SUMMARY: NFS problem after upgrading to Solaris 2.4

From: Gunnar Orvarsson (
Date: Tue Apr 04 1995 - 05:19:41 CDT

Dear Sun Managers,

I only got one reply to my query regarding problems with NFS and
Solaris 2.4. The answer was from Casper Dik <>.

In the meantime I've noticed that the Solaris 2.4 kernel patch is
up to version -23 (I was at version -13).

I still haven't had a chance to try it out, so I don't know whether
it makes any difference at all.

Anyway, here's my original question including Casper's comments:

>I've come across a problem with NFS after upgrading a few workstation
>from Solaris 2.3 to Solaris 2.4.

I'm not aware that Solaris 2.3 did the right thing here.

>The problem happens if the Solaris 2.4 machine fills up the NFS mounted file
>system. Then the server almost hangs and displays endless "file system full"
>messages on the screen and the client seems to go on and on writing as it
>seems to be misinformed of the total space left:

The problem is that in SunOS 4.1.x, clients would have at most
64K of outstanding writes. Such would easily all fail.
In Solaris 2.x a client have as much as several MBs of outstanding
writes to a full filesystem.

Plus that the Solaris 2.x NFS code is broken in that it will continue
to retransmit the non-acked arts of the file, instead of dropping everything
written past the logical EOF on the server or perhaps everything written
to that file (it may be sparse). This doesn't happen and has an
severe negative impact on performance.

Similar things happen with quotas.

>[hafmus:mplx] % df -k .
>Filesystem kbytes used avail capacity Mounted on
>hafro:/home/hafro3 222990 200705 4294967282 100% /nfs/hafro/home/hafro3

This data is not used by the client to determine that it can continue to
send data.

>This NEVER happened when the same machines were running Solaris 2.3, so the
>problem may be 2.4 related.

It could be. Perhaps some changes in 2.4 made the problem
much worse. We seem to be having the same problems with disk

Best regards,

Gunnar Orvarsson                                 Internet:
Hafrannsoknastofnunin/Fiskistofa                 Telephone:   +354 5697909
(Marine Research Inst./Directorate of Fisheries) Fax:         +354 5697991
Ingolfsstraeti 1, Reykjavik, Iceland             Home phone:  +354 5813253

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