device files

[Pete Devlin]

Guys I can't open the search page at the moment so I have to ask! Sorry! I have a non mirrored root disk flagged by EMS as needing to be replaced - not a problem. I have an ignite tape but I can't remember whether Ignite puts the device files back as they were or whether new (different) ones are created and I'll need to make mapfiles etc.
Cheers

[Stefan Farrelly]

Ignite creates new device files depending on your hardware layout - so as long as your hardware is the same (disks on same channels, same SCSI address) as it was when the ignite backup was made then it will recreate them the same as they are now.

[Carlos Fernandez Riera]

Iginite will clone the system if it is the same system. This is you ionly change the disk, it will recreate and maintain your actual vision of the hardware.

[John Payne_2]

Ignite doesn't even care if it's a different system, as long as your HW setup is the same. For example, I have 1 image for all my A500/rp2470 machines. You don't have to worry about the device files if things 'look' the same as what you made on the tape. The problem comes when you try to use a tape from a different class of machine, etc.

John

[Judy Traynor]

Actually, ignite simply needs to have a knowledge of the hardware to work properly to restore a system. (with the difference of 700/800 class machines) That information come in the ACE bundles. So, If you have the ACE bundle installed from a relatively recent support plus distribution, you should be able to ignite any class of workstation.
If however, you have an image that has only older patch sets, (specifically ACE) you may not have support for your newer hardware.
good luck

[Pete Devlin]

guys sorry for the late reply
I've been using up my precious holiday before the end of the year or I lose it! In the end we got round the problem by going to single user, replacing the disk & restoring.
Thanks again.
Cheers.

[Bill Hassell · Accepted solution]

Just to clarify a bit: Ignite performs a new installation. What this means is that the device files are created in the order they are discovered during the install. Now, if your system has just one tape and one disk I/O channel and one serial card, etc, all will be well.

However, systems will often grow after initial installation and the device files are created using the next 'instance'. So initially, an I/O card at address 52 will have instance 0 while a new I/O card at address 16 will have instance 1. But reinstalling via Ignite will assign addresses in ascending order (the installer knows nothing of the original history of adding I/O cards). Now, address 16 has instance 0 and address 52 has instance 1.

Now this isn't too bad as instance numbers for disks are seldom important as LVM makes all this transparent. However, tape drives will be a problem. The good news is that insf has an option to create device files with a specific instance number (the -I option). Simply delete the device with rmsf (don't use rm), then add it back using -I.

[Jim Butler]

Ignite will handle it all -
The issues with the hardware model differences can be muted by verifying that the machine that provides the image has the latest ACE bundle on it -

insf -e will recreate all device files, but your mirror issue will be resolved by the ignite restore.