[SOLVED] Configure mysql InnoDB to use data files or log files on NFS volumes??

novice32 · 04-15-2010, 04:05 PM

I was reading http://dev.mysql.com/doc/refman/5.1/...trictions.html which as the following in "Warning":

Warning
It is not a good idea to configure InnoDB to use data files or log files on NFS volumes. Otherwise, the files might be locked by other processes and become unavailable for use by MySQL.

What does that mean, and how can one configure or check to ensure the above is being followed?

rweaver · 04-15-2010, 04:18 PM

You ~really~ don't want your databases sitting on a shared NFS volume... it's a bad idea, NFS can cause a wide variety of locking issues even above and beyond what is listed there. You would be better off setting up replication or something similar if you need multiple hosts accessing the same data.

novice32 · 04-15-2010, 05:58 PM

I guess NFS implies "shared" like a mounted drive accessible to other? If so, I just connected the dots.

chrism01 · 04-15-2010, 07:40 PM

NFS = Network File System
http://en.wikipedia.org/wiki/Network...stem_(protocol)
http://en.wikipedia.org/wiki/Distributed_file_system

paulsm4 · 04-15-2010, 08:15 PM

Hi -

I agree with rweaver. In general, you ~really~ don't want your databases sitting on ANY network shared volume:

Quote:

* Performance:
- Networks are usually orders of magnitude SLOWER than direct hard-disk
- Expensive alternatives (like fibre channel SANs) are an exception ... but you're probably not running fibre channel, are you

?

* Availability
- "locking" is one thing that will reduce availability and reduce performance
- You can easily saturate your LAN if your application is database intensive
- Basic connectivity:
Networks can fail - that's a fact of life.
MySQL (and most contemporary databases) can recover pretty robustly if the physical network layer hiccups during a client/server connection
It's a whole different story, however, if the physical layer hiccups while server is trying to read a database file that happens to be a network share.

If you're going to use a client/server architecture (like MySQL, SQL Server, Oracle, DB2 or Postgres), then your server's database files should be on local disks.

IMHO .. PSM