On Sun, 1 Sep 2002, Harold Gutch wrote:

> > 	Have you tried setting options NFS_BOOT_RWSIZE=1024 in the kernel
> > 	config, and mounting any additional nfs partitions with
> > 	-r=1024,-w=1024 ?
>
>
> Yes, NFS_BOOT_RWSIZE is set to 1024 in my kernel.
>
> This is weird - after adding -r=1024,-w=1024 to the line for my
> root-directory in /etc/fstab, I get the corruption after 4096
> bytes already:
>
>   $ cp /netbsd /tmp/netbsd
>   $ dd if=/netbsd bs=4096 count=1 | md5
>   1+0 records in
>   1+0 records out
>   4096 bytes transferred in 0.001 secs (4096000 bytes/sec)
>   fcbd92b184bebf1e7c7a2220d362aba1
>   $ dd if=/tmp/netbsd bs=4096 count=1 | md5
>   1+0 records in
>   1+0 records out
>   4096 bytes transferred in 0.001 secs (4096000 bytes/sec)
>   fcbd92b184bebf1e7c7a2220d362aba1
>
> but:
>
>   $ dd if=/netbsd bs=4097 count=1 | md5
>   1+0 records in
>   1+0 records out
>   4097 bytes transferred in 0.010 secs (409700 bytes/sec)
>   63f023be8e2f8a3c212484f4d8ff8104
>   $ dd if=/tmp/netbsd bs=4097 count=1 | md5
>   1+0 records in
>   1+0 records out
>   4097 bytes transferred in 0.029 secs (141275 bytes/sec)
>   70634370db332a87292bd40f8ef7334e
>
> I now also compared around byte 4096 in /netbsd and /tmp/netbsd
> with hexdump:
>
> /netbsd:
> 0001000 51d2 1a1c 6fe3 4f26 6ef6 6df6 6cf6 6bf6
> 0001010 6af6 69f6 000b 68f6 0400 4000 1000 0200
> 0001020 0100 0080 0000 0800 0006 0010 0003 0010
> 0001030 2fe6 6ef3 e001 6fe3 000b 6ef6 2f86 2f96
> 0001040 2fa6 2fb6 2fc6 2fd6 2fe6 4f22 7ffc 6ef3
>
>
> /tmp/netbsd:
> 0001000 0000 0000 0000 0000 0000 0000 0000 0000
> *
> 0001020 0100 0080 0000 0800 0006 0010 0003 0010
> 0001030 2fe6 6ef3 e001 6fe3 000b 6ef6 2f86 2f96
> 0001040 2fa6 2fb6 2fc6 2fd6 2fe6 4f22 7ffc 6ef3
>
>
> The first 32 bytes of every 4096 byte block (except for the first
> one) seem to be corrupted.

	Very odd. Is 'sysctl hw.pagesize' 096 on the dreamcast?
	I'd be inclined to play with any of the available mount
	options (v2/v3 tcp/udp) to see if they affect matters.

	What OS is your NFS server running (I don't think that
	would be relevant, but it might be worth testing another).

	You could always nfs export a small mfs from the dreamcast to
	itself and test on that...

-- 
		David/absolute          -- www.netbsd.org: No hype required --