Configuring boot partition with LVM (fwd)
As of AIX 4.3.3, you can't boot off of a striped logical volume, although you can have your boot partition mirrored on multiple physical volumes. All of the physical volumes with a copy of the boot lv must be in the boot list. Thats new as of AIX 4.2.0, although you need a couple APARs to have it work right at that version.
I can't remember exactly how they explained it, but IBM has a good reason for not allowing mirrored dump devices. I think the idea is that in order to catch the system dumping in the LVM code itself, you have to write the dump without the aid of the LVM. I think the way that works is that it precomputes a list of offset:extent lists for the device when it is brought online. If anyone really wants to know what goes on behind the scenes let me know -- I've got a couple colleagues that do AIX kernel development at IBM. You are allowed to have a secondary dump device but that only gets used if writing to the first device fails.
Christopher
From: Jens-Uwe Mager <[email protected]>
Quoted 4 lines
At least the IBM people with the AIX LVM are able to make that work. The only thing that they were not able for a long time is to make system dumps work in such a configuration. But I believe that even that works under AIX 4.3.x now.
As of AIX 4.3.3 you can dump to a mirrored device, you can also now stripe and mirror with 4.3.3, a major improvement for production systems.
Quoted 24 lines · Christopher Shaulis
As of AIX 4.3.3, you can't boot off of a striped logical volume, although you can have your boot partition mirrored on multiple physical volumes. All of the physical volumes with a copy of the boot lv must be in the boot list. Thats new as of AIX 4.2.0, although you need a couple APARs to have it work right at that version.
I can't remember exactly how they explained it, but IBM has a good reason for not allowing mirrored dump devices. I think the idea is that in order to catch the system dumping in the LVM code itself, you have to write the dump without the aid of the LVM. I think the way that works is that it precomputes a list of offset:extent lists for the device when it is brought online. If anyone really wants to know what goes on behind the scenes let me know -- I've got a couple colleagues that do AIX kernel development at IBM. You are allowed to have a secondary dump device but that only gets used if writing to the first device fails.
Christopher
From: Jens-Uwe Mager <[email protected]>
Quoted 4 lines
At least the IBM people with the AIX LVM are able to make that work. The only thing that they were not able for a long time is to make system dumps work in such a configuration. But I believe that even that works under AIX 4.3.x now.
Signature · 1 line
Chaos, panic, & disorder - my work here is done.