[RndTbl] Managing/Growing Disk Space under Solaris

John Schulz jschulz at pbl.ca
Mon Apr 29 14:41:24 CDT 2002

I trying to configure some new storage under Solaris (2.6/8) and wonder if
people would have an opinion of which of the following two solutions would be
best.  I don't have any fancy tools available (like Veritas) and am trying to do
this using basic Solaris tools.  I'm adding large disks (181GB mirrored with
hardware RAID) and would rather that the users not see that they have all the
space before I think they need it.  We all know that any free space will always
be filled when you add new disks.

Possible solutions:
1) When you create a filesystem under Solaris you can set a minfree percentage.
 This percentage (10% by default) of diskspace is kept reserved by the O/S to
optimize filesystem usage.  This percentage can be changed on the fly with
"tunefs" and I was thinking I would start at 60% minfree (40% of disk availabe
to user) and increase as necessary.  This tunefs change can be done on alive

2) It is possible to grow (add sectors) a ufs filesystem under Solaris.  When
you create a filesystem with newfs you can tell it to use less than all the
sectors available on the partition you have specified.  You can then grow this
filesystem to the max sector count of the partition you are using.  The
filesystem doesn't need to be unmounted but become read-only during the grow.  I
believe this was added to support Disksuite objects but also works in ordinary

So, has anyone experience with either of these?



    John Schulz, Manager Information Technology       jschulz at pbl.ca
    Pollard Banknote Limited
    1499 Buffalo Place
    Winnipeg, MB, Canada,  R3T 1L7              204 474-2323 ext 256

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