[linux-lvm] Re: [SuperRescue] LVM support on Mandrake CD 1

[Brouard Nicolas <brouard ined fr>]

Hi,
I have had problem with my root partition which is often (twice) garbaged by e2fsck with dupplicated file names!
It may also affect the Logical Partitions (/usr, /var, /home, /tmp, swap) if someone says Y for e2fsck.  

So I wanted to have a backup of my root partition both as an additional logical volume and as a backup (250 Mb) on a host from my network.

Doing the backup partition on a host with dd made me angry because I spent time to mount root partition with NFS (see below) in order to suppress the "access denied".

But the main purpose of my search was to have a rescue disk with LVM loaded and ready to use. In a first step, I did not know how to do it with Mandrake CD 1 (rescue disk) and moved to Superrescue which has been described in Linux Planet as being able to do it (http://www.linuxplanet.com/linuxplanet/reports/4294/9/, article from Bill Von Hagen). But I did not found the lvm-mod modules neither the LVM programs. So I wrote the enclosed mail to the Super-Rescue mailing list.

Meanwhile I looked at some archives of the LVM mailing list and tried back to use the Mandrake CD 1.
This is the reason for I am sending this mail to the LVM mailing list too. It is a very Newbie message but I spend a lot of time to get the information.

Mandrake 9.1 allows you to directly setup a computer with LVM partitions instead of separated fixed partitions (just do Advance when partitioning or something like that) but the rescue mode is not documented in case of a problem like I got. 

Before entering Mandrake rescue details below, I also understood the advantage of the multiuser mode with the SuperRescue disk (I was asking the question). The advantage is that with this disk and a network, you can have a complete KDE environment with google access for example, only from the CD and without any mounted disk from your computer (So you can boot Linux from a Windows XP PC or whatever PC OS if you are invited somewhere without your laptop but only this CD!).

But back to the Mandrake 9.1 CD 1 (rescue). Here is how you can mount your LVM partitions or restore them if you have had problem.

- Boot from CD 1 Mandrake
- Type F1
- at boot: type rescue
  loqdkeys fr # For french keyboard only
  modprobe lvm-mod # it is on the CD (I haven't found it on the Superrescue disk).
  
- you must have access to vgscan and vgchange and their libraries. In my case my root partition
  is still an ext3 native partition (/dev/hda3 for example) and is working. So I only have to mount it.
  mkdir /mnt/root
  mount  -t ext3 /dev/hda3 /mnt/root

- then I can activate vgscan
  /mnt/root/sbin/vgscan
 and my Volume Group is recognized.
  /mnt/root/sbin/vgchange -ay
 and my Logical Volumes are recognized

Then I have to setup the network, mount the backup partition on a host and restore (or backup) the partition. 

Le mar 23/09/2003 à 13:19, Brouard Nicolas a écrit :
> Hello,
>
> I have seen on Linux Planet that Superrescue manages LVM (Logical Volume
> Manager) partitions. Standard Mandrake 9.1 rescue mode does not seem to
> manage them. But I have some problems (I am a newbie) with the rescue
> disk.
>
> My purpose is to save (and restore) partitions and mainly LVM partitions
> through the network.
>
> PART A 
>
> So I booted the rescue disk.
> I typed return to be in single mode.
>
>   loadkeys fr  # to get a French keyboard
>   mount # to verify that none of my disk were mounted!
>
> Then I setup the network with
>   ifconfig eth0 192.168.0.1 broadcast 192.168.0.255 netmask      
> 255.255.255.0
>   ping 192.168.0.2
>   mkdir /mnt/backup # To create a backup directory on RAM for mounting
>   mount -t nfs 192.168.0.2:/backup /mnt/backup 
>
>   dd if=/dev/hda5 of=/mnt/backup/rootpartbackup bs=10M # to backup my
> root partition
>
> Ok, it worked. There are probably better solutions, but I haven't found
> them. In order to allow root nfs on the host server I spent sometime to
> get it work. It seems that the /etc/hosts.allow should
> include one of these lines (or group of lines for portmap)
> #mountd: LOCAL
> #ALL: 192.168.
> #portmap: 192.168.0.11
> #portmap: 192.168.0.0/255.255.255.0
>
> File /etc/exports should be very explictit with the IP. 
> /backup  192.168.0.0/255.255.255.0(rw,no_root_squash,insecure,sync)
>
> Then exportfs -rv should be enough
> To unmount the backup either it can be suppressed from the exports file
> or
>   exportfs -u localhost:/backup
> otherwise it can be umounted.
>
> PART B
>
> Now I want to backup my LVM partitions
> but modprobe lvm-mod does not work
> and vgscan and vgchange -a y (which are the commands that I found in
> /etc/rc.d/rc.sysinit) do not work too.
>
> So I did a CTRL_D to get into multisuer mode. 
> Then I discovered that I could do an "ifup" to get the network.
>
> But here I am stuck because I cant find any LVM module or programs.
> What is the advantage of the multisuer mode? To get X or something like
> that. Sorry but I haven't found a Superrescue Basic Howto.
>
> Thanks a lot for any comment.
>
> Nicolas Brouard
> brouard ined fr
> Paris
>
>
> _______________________________________________
> SuperRescue mailing list
> SuperRescue zytor com
> http://www.zytor.com/mailman/listinfo/superrescue
> Please do not send private replies to mailing list traffic.