[xcat-user] Question on filesystems for diskless nodes

[Ling Gao]

 I am doplolying a diskless node (SLES 11 on ppc Lunix).  The
rootimg/etc/fstab looks like this:
   proc                                              /proc        proc
   rw 0 0
   sysfs                                           /sys           sysfs
   rw 0 0
   devpts                                       /dev/pts   devpts
   rw,gid=5,mode=620 0 0
   compute-xcattest_ppc64      /                tmpfs      rw 0 1

When the node is booted up, df command show this:
   Filesystem           1K-blocks      Used Available Use% Mounted on
   compute-xcattest_ppc64
                                   3114560   2222656    891904  72% /
   udev                       3114560   2222656    891904  72% /dev

   'free' does show that total mem is 6g and used 2.5g.
    # free
                total       used       free     shared    buffers
   cached,
   Mem:       6229632    2427264    3802368          0          0
   2203904,
   -/+ buffers/cache:     223360    6006272
   Swap:            0          0          0


The problem is that / and /dev each takes identical amount of spaces.  I
had to allocate 6 gig of memory instead of 3 gig.
I tried to put /dev in the fstab like,
    dev              /dev     tmpfs  defaults,noauto 0 0
or
    none            /dev     tmpfs  defaults,size=10m 0 2
 etc,
 but all end up /dev takes away half of the memory allocated for the node.

I'd like to create more nodes with limited memory. So assigning 6gig to a
node which only uses 2.5 is a big waste.  If I assign 4 gig to the node,
the node, thinking it only has 2gig for the / file system, complains about
runing out of disk space during the deployment. Can anyone shed some lights
on how to resolve this issue?

Ling

Ling Gao
Poughkeepsie Unix Development Lab
IBM Systems and Technology Group
Internal: T/L 293-5692
External: linggao at us.ibm.com, 845-433-5692

"I never worry about the future. It comes soon enough." --- Albert Einstein
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.xcat.org/pipermail/xcat-user/attachments/20090501/50138206/attachment.htm