirroring) and LVM.  How do I do this
> from scratch?  I have looked but can't find a howto on this.  I have
> attempted to do this but have run into several problems:
> - During RH7.2 install you can choose to install to /dev/md but not LVM
> - Once you have installed the OS there is no (easy/intuitive) way to get the
> LVM in place
> 
> As I have about 130 of these to do, I am toying with the idea of installing
> a cut-down Linux system with XFS, LAM, md and ramdisk support and making a
> bootable CD-ROM which I can then use to configure the system how I want it.
> 


As you're talking about a farly respectable number of boxes, the 
automated idea seems reasonable.  I would have a look at the LUI project 
from IBM and/or even a physical disk replicator: the first option will 
be better with maintenance in mind, while the second one will be much 
faster.  Anyway, the problem about how to proficiently install 130 boxes 
is orthogonal with the LVM one.

As you say, you can set and install RH7.2 on top an md device, and no, 
RH7.2 installer has no support for LVM so, again due to the high number 
of boxes, I would try to go with something like this:
1/ Try to copy the install CDs to a hard disk (that is to a non 
read-only device).  Look for the RH7.2 install config list to reduce the 
number of packages for the "minimal" installation to a real bare 
minimum.  With this you should be able to reduce the amount of space 
requiered to something below 80/120MB over an md device.
2/ Install the system to a single root partition.  Most probably you 
don't want swap space neither under RAID nor LVM, so that partition will 
be created too.  It migth suppouse something like a 150MB root partition 
(for the whole install) and a 2*RAM swap partition, both as primaries.
3/ Have a newer kernel and patch as needed with LVM, and proper tools
4/ Make the LVM devices on top md mirroring as needed.  Then you should 
decide if you want root on LVM too or not (probably is easier not to 
have / on top of LVM, but that's your decision)
5/ Complete your installation, delete/actualize/add packages as needed, 
and move data to LVM controlled partitions (/usr, /var...)
6/ Mirror this "base" disk, running at the end of the process a 
"cleaning" script (even if you can manage your installation's net 
options through DHCP at least FQDN for that boxes should be fixed)
7/ Test and retest your procedures until you're glad with them
8/ Add to your process the way to remote maintain/actualize those boxes
9/ Polish the documentation you have been putting together till now and 
publish it somewhere as GPL so others can take advantage of your effort.

-- 
SALUD,
Jesús
***
jesus_navarro at promofinarsa.es
***