Re: PostgreSQL, NetBSD and NFS
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: "D'Arcy J.M. Cain" <darcy@druid.net>
Cc: Ian Fry <Ian.Fry@sophos.com>, pgsql-hackers@postgresql.org, current-users@netbsd.org
Date: 2003-02-05T20:09:09Z
Lists: pgsql-hackers
"D'Arcy J.M. Cain" <darcy@druid.net> writes: > On Wednesday 05 February 2003 13:04, Ian Fry wrote: >> How about adjusting the read and write-size used by the NetBSD machine? I >> think the default is 32k for both read and write on i386 machines now. >> Perhaps try setting them back to 8k (it's the -r and -w flags to mount_nfs, >> IIRC) > Hey! That did it. Hot diggety! > So, why does this fix it? I think now you file a bug report with the NetBSD kernel folk. My thoughts are running in the direction of a bug having to do with scattering a 32K read into multiple kernel disk-cache buffers or gathering together multiple cache buffer contents to form a 32K write. Unless NetBSD has changed from its heritage, the kernel disk cache buffers are 8K, and so an 8K NFS read or write would never cross a cache buffer boundary. But 32K would. Or it could be a similar bug on the NFS server's side? regards, tom lane