topic Re: Linux Bare Metal Restore to different type server in Operating System - Linux

Linux Bare Metal Restore to different type server

Emir Faisal — Thu, 24 Nov 2005 19:39:48 GMT

Hi,
Using mkCDrec, i'm able to restore a complete linux system (baremetal) to different server. The backup source is Redhat 2.1AS on Compaq Proliant ML370 G3, and restored to brand new Compaq Proliant ML370 G4.

The problem is, after the restore, the boot process in the new server (ML370 G4) hangs (attached). I suspect that there are modules that don't get loaded during boot, on the new machine.

1. My question is, what modules needed by ML370 G4 to be loaded during initial boot-up?

2. what file I should edit if I move linux installation from ML370 G3 to ML370 G4?

Thanks,
EF

Re: Linux Bare Metal Restore to different type server

Steven E. Protter — Fri, 25 Nov 2005 04:48:51 GMT

Shalom Emir,

I don't think this is an edit issue. The hardware configuration of the two servers is different. Different drivers are required to boot the hard disk.

Your method for server replication is not going to be good enough.

I would suggest trying another product that is designed for Linux and might work better. http://www.mondorescue.org

SEP

Re: Linux Bare Metal Restore to different type server

Andrew Cowan — Sat, 26 Nov 2005 09:49:47 GMT

Emir,

I don't think that even Mondo can help you here because it will still only restore the drivers that existed on the original server. Try cloning, then when the server is still unbootable, Run an install/upgrade from the original Redhat CD's, and this may install the devices you need. If not you will have to build the new server from scratch, and then manually transfer the files you have changed.

Another long shot, though not recomended is to build the new server from scratch, back-it up, restore the other systems image, boot "rescue" from the OS CD, and then restore the new backup over the top.

Re: Linux Bare Metal Restore to different type server

Emir Faisal — Mon, 28 Nov 2005 01:35:08 GMT

Guys,
Thanks for the response.

I manage to boot the new server (ML370 G4) with little effort.

here's how:
1. I run back to my mkCDrec cd and boot it to get sh prompt.
2. then I mount the linux partition on the new server and chroot into it.
3. there i recompile my kernel using the same configuration on my previous machine (ML370 G3), including the initrd & System-map.
4. edit the grub.conf, unmount the FS, then boot.

That's it.

Thanks,
EF

Re: Linux Bare Metal Restore to different type server

Emir Faisal — Mon, 28 Nov 2005 01:49:24 GMT

...
my last post lead me to one question:
why should I re-compile my kernel (with the same configuration file), to make my linux bootable ?

Thanks,
EF

Re: Linux Bare Metal Restore to different type server

Gratien D'haese_2 — Mon, 28 Nov 2005 03:38:18 GMT

The difference between G3 and G4 machine is most probably a raid controller which is different.
You should carefully compare the lsmod output of the G3 and G4 system and add the G4 modules not listed in the output of the G3 machine into the Config.sh file of Mkcdrec.
The variables INITRD_MODULES and MODULES. Rebuild mkcdrec on G3. When you boot on the G4 system the modules will get loaded and you can clone happily.
Gratien

Re: Linux Bare Metal Restore to different type server

Emir Faisal — Wed, 30 Nov 2005 05:58:31 GMT

Gratien,
I think the most obvious module is the difference between aic7xxx and mptscsih.
But, I find it difficult to edit value of INITRD_MODULES and MODULES of the Config.sh for the following module list properly:

loaded modules on G4:
vfat
fat [vfat]
nls_iso8859-1
nfs
loop
cpqci
ide-cd
cdrom [ide-cd]
soundcore
nfsd
lockd [nfs nfsd]
sunrpc [nfs nfsd lockd]
pcmcia_core
autofs
bcm5700
usb-uhci
usbcore [usb-uhci]
ext3
jbd [ext3]
cciss
sd_mod
scsi_mod [cciss sd_mod]

loaded modules on G3:
nfs
lockd [nfs]
sunrpc [nfs lockd]
soundcore
nls_iso8859-1
nls_cp437
msdos
fat [msdos]
loop
parport_pc
lp
parport [parport_pc lp]
ide-cd
cdrom [ide-cd]
sg
pcmcia_core
autofs (unused)
bcm5700
st
usb-ohci
usbcore [usb-ohci]
ext3
jbd [ext3]
aic7xxx
cciss
sd_mod
scsi_mod [sg st aic7xxx cciss sd_mod]

Please help,
EF

Re: Linux Bare Metal Restore to different type server

Steven E. Protter — Wed, 30 Nov 2005 08:27:35 GMT

Shalom again Emir,

When you re-compile the kernel, you replace a kernel that is not consistent with the hardware its been moved to with one that is.

Thats why you may need to recompile.

Pondering your other question.

SEP