Recommended filesystem size

[Henry Nguyen]

Hello all,

Can anyone tell me what is the recommended size for a filesystem in HP-UX 11.0. What is the advantages or disadvantages of a large filesystem vs small filesystem? Any info on this will be appreciated. Thank you all in advance.

Huy

[A. Clay Stephenson · Accepted solution]

The only answer that makes sense is "it depends". The obvious answer is that a 100GB filesystem with only 2MB of data is a waste of space. The other obvious answer is that when a filesystem is full, the applications die. The best answer is 1) for / & /stand (which can't be resized) allocate them at least twice size (maybe 200MB and 140 MB respectively). 2) The others you don't need to worry about if you have OnLineJFS, you can simply grow the LVOL's and filesystems while the system is still up. If you don't have OnlineJFS, get it - no box should be without it. There aren't any real performance issues of large vs. small filesystems. The thing that you want to avoid is many,many files in any one directory.

[James R. Ferguson]

Hi:

If you are looking for guidelines for the standard OS (vg00) filesystem sizes, see the installation guide for the OS version you are installing or to which you are updating:

For 11.11:

http://docs.hp.com/hpux/onlinedocs/5187-1350/5187-1350.html

For 11.0:

http://docs.hp.com/hpux/onlinedocs/5187-1843/5187-1843.html

Insofar as the advantages and disadvantages of large vs. small filesystems, remember that if you are searching a filesystem from it's mountpoint, the smaller the *number* of inodes (files and directories) the faster the search. There are no performance penalties, per se, for a "large" vs. a "small" filesystem.

Regards!

...JRF...

[Michael Steele_2]

This sounds more like a system performance question and for that you're talking I/O which is dependent upon two basic criteria:

Per process I/O transfer, and,

Total or aggregate I/O transfer.

On your file system, do you have a lot of small jobs and processes running? If true then you???re interested in the total aggregate. If not, if you have a dedicated file system consumed by one application, then you're interested in the per process transfer.

For the total aggregate more disks equate to faster transfer, as well as more disk cache. Like on an EMC disk array.

For per process the larger the file system block size the faster.

Block size can be viewed with the:

du -g /filesystem

Oracle has its own recommendations for block size.

Informix bypasses the file system layer entirely and uses raw logical device, specifically for faster I/O.

One final comment, defragmentation. Invest in online JFS and use it.

[Henry Nguyen]

Thank you all for the info, it was very helpful. I'm about to install oracle 9i on one of the systems and needed to know how large to make the filesystem.

[John J Read]

I give my DBA's 4GB for their Oracle software filesytem. /oracle in my environment. ( contains app/product )

Your data filesystems of course depend on your data.

Here's what we do for the DBA who has no idea what to ask for.

vg01 /oracle 4g
vg02 /oradb01 2g
vg02 /oradb02 2g


Make sure to check kernel parameters for Oracle 9i. There are lots of good posts in the forums on that subject.

[Steven E. Protter]

Here is how I do it for servers that will be doing Oracle

/ 1 G Because I use trusted systems, though I usually move it to a mounted fs, I need lots of space between me and disaster.

swap Twice physical memory, in this case 4G lvol2

/usr 2G To handle all that software I like to add in.

/opt 2G To handle all that optional software I want to add in.

/var 6G The Cold OS install recommended it.

/tmp 1G I need 500 Meg Free to do Oracle installs. Yes I can redirect, but I'm lazy.

What you do actually depends on what you are using your system for.

Oracle /oracle1 control files logs 1G
Oracle data /oracle2 data Depends
Oracle archive logs /oracle3 6 G minimum depending on transaction volume.

/backups for cold oracle backups to be compressed. 16 G again, depends on the database size.

The key theme here is "it depends" As A. Clay points out.

The obvious disadvantage of large filesystems is if you don't use them, you've wasted space. There isn't a performance impact except how you lay them out data versus apps, and how you do raid(raid 10 for oracle).

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