How do I clone a server via mirroring?

[Kerry Swemmer]

Hi All,

We have two identical HP9000 rp3410 servers running HP_UX 11.23, one being a cold standby of the other. Eventually they will be alternative routes to a database and application on a SAN, but at this point everything is running on the internal disks of primary. Each server has only two internal disks(bay0 and bay2), one being a bootable mirror of the other.

What I would like to do is refresh/clone the standby server from the primary. I am thinking along the lines of:-
1 Shutdown standby and remove bay2
2 Remove bay2 of primary
3 Insert bay2 of standby into bay2 of primary
4 Let the mirroring sync bay0 to bay2 on primary
5 Remove bay2 of standby from bay2 of primary
6 Replace bay2 of primary
7 Resync primary
8 Shutdown primary
9 Replace bay2 of standby
10 Boot up standby off bay2
11 Sync bay2 to bay0 of standby. Standby is now a clone of primary.
12 Disable application on standby.
13 Change hostname and IP of standby back to its own
14 Start up primary

I have made some newbie attempts at this, but ran into problems. Is this sort of approach feasible, or am I way off track? What would the correct way of achieving this be, without Ignite?

[Simon Hargrave]

"What would the correct way of achieving this be, without Ignite?"

That's where your argument breaks down, Ignite is by far the best solution to this! Is there a particular reason you don't want to use it?

[Leif Halvarsson_2]

Hi,
I have tried, cloning servers using HP software mirroring but also I ran into problems.

As mentioned above, use Ignite instead.

[Rajeev Shukla]

As said, i too have tried similar procedure but ran into lots of problems and finially had to consider the Ignite solution. This is where Ignite is very helpfull, mirroring wont solve your purpose.

[Devender Khatana]

Hi,

This process will give a lot of errors saying that the disk does not belongs to this volume group, all those allthough can be overcomed but still this is not the recommended method as this will cause problems even if one of your device is put in a different slot in the standby server. Also can cause network slow down and all as the mac address will not be updated correctly. Therefor ignite seems to be a much better option.

HTH,
Devender

[Kerry Swemmer]

Thanx All,

I don't know Ignite, and as far as I know, I don't have it. Does it cost? Will it ghost the disks completely, i.e. OS plus DB plus App? What other options are there to propagating changes on a primary server to a cold standby, keeping it as identical to the primary as possible?

Cheers.

[Pete Randall]

Kerry,

Ignite is available for free download here:

http://www.docs.hp.com/en/IUX/

It is simple to use, just mount a tape and run
"make_tape_recovery -a /dev/rmt/_mn -I -v -x inc_entire=vg00"

Then mount the tape in your target server and boot off it. You will, because of the -I option in the original command, be put into interactive mode where you can adjust logical volume sizes and change IP addresses or other basic system info. Then it will proceed to build a replica of your original system. Simple!


Pete

[Leif Halvarsson_2]

Ignite is free, you can find more information here:

http://docs.hp.com/en/IUX/

[Devender Khatana]

Hi,

It is available for free as posted above. But more than a cloning software it is a OS backup software. Just in case your primary server fails to boot and you do not have secondry server you can recover the primary server itself without requiring to reconfigure it will all kernel changes, network settings, patches etc.

You can also change file system sizes and other system parameters while recovering a system from an ignite backup.

We normally does a ignite backup of all our production systems every fortnight.
The only thing required after installing ignite Ux is a tape drive and a cartridge and it will dump contents of your OS VG ( vg00) onto this tape.

HTH,
Devender

[Leif Halvarsson_2]

Hi,
What is said above about mirroring and cloning doe's not apply to hardware mirroring (RAID controllers). Cloning can very easy be done if using a RAID-controller( as the controller hides the physical disks from the OS), we regulary use this method on our Windows servers.

Unfourtunatly, internal RAID-controllers is not very common on HP-UX servers.

[Kerry Swemmer]

Pete,

Great reply, thanx. Do I need a local tape drive? Could I use a local CD/DVD drive?

I love this place.

Cheers.
Kerry.

[Devender Khatana]

Hi,

HPUx does not support writing to CD/DVD. You need to have a local tape drive or you can also configure a ignite server. This ignite server when properly configured can backup all other systems over network itself.

HTH,
Devender

[Pete Randall]

Kerry,

The easiest method is to use a local tape drive. If none is available, the "Ignite-UX Administration Guide" guides through the means of using other media in chapter 8:

http://www.docs.hp.com/en/B2355-90875/ch08.html


Pete

[Pete Randall]

Devender,

Maybe you should take a look at Chapter 8, too!!


Pete

[Torsten.]

Hi Kerry,

current ignite version should be able to write even CD/DVD.
More information you will find here:

http://www.docs.hp.com/en/IUX/

HTH

[Devender Khatana]

Thanks for the update Pete, allthough I am not finding some of the commands like cdrecord with latest ignite version installed. Anyway if it is a possible then it is a great news. Is not it ?

But still I think CD/DVD can not beat the reliability and simplicity of a tape cartridge.

Regards,
Devender

[Pete Randall]

Devender,

I agree - you just can't beat a good, old-fashioned tape drive for backup!


Pete

[Kerry Swemmer]

The Ignite-UX Admin Guide Chapter 8 at
http://www.docs.hp.com/en/B2355-90875/ch08s01.html
says horrible things like
"there is no need for an Ignite-UX server during installation. You do need an Ignite-UX server to create the media."
which I understand to mean that unless you use a local tape drive you have to have a Ignite-UX server configured. Once that is done, then you can do some other fancy stuff, like burn to DVD. So, in my case, the DVD would be a little superfluous anyway.

How local does the tape drive need to be? Could I use a share/NFS?

[Borislav Perkov]

Hi,
You can't use share or NFS, because on the tape there is a boot part and after that there are the files fron the volume group vg00 or esential files in you choose option -A in make_tape_recovery command. What is the way of dooing cloning you can find in manual page for make_tape_recovery command.
Regards,
Borislav

[Kerry Swemmer]

Thanx All, for your wonderful replies. I am now convinced that I need to persue the Ignite-UX solution. However, there is still the outstanding point of how to do it without Ignite-UX. Are we saying that without Ignite-UX we cannot clone a server, or is it so complicated that it is not worth considering, or what? What if they start charging for Ignite-UX?

Cheers,
Kerry.