sizing / filesystem

[brian_31]

What would be the correct size for / filesystem. I have seen some machines with 5g and some with 150 Meg. Please post pros and cons.

Thanks

Brian

[Pete Randall]

Brian,

I try to keep / generously small and keep everything else out of it. The only things in / should be /dev, /etc, /sbin, /stand, and the mount points for the other file systems. As long as you follow this philosophy, there is no need for more than 150 to 200 MB.


Pete

[Pete Randall]

Sorry, not /stand - make that /usr!


Pete

[Torsten.]

There is not much space needed, but if you have a huge disk (up to 146GB), you can create lvol3 between 200~500MB.
Be aware you cannot increase the size later (only with ignite). So if you have space enough, be generous.

[Bill Hassell]

As mentioned, 200megs is fine. The machines with massively large (5Gb) root filesystems were either created by an admin with a workstation mentality (one giant volume for everything) or by an admin that allowed lousy applications to install in / rather than /opt where they belong. / is basically static -- never grows significantly. That means that the sysadmin(s) research the addition of new files and applications before actually performing the task.

Note also that spelling errors by the root user (ie, tar cvf /dev/rmt/om /var) can cause massively large files (om is not the same as 0m) to be created in /dev which is part of /. And by default, root's home directory is in /, a VERY bad place for any system. It means that the root user always lands in / at every login, making membership in the "rm -r *" club inevitable. Move root's home to either /home/root or to /root to mitigate such damage.

[DCE]

Brian, The / file system *should* only be used by the OS. That being said a size 150 - 200 MB should suffice. However, the adage od " if a user can mess something up, they will" comes to mind. I would recommend a size of 200 - 300 MB based on my experiences of having users say " I didn't know that a full file system would crash the system"

Also, the new root disk are so large today, that you have the luxury of making all of the vg00 lvols larger than the (ridiculously low)default sizes, and still having plenty of space left over.

/ cannot be made larger after the fact (unless you ignite the system), so a little more is not a bad idea.

[A. Clay Stephenson]

Something in the ~200MiB range would be reasonable and would allow room for any future OS upgrades. Bear in mind, that once configured and up and running for a little while, / is all but fixed in size and should not deviate from the equilbrium filesystem usage by more than 2-5% over very long periods of time.

[VK2COT]

Hello,

Various admins have different preferences.

After more than 20 years in Unix,
I like the method that MSDD ESI
World Wide HP-UX Server Build Standards
recommend:

http://ibc-spse.corp.hp.com/CMSG/ux/cmsg-ux.html

For file system sizing:

http://ibc-spse.corp.hp.com/CMSG/ux/Build/filesystem_1111.htm
http://ibc-spse.corp.hp.com/CMSG/ux/Build/filesystem_1123.htm

In Australia, we certaily use them internally
and for our customers. Our Custom Delivery
team tries to follow it as much as
possible...

I also have them as part of my own
Operations Acceptance Testing for HP-UX
servers (see attachment). The Perl script
runs extensive number of tests that saved
me on various projects many times :)
I do update the script in my own time
regularly (because I enjoy it).

Regards,

VK2COT

[David Nixon]

Brian,
On space limited 9GB drives I now use
an 175MB root and this has been OK.
Previously I went down to 128MB but this
proved too much of a squeeze.. For
example running the graphical interface
to VxVM disc admin was enough to fill
root.

DaveN