system cloning by using mirrored disk

[Torsten Feistel]

Has anyone ever tried to clone a system just by
using mirrored disks. The idea behind this was, that we
have one application running on a L-class server and intend to have exactly the same configuration on a second server, simply inserting the mirrored disks.
Does that work ?

[Paula J Frazer-Campbell]

Hi

This can be "iffy" as all config files, paths and enviroment for the application will have to match.

Safer to install the application and then copy in the data files.

HTH

Paula

[Vincenzo Restuccia]

Yes,mirror your file system after lvreduce -m 0 and insert this disk in the second server.

[Shahul]

Hi

Yaa...If U have same (exactly) hardware configuration , then it will work. Incase if it is not, U will have to resinstall. Because this cloning is not suggested.

Best of luck

Shahul

[Thierry Poels_1]

hi,
I'm not going to say that it's impossible but I wouldn't recommend this option.
I think Ignite/UX is the most preferred way to clone servers (can be downloaded here).
regards,
Thierry.

[Carsten Krege]

This is not a supported way and not recommended. There are some tricky things (e.g. if the hardware setup is different, eg lvmtab wouldn't match) and you have to do a lot of manual changes.

I also recommend against using "lvreduce -m 0". It is even harder to get a system running (changes of the device files, the fstab, order of lvreduce important etc.) that is cloned in this way.

Much easier (and supported) is to use make_recovery(1m) of the Ignite/UX software. This clones your system in a consistent way.

Carsten

[Torsten Feistel]

Thanks for the replies. We will probably choose
make_recovery,seems to be more reliable.

[Magdi KAMAL]

Hi,

I don't think so and you will have a planty of problem inserting mirrored disk into another server, problems for new server are :

1. Hostname
2. IP address
3. Subnet mask
4. Default gateway
5. Mac Address
6. Any external FTP
7. NFS hanging

....


I would prefer :
1. make_recovery command to build a bootable tape from the source server.
2. insert it into the second server and boot.
3. Interrupt the boot processin the ISL level.
4. execute SEA command to look for all known hardware paths.
5. type BOOT P5 ( P5 stand for the tape path for example ).
6. follow instructions to give new hostname, IP address, subnet mask and so on .

Hope this could helps.

Magdi

[Thierry Poels_1]

hmmmm, cloning a server with Ignite/UX or by moving mirror disks to the other server will *BOTH* result in a server with duplicate
1. Hostname
2. IP address
3. Subnet mask
....
That's the idea of cloning ;) These settings must indeed be changed if the server is on the same network.
regards,
Thierry.

[Magdi KAMAL]

Hi Thierry,

I described in my response that, the process of restauting from Ignite-Tape will be interrupted to give other values of network and hostname to prevent against values ambiguity. Cloning servers means for me " To have an identical volume group 00 ( vg00 ) but with different network and hostname values. This is a must ".

I used it and it works really fine.

Bye

Magdi