FreeBSD 6 and MySQL with DBs on a NAS

[Francisco Reyes]

freebsd-stable-archive at cloud9.net writes:

> I wasn't able to find anyone seeing a similar problem as what I describe.
> I'm using FreeBSD 6.1, MySQL 5.0.21 built from ports and a NetApp share 
> provided over NFS.

Recently we have been having problems with Mysql in 6.X (1 machine 6.0 
stable and another 6.1 Stable). In our case it seems the Mysql (4.X from 
ports) was either causing or contributing to the machine crashing.

> Has anyone else ever seen the issue as described in the e-mail below?

I also saw another thread describing Mysql problems in 6.X.. that is what 
made me check in our system if the crashes were related to mysql.
One machine crashed 4 times in 5 days. So far since removing mysql it has 
been ok.. but it has only been 2 days since we removed mysql from the 
machine.

> I currently have MySQL 5.0.22 built from ports on a FreeBSD 6.1 machine
> with the DB data residing on a NetApp share connected via NFS.


Isn't this a bad idea to  begin with?
Using an NFS mount to do database work.

Also NFS in 6.X... specially the client seems to have issues.
I am even considering to move my 6.X machines that are NFS clients back to 
5.5 if I can't find a fix.

In particular if a server dies, the client in 6.X freezes the machine if you 
try to connect to the path that was mounted on the NFS server. Soft mount 
did not help.

> strange thing happens often after a few hours or a couple of days, some
> tables that are very active start to crash for no apparent reason
> as far as I can tell.

I could be wrong, but I think doing a database over NFS is likely not a good 
idea from a performance and stability standpoint. Specially a heavily used 
database.

> Upon moving the DB data to a local drive, the system operates flawlessly
> and has done so for many weeks, but I really need to keep these data on
> the networked share.

Why do you need it in the networked share?
 
> The problem didn't happen when I was using FreeBSD 4.11, it only started
> after upgrading to FreeBSD 6.0 or 6.1.

As I wrote above.. I have very little (approaching none) faith in the NFS 
client in 6.X

Where I work we are even tying to see if we can get a hold of one of the NFS 
developers in FreeBSD and even pay to have this issue looked at.. So far I 
wrote to two of them, but have not heard back from them. I believe I have 2 
more names to try, beyond that I am not sure we can remain with 6.X on the 
nfs clients.

I have yet to try automaunt to see if that would help, but in general even 
when the server is up I kind of wonder if the client is stable.

> A poster on a MySQL mailing list suggested perhaps it could be a file
> locking issue at the OS level and so I post my inquiry here.

That is one of the reasons I am suggesting against using a NFS share to do 
DB work.