AIX

Hi,

I just want to ask whether anyone has experience on restoring mksysb backup in NIM. We have taken the mksysb backup and the SPOT has been configured on NIM also. I just want to know the checkpoints before doing this. Is there any checkpoints we need to do? Do we need to unmirrorvg? This server is running HACMP. Thanks.

Yes, of course. It is actually hard to avoid when you work with AIX.

I don't know what you mean by "checkpoints". If you have used the NIM methods to create the mksysb you have already established a working communication between the NIM server and the client. If you want to restore the mksysb image to the client create a NIM resource for this client, shutdown the client, start it into the SBB menu, enter the IP address of the NIM server into the appropriate menu screens and off you go. NIM relies on bootp as a protocol, therefore all the routers, switches and whatever network equipment you have between client and server have to pass through bootp.

Further, there is a common problem with exports: NIM will create a (temporary) NFS share (/etc/exports) for the client on the server. If a superdirectory of this share is already exported this may (or may not) confuse NIM. The best way to avoid this is not to export any superdirectory of the place where the NIM resources are located.

If you run a server with HACMP this is indicative of the server being quite critical to some operation. In such a case not having tested backup and restore of the system before commissioning it is somehow careless, isn't it? In this case you should announce some downtime with the users to test the process. It is almost 100% foolproof and rarely fails, but in the remote case of failing you will not have to explain why you're testing on a productive system.

Anyway you don't have to unmirror anything: a mksysb image is basically a "savevg rootvg" and contains not only the data of the rootvg, but also the disk layout, the filesystem layout, etc..

I hope this helps.

bakunin

Hi bakunin,

Thanks for the prompt help. I thought that the server will be rebooted automatically when you do a administration task in NIM? I have found the below link. Can you please verify that the informations and steps provided are correct:

(uN)Tech blogs: AIX 5L NIM mksysb restore

These are newly configured servers (not live yet) but the client need to test backup and restoration from NIM. Do you have any site where explains the step by step procedure? I just want to be safe. Thanks

The description seems to be to the point. In case you are not familiar with the NIM concepts you might want to read this little description.

Btw., just to be sure: you can create an mksysb image into a file on the client machine too - this is NOT a valid NIM resource, even if it is more or less the same. For NIM it is NOT the same. You have to create a mksysb image through NIM means on the server (like it is described in the document you linked) to get a valid NIM resource to boot from.

I hope this helps.

bakunin

Hi Bakunin,

Thanks for the help. I will try this one and let you know. Hope everything goes smooth and if not I hope I can ask again for help. Thanks a lot.

---------- Post updated 04-06-10 at 03:37 AM ---------- Previous update was 04-05-10 at 08:12 PM ----------

Hi Bakunin,

Just an update. I seek IBM engineer advice to make sure everything works fine. He told me to do the following:

1.) unmirrorvg hdisk1
2.) reducevg hdisk1
3.) bosboot -a hdisk1
4.) bootlist -m hdisk0
5.) Create mksysb via NIM
6.) Install in hdisk0

If everything fails, I can still set the boot device to hdisk1. I am going to do it tomorrow. So does it mean that if I trigger the backup in NIM the server will automatically restart and I will need to set the IPL to network?

Thanks and Regards,
Don

This is true in a way: if you break the mirror you have two identical copies of the rootvg and if you destroy one you still have the other. The same principle is used in the alt-disk-install procedure.

I still don't think this is necessary because you said above that the server is not commissioned yet. The worst which could happen is that you will have to set up the server from scratch.

While the IBM engineer is right about this being the most failsafe procedure it also introduces a little uncertainty because you are not testing what you will use in production. I prefer to make my tests always as close to production as possible.

Not at all! If you trigger the backup on the NIM server it will create a NIM resource of type mksysb, nothing more. You will have to allocate this (and a few secondary) resource(s) and generally the follow procedure for installing NIM clients from a server to reinstall your system using this mksysb image. You will also have to manually stop the client and initiate the reinstall in the POST-menu there.

I hope this helps.

bakunin

Hi bakunin,

Thanks for the prompt reply. I just found out that I don't have the fileset
bos.alt_disk_copy.rte which is needed for cloning the disk to hdisk1
and I only have the bos.alt_disk_install.

Though the server is not live yet and the worst thing that could
happen is to reinstall everything, we really cannot afford to
reinstall since most of the vendors are from different parts of
the world who flew in here to do the configuration and installation

There are some application specific configuration in the rootvg
that we could not replicate if any damage is done on the rootvg.

Moreover, I have already have the mksysb and have the SPOT which
is of the same TL level. From the previous document I showed you
I can do the following:

1.) smitty nim_bosinst
2.) choose mksysb
3.) choose the SPOT image

If you are not that busy, can we chat so I can ask some questions?

Thanks and Regards,
Don