What files kernel files do i backup before changing kernel parameter?

[Chew Sang Poh]

I just want to find out before i change any kernel parameters, what file do i backup in case i need to revert?

[Michael Tully]

The kernel will already have a backup file. That is the existing kernel. Once you have told the system to boot with a new kernel, the old kernel will be renamed to 'vmunix.prev'

I as a matter of practise always create an ignite tape prior to booting off a new kernel or loading patches.

# /opt/ignite/bin/make_tape_recovery -x inc_entire=vg00 -I -v -a /dev/rmt/?mn

To create new kernel (not using SAM. SAM will create a backup kernel as well)

# cd /stand/build
# /usr/lbin/sysadm/system_prep -s system
# vi system (make your changes)
Save the file
# mk_kernel -s system (generates new kernel)
if no errors
# kmupdate (which will return information as to the booting kernel and the backup kernel)

[RAC_1]

/stand/vmunix --> Ker
/stand/system --> Kernel parameters file.
/stand/dlkm --> Dynamically loaded modules.

[Steven E. Protter]

Always a good idea to backup up /stand/vmunix

If you use sam it handles backups for you.

The normal thing to do is cp vmunix to vmunix.prev

vmunix must be on an HFS filesystem to boot off of it, but if you need to keep a few of them handy, you can store them on a vxfs filesystem.

SEP

[RAC_1]

Also prepare ignite recovery tape.

[Chew Sang Poh]

thank you