topic Re: Sizing Root Volume Group in Operating System - HP-UX

Sizing Root Volume Group

Andrew Moody_1 — Tue, 18 Apr 2006 08:06:45 GMT

I'm currently installing my first new server a rp 3440.

It will be my ignite server as well as my SD-UX server and maybe even an LDAP server if I ever figure that out.

My question is, I have the relative luxury of a pair of 70Gb internal drives to create the root vg using Mirrordisk/UX. All other storage will be on a EVA via Fibre cards.

What I want to know is how big to size the various bits of the root vg.
/
/stand
/var
/usr
/tmp
/opt
/home

Is it worth sizing them to use the whole 70 GB if so where to use the space? Or should I just leave xGb unused and not worry about it?

Your thoughts as ever would be appreciated.
Andrew

Re: Sizing Root Volume Group

Pete Randall — Tue, 18 Apr 2006 08:11:51 GMT

Andrew,

You might just as well use up the whole 70GB - you don't want to mix anything else in with your root VG! You can be very generous with /var, /home, /usr, /opt and your swap space and it should make your life easier later on. I would also leave some space unused just in case you need to expand a file system later on.

Pete

Re: Sizing Root Volume Group

Andrew Moody_1 — Tue, 18 Apr 2006 08:17:15 GMT

Cheers Pete, my thoughts too in many ways. I was thinking use 50Gb and maybe keep 20 back in reserve in case I may any huge miscalculations on file system sizes at this stage.

The box has 8Gb of memory so I guess I'll have to make /stand big enough to take a full dump and swap will need to be reasonably large too. Just wondered how you guys with way more experience that I would divvy up the space between the filesystems.

Re: Sizing Root Volume Group

Andrew Moody_1 — Tue, 18 Apr 2006 08:17:29 GMT

Cheers Pete, my thoughts too in many ways. I was thinking use 50Gb and maybe keep 20 back in reserve in case I may any huge miscalculations on file system sizes at this stage.

The box has 8Gb of memory so I guess I'll have to make /stand big enough to take a full dump and swap will need to be reasonably large too. Just wondered how you guys with way more experience than I would divvy up the space between the filesystems.

Re: Sizing Root Volume Group

Pete Randall — Tue, 18 Apr 2006 08:26:29 GMT

It seems a shame to "waste" so much disk space but with the size of the drives nowdays, there's little else you can do. In the past I thought the 36GB drives left a lot of wasted space left over!

Good luck,

Pete

Re: Sizing Root Volume Group

Patrick Wallek — Tue, 18 Apr 2006 08:43:22 GMT

Hi Andrew,

Here is how I have recently set up a pair of rp4440's with 8GB RAM and the 73GB internal disks:

/dev/vg00/lvol3 524288 141912 379432 27% /
/dev/vg00/lvol1 314736 43672 239584 15% /stand
/dev/vg00/lvol8 4194304 1672024 2502632 40% /var
/dev/vg00/lvol7 4194304 1450072 2722856 35% /usr
/dev/vg00/lvol6 2097152 12560 2070280 1% /tmp
/dev/vg00/lvol5 4194304 2563024 1618600 61% /opt
/dev/vg00/lvol4 2097152 144504 1937560 7% /home

I have 2GB of primary swap (/dev/vg00/lvol2) and I have the 'swapmem_on' kernel parameter set to 1.

You don't necessarily need to worry about having a 1:1 ratio of memory to dump space anymore. There is a package available for 11.11 and 11.23 (I think) called compressed dump that can help out in that area.

Info on that is available here:
http://h20293.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=CDUMP11i

Re: Sizing Root Volume Group

James R. Ferguson — Tue, 18 Apr 2006 08:45:48 GMT

Hi Andrew:

My cardinall rule is to constrain vg00 to *only* the logical volumes standardly defined for vg00.

Chapter-2 of the HP-UX 11i v[1-2] Installation and Update Guide offers a size guideline along with the percent utilization expected for installation of each operating environment type. THe sizes are fairly generous and lead to using about 12-17GB *not* including swap space.

Personally, I provide generous space to '/tmp' and '/var/tmp' particularly for the purposes of patch installation (i.e. using 'swcopy' to merge depots to minimize reboots, etc).

I setup an appropriate primary device swap space and then don't worry about how much un-utilized vg00 space I have. I'd rather grow a filesystem (e.g. /opt) later if I need to do so than to have nothing in reserve or have to shrink something.

Regards!

...JRF...

Re: Sizing Root Volume Group

MarkSyder — Tue, 18 Apr 2006 08:48:27 GMT

I agree with Pete and would add only the suggestion that you give directories such as /var/adm/sw and /var/adm/crash their own filesystems.

If the system needs to write a crash dump to /var/adm/crash, having its own filesystem guarantees there is enough space for the dump even if /var has filled.

Mark Syder (like the drink but spelt different)

Re: Sizing Root Volume Group

A. Clay Stephenson — Tue, 18 Apr 2006 08:57:36 GMT

In your case, I would go ahead and make primary swap 8GB but I would also create a separate dump areas on each of your disks equal to the total of your installed memory.
Although the default is for swap and dump to use the same space, it's dumb. Swap and dump have nothing to do with each other; moreover, swap should always be mirrored and dump should never be. If it is ever actually used, a separate dump space can be a big benefit in getting your machine rebooted because now the image does not have to be compressed and stored with a filesystem before the swapspace might actually be used. About the only concession to these large disks that I would make is expand / to perhaps 400-500MB and /stand to
300MB just to make sure that future upgrades
go well. The other filesystems are so easy to extend that they are not worth worrying about. I see nothing wrong with leaving huge amounts of unused space in vg00 --- just don't be tempted to use vg00 for anything other than the OS.

Re: Sizing Root Volume Group

Bill Hassell — Tue, 18 Apr 2006 18:18:12 GMT

Just a note about /stand...it is not invloved in a crash dump at all. /stand should be about 256 megs and that's it -- almost no growth in /stand. The crash dump(s) go into /var/adm/crash, and for reliability, I'd create a separate lvol about 10-20 Gb just to hold /var/adm/crash. That way, if you forget to cleanup the crash directory, it won't affect /var at all.

Re: Sizing Root Volume Group

Sung Oh — Tue, 18 Apr 2006 20:50:32 GMT

Hi Andrew,

you can consider disk space requirement from HPUX installation guide to decide file partitions.

http://docs.hp.com/en/5990-8144/5990-8144.pdf

look under page 36 for details.

Regards,
Sung

Re: Sizing Root Volume Group

Prashant Zanwar_4 — Tue, 18 Apr 2006 21:45:17 GMT

No option but to install a new disk and ignite that..

Thx
Prashant

Re: Sizing Root Volume Group

Andrew Moody_1 — Tue, 25 Apr 2006 10:36:57 GMT

Thanks for your opinions. In the end I went for the following

root@server:bdf
Filesystem kbytes Mounted on
/dev/vg00/lvol3 524288 /
/dev/vg00/lvol1 505392 /stand
/dev/vg00/lvol8 8388608 /var
/dev/vg00/lvol9 10485760 /var/adm/crash
/dev/vg00/lvol7 4194304 /usr
/dev/vg00/lvol6 4194304 /tmp
/dev/vg00/lvol5 4194304 /opt
/dev/vg00/lvol4 4194304 /home

I'm sure there are better setups and other things to consider, but it's all about learning through experimentation isn't it?

Thanks