Timo Sirainen wrote:
http://dovecot.org/tools/nfstest.c
I wrote a test utility that tests different ways to flush NFS attribute
cache and data cache. Please test in your NFS setup and show me the
results, so I can make Dovecot v1.1 works well with NFS.
Run the test several times (3 should be enough) to make sure the output
stays the same, because the attribute cache flushes might incorrectly
say "OK". And of course attribute cache must not be disabled for this
test to work.
If you have other ideas how to flush either cache please tell me and
I'll update the test utility. I'd like to have a way to flush the cache
without having the NFS client send anything to server. Unfortunately all
of the below ways do that.
Results for Linux v2.6.15 and v2.6.18:
** Test 1
Machine 1: Fedora Core 6, Linux 2.6.20-1.2952.fc6 #1 SMP Wed May 16
17:59:13 EDT 2007 i686 athlon i386 GNU/Linux
Machine 2: Fedora Core 7, Linux 2.6.21-1.3228.fc7 #1 SMP Tue Jun 12
15:37:31 EDT 2007 i686 i686 i386 GNU/Linux
NFS Server: Trustix Secure Linux 2.2, Linux 2.4.34-1tr #1 Thu Jan 4
11:36:05 GMT 2007 i686 i686 i386 GNU/Linux
Because the server is Linux 2.4, that implies the protocol is NFS
version 3.
Info: Connected: client
Info: O_EXCL works
Info: Testing attribute cache..
Info: Attr cache flush fchown(-1, -1): failed
Info: Attr cache flush fchown(uid, -1): OK
Info: Attr cache flush fchmod(mode): OK
Info: Attr cache flush chown(-1, -1): failed
Info: Attr cache flush chown(uid, -1): OK
Info: Attr cache flush chmod(mode): OK
Info: Testing write flushing..
Info: Write flush no caching: failed
Info: Write flush fcntl(shared): OK
Info: Write flush fcntl(exclusive): OK
Info: Write flush flock(shared): OK
Info: Write flush flock(exclusive): OK
Info: Write flush reopen: OK
Info: Testing data cache..
Info: data cache: Reading EOF requires attribute cache flush
Info: Data cache flush no caching: failed
Info: Data cache flush attr cache: failed
Info: Data cache flush fcntl(shared): OK
Info: Data cache flush fcntl(exclusive): OK
Info: Data cache flush flock(shared): OK
Info: Data cache flush flock(exclusive): OK
Info: Data cache flush dotlock: failed
Info: Data cache flush O_DIRECT: OK
** Test 2
Machines 1 and 2 switched roles.
Info: Connected: client
Info: O_EXCL works
Info: Testing attribute cache..
Info: Attr cache flush fchown(-1, -1): failed
Info: Attr cache flush fchown(uid, -1): OK
Info: Attr cache flush fchmod(mode): OK
Info: Attr cache flush chown(-1, -1): failed
Info: Attr cache flush chown(uid, -1): OK
Info: Attr cache flush chmod(mode): OK
Info: Testing write flushing..
Info: Write flush no caching: failed
Info: Write flush fcntl(shared): OK
Info: Write flush fcntl(exclusive): OK
Info: Write flush flock(shared): OK
Info: Write flush flock(exclusive): OK
Info: Write flush reopen: OK
Info: Testing data cache..
Info: data cache: Reading EOF requires attribute cache flush
Info: Data cache flush no caching: failed
Info: Data cache flush attr cache: failed
Info: Data cache flush fcntl(shared): OK
Info: Data cache flush fcntl(exclusive): OK
Info: Data cache flush flock(shared): OK
Info: Data cache flush flock(exclusive): OK
Info: Data cache flush dotlock: failed
Info: Data cache flush O_DIRECT: OK
Andrew
