Alternate boot from same root disk?

[jmb]

I think the answer to this is NO, but I wanted to verify.

Solaris allows you to carve up the root disk (singular) into both the regular filesystems, and also an "alternate boot environment". This is related to their slices, which are not very flexible otherwise. This allows booting from two separate filesystems off of the same hard disk.

This is totally separate from (but does not exclude) any mirroring to a different hard disk.

Can we do this on any HP-UX systems?

[Sundar_7]

I dont believe it is possible.

Infact I am curious about such a possiblity with HP-UX (like you can have a "secondary" /stand which you can boot off).

My understanding is that, the secondary loader (HPUX) considers the first filesystem after the BDRA as the boot filesystem and loads the vmunix file from there.

I believe this is the very reason why /stand should be a HFS filesystem ( secondary loader can only understand HFS filesystem before booting )

[Steven E. Protter · Accepted solution]

HP-UX with LVM does not allow a disk to be in two volume groups. To carve it up and have two boot images, I believe you'd need the disk to be in two different volume groups which can not be done.

I know of know partitioning scheme that would let you get around that.

The path and alternate path are paths to a physical disk. You can also boot of compatible fiber channel based disk arrays, or even an Ignite server through the built in LAN card.

Based on a few years of working with HP-UX I'd pretty much verify your conclusiion at least as far as LVM goes.

SEP

[Salvador González]

In fact, there is support for multiple boot partitions of a disk in the HP-UX Integrity family (Itanium processors).

You can define multiple partitions which can start HP-UX, Linux or Windows 2003, with the "idisk" command. You could also define several HP-UX partitions, and select which one to boot from at the EFI prompt.

[Kent Ostby]

jmb --

You can't have multiple volume groups on a root disk in HP-UX.

HP-UX instead uses the idea of a "recovery shell" available on the install media to give you this type of flexibility.

Also, LVM or VXVM maintanence mode allow you to boot up with a minimal amount of data needed in critical situations.

Best regards,

Kent M. Ostby