Coda File System

Re: Problems with mysql

From: Jan Harkes <>
Date: Fri, 2 Feb 2001 12:14:45 -0500
On Fri, Feb 02, 2001 at 04:00:13PM +0100, Steffen Neumann wrote:
> Hi,
> I have problems with mysql-3.22.32,
> which won't start if it is to store its data 
> to our coda partition. 
> I tried mysql-3.23.32 as well, same problem.

First of all, Coda is not a magic bullet that will suddenly make mysql a
replicated database for you. When multiple mysql daemon on different
clients try to access/update the database you will get nasty conflicts.

> General question: how to debug those problems 
> that might be coda related ?
> >From the strace attached below I see that
> line 23 differs, where it reads back the data 
> sent to ./mysql/bla.frm with pwrite() in line 11, 
> after the lseek(SEEK_END) in line 9.
> Is there documentation what filesystem features 
> or system calls coda does not support ?

Coda should support all basic read/write/mmap related system calls. It
looks like a subtle pagecache problem in the kernel. The data might be
written into the Coda inode page mappings, and read from the underlying
container inode pages. Adding an fsync right before the close might
actually show that the problem disappears.

What kernel version are you using?

Received on 2001-02-02 12:14:50