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From:SGreen Date:July 6 2005 4:14pm
Subject:Re: Network drive
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Ruben Carvalho <carvalho_ruben@stripped> wrote on 07/06/2005 11:06:10 
AM:

> I think I haven't understood your question. I guess
> that in case of a network failure you can have the
> same behavior as a power shutdown.
> 
> About the networked drives? Anyone?
> 
> 
> --- Martijn Tonies <m.tonies@stripped> wrote:
> 
> > Hi Ruben,
> > 
> > > I would like to make a short, quick and simple
> > > question.
> > >
> > > Is it possible to have the following line:
> > >
> > > innodb_data_home_dir="X:/data/"
> > >
> > > in a my.ini config file?
> > >
> > > I'm using windows XP, mysql 4.1.12, X: is a mapped
> > > network drive to a Linux folder using samba, all
> > the
> > > permissions are set and tested.
> > >
> > > I have seen this posted many times but without
> > many
> > > replies. I want to use a folder in a mapped drive
> > to
> > > save my InnoDB data. Is this possible?
> > 
> > I don't know this particular answer for MySQL, but I
> > do have 1 question:
> > 
> > If the database engine doesn't have control over the
> > files
> > and/or drive, what should it do in the case of a
> > network
> > failure?
> > 
> > Let alone the latency of a networked file...
> > 
> > With regards,
> > 
> > Martijn Tonies
> > Database Workbench - tool for InterBase, Firebird,
> > MySQL, Oracle & MS SQL
> > Server
> > Upscene Productions
> > http://www.upscene.com
> > Database development questions? Check the forum!
> > http://www.databasedevelopmentforum.com
> > 
> > 
> 
> 
> Rúben Carvalho

RDBMS over a network: NOT recommended. Not only can you not enforce 
OS-level locking on your files (maybe you can, I guess it may depend on 
your device and inteface protocols) but the MOST COMMON bottleneck to 
database performance is disk I/O. If you went with networked storage, you 
are not only going to suffer through disk lag (seek time + rotational 
positioning before the operation can start) but you are incurring network 
overhead on top of it IN BOTH DIRECTIONS.

Unless your network device is flash-only (all memory, no disks), you just 
cut your throughput by at least 75%. And even if your device is flash-only 
you will reduce your data throughput by 25-50% (all performance numbers 
are rough estimates pulled out of my a** but based on the number of extra 
network hops necessary to get at and read your files).

I don't care how fast your network is, networked storage can't be as fast 
as local disks. Again, it is highly discouraged to use networked storage 
for anything but the most trivial database uses (small file sizes, low 
traffic, etc). For any application that requires even modest performance, 
spend your money on a fast RAID configuration. You will be much happier in 
the long run.

Shawn Green
Database Administrator
Unimin Corporation - Spruce Pine
Thread
Network driveRuben Carvalho5 Jul
  • Re: Network driveMartijn Tonies5 Jul
    • Re: Network driveRuben Carvalho6 Jul
      • Re: Network driveSGreen6 Jul
        • Re: Network driveRuben Carvalho6 Jul
          • Re: Network driveSGreen6 Jul
            • Re: Network driveRuben Carvalho6 Jul
              • RE: Network driveJ.R. Bullington6 Jul
                • RE: Network driveSGreen6 Jul
            • Re: Network driveRuben Carvalho7 Jul
          • Re: Network driveJamesDR6 Jul