NFS write corruption on 8.0-RELEASE

[John Baldwin]

On Wednesday 10 February 2010 12:43:38 pm Dmitry Marakasov wrote:
> Hi!
> 
> I think I've reported that before, the I thought it's been fixed,
> however I still get data corruptions when writing on NFS volumes.
> Now I wonder - is nobody really using NFS, or do I have that much
> of uncommon setup, or this is some kind of local problem?
> 
> Client: 8.0-RELEASE i386
> Server: 8.0-RELEASE amd64
> 
> mount options:
> nfs rw,nosuid,noexec,nfsv3,intr,soft,tcp,bg,nolockd
> 
> Server has ZFS, but the same thing happens when sharing UFS placed on
> md(4).
> 
> I've prepared a special 1GB file to determine the details of corruption:
> it's filled with 32-bit numbers each equal to it's own offset in the
> file. That is, like that:
> 
> 00000000  00 00 00 00 04 00 00 00  08 00 00 00 0c 00 00 00  |................|
> 00000010  10 00 00 00 14 00 00 00  18 00 00 00 1c 00 00 00  |................|
> 00000020  20 00 00 00 24 00 00 00  28 00 00 00 2c 00 00 00  | ...$...(...,...|
> 00000030  30 00 00 00 34 00 00 00  38 00 00 00 3c 00 00 00  |0...4...8...<...|
> 
> I've copied that file over NFS from client to server around 50
> times, and got 3 corruptions on 8th, 28th and 36th copies.
> 
> Case1: single currupted block 3779CF88-3779FFFF (12408 bytes).
> Data in block is shifted 68 bytes up, loosing first 68 bytes are
> filling last 68 bytes with garbage. Interestingly, among that garbage
> is my hostname.

Is it the hostname of the server or the client?

> Case2: single currupted block 2615CFA0-2615FFFF (12384 bytes).
> Data is shifted by 44 bytes in the same way.
> 
> Case3: single currepted block 3AA947A8-3AA97FFF (14424 bytes).
> Data is shifted by 36 bytes in the same way.
> 
> Any ideas?
> 
> PS. Diffs of corrupted blocks in a text format are here:
> http://people.freebsd.org/~amdmi3/diff.1.txt
> http://people.freebsd.org/~amdmi3/diff.2.txt
> http://people.freebsd.org/~amdmi3/diff.3.txt

Can you reproduce this using a non-FreeBSD server with a FreeBSD client or a
non-FreeBSD client with a FreeBSD server?  That would narrow down the breakage
to either the client or the server.

-- 
John Baldwin