topic Re: Swap space for 11.31 VM host installs with large amount of ram in Operating System - HP-UX

Swap space for 11.31 vm host installs with large amount of ram.

George_Dodds — Wed, 12 Jun 2013 16:59:02 GMT

Allo, can anyone point me towards latest offical hp docs with recommended swap size for 11.31 vmhosts?

The current install i'm working on is 1x ram

Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 131008 0 131008 0% 0 - 1 /dev/vg00/lvol2
reserve - 1740 -1740
memory 124568 75824 48744 61%

Version B.04.30.00

In the past i've used 2 x ram , which peeps have been saying is outdated for a while now.

But I read in another post

"We found it documented and actually it was true that when you are hosting VMs you will need swap space equal to twice the sizes of the VMs you want active simultaneously"

Just wondering what the official line is these days.

George

Re: Swap space for 11.31 VM host installs with large amount of ram

Dennis Handly — Wed, 12 Jun 2013 16:50:44 GMT

>The current install I'm working on is 1x ram

This already is way too much for 128 GB.

>But I read in another post

What is the URL to that post?

Re: Swap space for 11.31 vm host installs with large amount of ram.

George_Dodds — Wed, 12 Jun 2013 16:44:40 GMT

Allo Dennis

The link to the thread is - swap space size with big memory

Lots of people have a rule of thumb or personal preference on this, but with single blades now having more ram than superdomes i've worked on, i'm wondering what the official line/best practice is now for vmhosts.

Thanks in advance.

Re: Swap space for 11.31 vm host installs with large amount of ram.

Dave Olker — Wed, 12 Jun 2013 16:47:47 GMT

Current recommendations are in the Integrity VM & vPars v6.2 Admin Guide on page 37:

http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c03689515/c03689515.pdf

• Disk space for each guest operating system, including swap space
NOTE: The VSP requires swap space only as recommended by HP-UX 11i v3.
Otherwise, no swap space is required for Integrity VM.

In other words, configure enough swap for the VM Host system itself as you would any other HP-UX server. You do not need to configure swap space on the VM Host for each VM guest that will run on the host, assuming you're running a recent version of Integrity VM.

Dave

Re: Swap space for 11.31 VM host installs with large amount of ram

Dennis Handly — Wed, 12 Jun 2013 17:12:25 GMT

>The link to the thread is ...

Unfortunately Ken never replied where he saw that documented. :-(

And now Dave has refuted it.

>configure enough swap for the VM Host system itself as you would any other HP-UX server.

Where is that "any other" documented?

Re: Swap space for 11.31 VM host installs with large amount of ram

Dave Olker — Wed, 12 Jun 2013 17:05:37 GMT

It's documented exactly where I just posted - v6.2 Admin Guide (I provided the link) page 37:

"The VSP requires swap space only as recommended by HP-UX 11i v3"

The way I read that statement is that the swap requirements of the VSP are just like any other HP-UX 11i v3 server. We no longer require you to configure extra swap space for VM guests on the VSP. That requirement was removed as of Integrity VM v4.1. Looking at the v4.1 Release Notes:

3.2.8 No Swap Space Required for Guest Allocation
The Integrity VM Version 4.1 VM Host requires swap space only as recommended by HP-UX 11i v3. Otherwise, no swap space is required for Integrity VM V4.1.

Re: Swap space for 11.31 VM host installs with large amount of ram

Dennis Handly — Wed, 12 Jun 2013 17:14:18 GMT

>just like any other HP-UX 11i v3 server.

What I was asking where is the "any other" documented/recommended?

I.e. George's next question. :-)

Re: Swap space for 11.31 VM host installs with large amount of ram

George_Dodds — Wed, 12 Jun 2013 17:23:55 GMT

>What I was asking where is the "any other" documented/recommended?

I.e. George's next question. :-)

Yep that would be it :-)

This is not my build, i'll just be the monkey supporting it once it's live, so this is more out of curiosity to see how the recommended settings have changed and a chance to update my docs.

Last time I came out of my cave I found out the world wasn't flat! :-)

Re: Swap space for 11.31 VM host installs with large amount of ram

Dave Olker — Wed, 12 Jun 2013 17:26:02 GMT

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c03684531/c03684531.pdf

HP-UX 11i v3 Installation and Update Guide
HP Integrity Server Blades, HP Integrity Servers, and
HP 9000 Servers

March 2013

Page 11 - Disk space requirements for a cold install

Table 3 on page 12 lists minimum disk space recommendations, including swap space

Re: Swap space for 11.31 VM host installs with large amount of ram

George_Dodds — Wed, 12 Jun 2013 17:39:19 GMT

Thanks Dave much appreciated and to Dennis who i'm sure has his batphone alert him of any new posts :-)