SUMMARY: unexpected df results

From: Mark G. Thomas (
Date: Tue Nov 24 1998 - 22:25:55 CST


I received a number of helpful responses. Several people suggested that I
must have altered the filesystem minfree space, or pointed out that there
should in fact be minfree space as the latter "df" reports showed.

In this particular case, I was observing different behavior before and
after installing a set of patches, and was wondering which was more correct.

Sean <> and Casper Dik <casper@holland.Sun.COM>
had the answer I was seeking.

As Casper wrote:
> You've just installed [the] ufs patch that fixes the df numbers.
> The new numbers are the correct ones.
> There should be a 10% gap (reserved space) between kbytes and used+avail.
> Casper

I was glad to find out the patches fixed a bug and, and the old df behavior
was incorrect.

I am not positive whether the fix was actually part of the latest
2.6_Recommended.tar.Z, or the mu2 upgrade patch collection, due to
some confusion of mine about which patches I had in fact applied
most recently. According to Sean the bug ID is #4110900.

Here was an excerpt from my original question:

>I just noted that after installing the latest 2.6_Recommended.tar.Z from
>Sunsolve, a lots of "avail" space reported by df has disappeared, and
>the available space is no longer even close to the difference between
>the filesystem size listed and the amount used.
>After installing the patches, but prior to rebooting the system,
>I noted that the difference between the filesystem size, and the
>amount used is not far from the amount listed as available, and the
>percentage capacity seems in line.
>(before reboot)
># df -k
>Filesystem kbytes used avail capacity Mounted on
>/dev/dsk/c0t3d0s0 48023 16269 31706 34% /
>/dev/dsk/c0t3d0s6 480919 386288 94151 81% /usr
>/proc 0 0 0 0% /proc
>fd 0 0 0 0% /dev/fd
>/dev/dsk/c0t3d0s1 240055 24978 214837 11% /var
>/dev/dsk/c0t3d0s5 940478 212797 726114 23% /opt
>After rebooting, and doing nothing else, the machine now reports
>considerably less available, and the numbers don't come nearly as close
>to adding up. For example 46 MB less is listed as available in /usr,
>in spite of negligible change in the kbytes size and used amount listed.


Mark G. Thomas ( --

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