mount point sizes

[Vaish Raj]

Hi,

We are finalizing sizes of vg00 mount points for our new server with O/S 11i Version 1.0.

I believe /(root), /stand, /swap ( primary swap ) need contiguous space and can not be increased in size after creation.

Considering above things in mind, i have few questions :

1) Are there any other mount points which need contiguous space.

2) What are the factors to be considered while deciding the sizes of /(root), /stand mount points and other vg00 mount points

3) What FREE space should be available on these mount points ( in MB ) specially /(root) and /stand for future O/S upgradation

4) We have 4 GB of RAM on server. To start with i want to use less than 4 GB of swap space ( i am not sure of size now ). In case i need extra swap space i will use another disk swap space on another disk.

Any issues with this approach and wants to know what could be lowest swap space for 4 GB Ram.

Thanks

[Patrick Wallek · Accepted solution]

1) No. Nothing other than /, Pri. Swap and /stand need be contiguous.

2) How much other software will you install (both non-HP and HP). How often will you patch? Remember that /var/adm/sw will contain ALL SD information including all backout information if patches need to be uninstalled.

3) Good question. I recently installed an HP-UX 11iv2 (on PA-RISC) system and made my / to be 512MB and /stand to be 300MB. I think that should be enough to hold me for a long time (I hope).

4) Sounds good. I might try a Pri. Swap of 2GB and make sure that the kernel parameter swapmem_on is set to 1.

Your mount point sizes will depend on how much disk space you have. If I have sufficient disk space I generally make /var, /opt and /usr at least 3 GB. /tmp and /home can be whatever is appropriate for your site. I have never done it, but some people also prefer to create a separate mount point for /var/adm/sw since that is generally what takes up the most space in /var.

Good luck.

[Stf]

Hello,

I install a lot of machine by week and the configuration of my fs I use is:

/stand min 100MB
/ min 500MB (normally if you make good choice / should never increase)
swap 2x physical memory / max 2048
/usr min 650MB (depend if you plan to install lots of local applications)
/var min 450MB
/opt min 500MB
/tmp min 100MB

For your case it depends how much applications, softwares and database you want to install...

Stf ;-)

[Sanjay_6]

Hi,

Only root (/), boot (/stand) and swap needs to be contiguous. No other filesystems has to be contiguous.

Since we hardly put anything other than the OS on root, we can live with 256MB of root. Just do a search on the forum and you can get lots of suggestion on the sizing. same with the swap sizing.

Hope this helps.

Regds

[Marvin Strong]

It depends whats the servers function?

Are you pseudo-swap enabled? Or not?
Reguardless I would have a min of 4G of swap. Probably more if you are not using pseudo-swap.

Also if you are going to have a large amount of large vg's(ie lots of disks and lvs) /etc/lvmconf has a habit of taking up alot of space for all the vg*.conf files. If you have alot of big vg's.

[Pete Randall]

1) No, those are the only mount points that need to be contiguous.

2) The main factors are: /stand needs to be big enough to build a new kernel in - 300MB should do; / (root) should be pretty much static with no growth in a properly configured system - 200MB should be good.

3) My / (root) has 36MB free, my /stand has 164 MB free

4) The old days of using twice the RAM size are just no longer valid. You *should* be able to get away with just 4MB, depending on what you intend to run for applications on this server. An Oracle DB server, for example, is probably going to need both more memory and more swap to run well at all.


Pete

[RAC_1]

Yes. /stand, /swap and / has to be contgeous.

1. No other lvols need to be contigeous. But I have seen that few guys keep /tmp contigeous. Don't know why.

2. /, /stand are staic. What it means is their sizes should not change. swap can be very little. (primary swap), yu can add secondar swap (better if you use another disk than the primary swap) For other partitions-it depends. e.g if you are going to install lots of optional products, /opt needs to be large enough. the sizes that I have on my system are as follos.

/dev/vg00/lvol3 147456 54904 91832 37% /
/dev/vg00/lvol1 149424 69016 65464 51% /stand
/dev/vg00/lvol8 262144 86360 174856 33% /var
/dev/vg00/lvol13 262144 13097 233540 5% /var/stm
/dev/vg00/lvol12 524288 62453 433031 13% /var/opt/perf
/dev/vg00/lvol9 524288 12001 480288 2% /var/adm
/dev/vg00/lvol11 1048576 94677 894340 10% /var/adm/sw
/dev/vg00/lvol10 5242880 7202 4913248 0% /var/adm/crash
/dev/vg00/lvol7 1310720 970144 337944 74% /usr
/dev/vg00/lvol6 262144 22504 239640 9% /tmp
/dev/vg00/lvol5 2097152 1998104 99048 95% /opt
/dev/vg00/lvol4 524288 167096 354520 32% /home

3. I keep / and /stand reasonably large. I keep about 300 mb more than what typical sizes are.

3. As explained, primary swap can be very little. You can have large seconday swap (better to keep on different drive than the primary swap). You can start with 1GB primary swap.

Anil

[Vaish Raj]

Sorry for delay in submitting points. Thanks for the info provided.

Can someone clarify this for swap :

Performance wise is it better to have 4 GB of primary swap on vg00 OR create two disk swap of 2 GB each with equal pripority ?

Thanks

[Pete Randall]

For performance purposes, it would be better to split your swap area over two separate disks so that the I/O would be distributed. However, the problem is that, once you start swapping, your performance is going to be so bad that this tiny little improvement will go un-noticed.


Pete

[Patrick Wallek]

Performance wise -- it doesn't really matter.

If you actually get to the point where you are paging out (swapping) to any significant degree, your overall system performance will be so bad that it won't matter.

It's best to over-config on RAM initially so you don't have to worry too much about swap.

[Geoff Wild]

It is best to split your swap - for performance.

However, it is best to have a swap device on vg00 = to ram size as it is used for dump space.

I alos like to create a seperate /var/adm/crash mount point - 512MB larger then ram size.

Rgds...Geoff