Swap info

[Filosofo]

Hi,
somebody can tell me something about the different between primary and secondary swaparea; and I can configure?

Thanks

Filo

[Stefan Farrelly]

take a look at;

man 1m swapon

This gives really good detail on swap.

Primary swap is the first/initial swap area created when the operating system is installed. It is mandatory.

Later, you can add secondary swap - which doesnt have to reside on the boot or system disk, it can be anywhere. Generally as you add more memory to a server you add in more secondary swap. Primary swap is left at the size is was set to when the os was installed.

You can configure secondary swap easily, add new ones, remove some, re-priorotise using swapon or editing /etc/fstab.

[Michael Steele_2]

Gee...???, I was going to reply but I don't think there's any room left. :-(

[Pete Randall]

Yeah - something about guys named Steel, I guess. They're a long winded bunch.

;^)

Pete

[Michael Steele_2]

Word of advice, mirror your swap when the time comes.

Not mirroring swap is some kind of urban myth that has permeated the HP-UX community and should be expunged. Why? Look around and see if you can find a swapoff command. No? That's because there isn't one. Secondary swap is removed by commenting out its entry in /etc/fstab and REBOOT'ing the server. Emphasis on REBOOT'ing the servers.

So let???s say you loose the disk that your 2ndary swap resides upon. What happens? Reboot, I mean, PANIC. This is the only way the server can deal with the loss of swap.

Now let???s say you mirror your 2ndary swap. Loose a mirror. No problem.

[Michael Steele_2]

Dear Pete:

Well, when you're out of contract and looking for another in CENTRAL NJ, USA you write elaborate yet concise replies to questions in the itrc forums because, well, you got to have someone to talk to and the wife doesn't listen.

[Pete Randall]

Frederick,

I sympathize, both about the job prospects and about the wife issues. Isn't it amazing how they can ignore you for months on end, yet quote you exactly when they need to chew you out about something you said last year?

Pete

[Michael Steele_2]

HAHAHAHAHAHA....

That is sooooo true.

They also remember every gift and present from every relative ever given for years upon years and hold all accountable at Xmas and B-Days. Its one of many phenomena???s that totally amazes me about motherhood.

[Rita C Workman]

Hmmmm....men

....enough said.


TeeHee,
Rita