Booting from previous version of Kernel 11.11 system

[Kenneth Woolard]

Had to boot system using vmunix.prev at the ISL prompt.
Question is does the vmunix.prev replace the current kernel or during the next reboot the system will try and boot from the corrupt kernel ?
If so is it just a matter of going into /stand and rename vmunix to vmunix_corrupt and rename vmunix.prev to vmunix

[Bill Hassell · Accepted solution]

The vmunix files are simple files which will be read into memory at bootup. The default is to always read the /stand/vmunix file so vmunix.prev will only be in memory until the next reboot. Just rename the files while you are running. /stand is usually small so you can remove the vmunix.corrupt file once you have another good kernel file.

[SKR_1]

Boot from previous vmunix and when system comes up then rename this previous vmunix to default vmunix.

Thanks

SKR

[Sandeep_Chaudhary]

does the vmunix.prev replace the current kernel or during the next reboot the system will try and boot from the corrupt kernel ?
ANS: no vmunix.prev doesnt replace current kernel. the default kernel name is decided by AUTO file content.

root>lifcp /dev/dsk/c0t5d0:AUTO -
hpux -lq 52.5.0;0)/stand/vmunix

here the default kernel is "/stand/vmunix" so in this case by default system try to boot from "/stand/vmunix" and not from "vmunix.prev" until and unless u interrupt and mention.


If so is it just a matter of going into /stand and rename vmunix to vmunix_corrupt and rename vmunix.prev to vmunix
ANS: reboot system with "vmunix.prev" and rename ur "vmunix.prev" to "vmunix"