Where can I find valid dump areas

[Wim Rombauts]

I am about to double the amount of memory in my machine.
This is no problem for swap, since I can add additional swap on other volume groups in the system. But what about dump area's ?
Do they have to be on the root VG, or can I use any swap area as dump area ?
Is there a way to use the second side of a mirrored swap device on the root VG (I now only use one side of the swap device as dump area). lvlnboot -d only seems to take LV's as target and that doesn't give me the possibility to specify what side of the mirror to use. lvlnboot -v shows me I am using the swap device, but only one physical device of the mirror. (The swap device itself is mirrored).
The problem is that I have rather small root disks (2GB) and there is not realy enough room to fit a 1.25GB dump area on it.

[harry d brown jr]

Which OS revision (10.20, 11.00, or 11i) do you have?

live free or die
harry

[Jeff Machols]

The dump device can be non rootvg, the only catch is the LV must be contigous.

[Jeff Machols]

Also, bad block allocation must be off. If you run a crashconf -v, it will show the output of your current set up including which device is used. Do an lvdisplay on that and create a new LV with the same config. Then run crashconf /dev/vgXX/newdevice to change the dump device

[Wim Rombauts]

I am using HP-UX 11.0.

I have a non-contiguous swapspace, created with the distributed mirroring option, but it is created in one lvextend operation. If you are right, Jeff, I cannot use this swapspace for dump.

[A. Clay Stephenson]

Hi:

Don't overlook the fact that dump does not have to also be swap. This is not as nutty as it sounds. One method is to have a very small primary swap (256-512MB - should be mirrored) and the other swap can be anywhere. If you have enough memory so that you never swap, you can even use filesystem swap at low priority or use pseudo-swap. The dump area can then be anywhere and there is no need to mirror it. It also elimates to the 50/50 crapshoot as to where it's actually going that you have found using mirrored swap which is also dump.

Food for thought, Clay

[Sanjay_6 · Accepted solution]

Hi Wim,

Here is a link from hp docs site on managing dump,

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90742/B2355-90742_top.html&con=/hpux/onlinedocs/B2355-90742/00/00/50-con.html&toc=/hpux/onlinedocs/B2355-90742/00/00/50-toc.html&searchterms=dump&queryid=20020114-081502

hope this helps.

Regds

[Wim Rombauts]

Hello Clay,
I thought I read somewhere that the dump area should be in the first 2GB of a physical disk.

I have an unused 2GB area available, but it's the last part of a 4GB disk drive. I have allways wanted to use this as dump area, but I thought this was impossible due to the 2GB limit I read somewhere.

[A. Clay Stephenson]

Hi again:

There are a few restrictions depending upon the OS. For example, in 10.20, the dump area has to be in vg00; that doesn't mean it has to be on the boot disk. Also, you can have multiple dump areas. You should put them in the first 2GB area of a disk and in general the dump areas should fit (not merely begin) in the first 2GB. The dump area must be contiguous lvols. In 11.x, the restriction that the dump area must reside in vg00 is removed. In your case, since you indicated a small 2GB boot disk, if you extend vg00 you will only be able to see the first 2GB's of any disk in vg00 anyway.

I really prefer to have separate dump areas because I just can't bring myself to mirror lots of swap for disk that I never use. That's why I bought all that memory in the first place.