Dynamically Updating the Kernel on the Fly?

[Shaun Aldrich_1]

Good morning everyone,

Just wondering if anyone has heard of any thoughts of future releases of HP-UX to contain the ability to update the kernel on the fly? That is, if I am applying patches for example that affect the kernel then I have to reboot the machine. It would be nice if in a future release if the kernel could just be dynamically updated. Just a thought.

S Aldrich

[CHRIS_ANORUO]

I have not heard of it. How would your kernel recognise the new updates to your system?

[Shaun Aldrich_1]

Hi Chris,

I am not sure how the kernel would recognize the changes / updates. I would however consider this to be a break through in UNIX technology as this would require you to reboot your machine even less. As it is in UNIX you already are fortunate to reboot a lot less than in Windows.

S Aldrich

[Patrick Wallek]

I believe that HP is working on a dynamic kernel. There were, I think, supposed to be some DLKMs, Dynamically Loadable Kernel Modules, that shipped with 11i, but I think the release of those got pushed back.

I just briefly searched HPs web site for information, but couldn't find any. You might just browse the HP-UX 11i site and see if you can find anything.

http://unix.hp.com/operating/index.html

[Alan Riggs · Accepted solution]

The hooks for dynamic kernel modules have been in place since 11.00, but HP has yet to "attach" anything to them (AFAIK). Dynamic kernel updates are not unknown in the unix world. AIX has been doing them for years. There are downsides to it too, though. In particular, dynamic updates require a database structure to similar to the aix odm or Windoze registry. This means many of the standard unix methods for handling kernel builds (and perhaps device installation/removal) must be obsoleted or kluged to address the new structure. Nothing is free.

Good points: increased uptime -- ease of scheduling kernel updates, etc.

Bad points: Loss of flat configuration files to control/query kernel structures, possible loss of command line interface to generate new kernel (HP has at least floated the idea that modifications to dynamic structures will have to be done through SAM.)

[Kenneth Platz]

Shaun,

HP-UX 11.0 includes support for Dynamically Loadable Kernel Modules (DLKM's), however AFIAK, these are not seeing much use as of yet.

HP-UX 11i has also introduced support for dynamic kernel tunables, which allows you to reconfigure some of your tunable parameters without a reboot.

Hope this helps.

[Bill McNAMARA_1]

HPUX 11i or 11.11 will do lots of tunables on the fly, either through SAM (preferred) or kmtune.
11i should be available for most of the servers starting support with the Superdome.

11i also supports OLAR, online addition and replacement of IO cards (if your hw supports that)

Moving a step closer to the 5.9s

Later,
Bill

[Bill McNAMARA_1]

Just to add shaun, hpux 11i is available and patches do exist for ignite and support tools right now.
There should be no major headaches upgrading from 11.0 except certain libs/apps may need relinking.

11.21 planned for end of 2002 will be ia64 port of 11i for ia64 ready hardware superdome and the Ls for example.. PARISC development will still exist up to the lets assume 2GHz processor range. Currently at around 600GHz
mark.

Later,
Bill

[Bill McNAMARA_1]

Just to add shaun, hpux 11i is available and patches do exist for ignite and support tools right now.
There should be no major headaches upgrading from 11.0 except certain libs/apps may need relinking.

11.21 planned for end of 2002 will be ia64 port of 11i for ia64 ready hardware superdome and the Ls for example.. PARISC development will still exist up to the lets assume 2GHz processor range. Currently at around 600GHz
mark.

Later,
Bill

[Edward Sedgemore]

weve been using dynamically loadable kernel modules (drivers) for over a year now on HP-UX 11, particularly for Ethershare (for Mac/TCP connectivity). Install the software, load the driver into the kernel on the fly, and off you go. Works a treat. Roll on dynamically adjustable kernel tables!