How do you arrive at 16 GB memory ?
Regards
Michael
2008/3/26, Ed Wilts <ewilts AT ewilts DOT org>:
> You didn't specify the OS either. You're going to need some serious staging
> units since you have 400MB of theoretical bandwidth in and about twice that
> out to tape. You either have too many tape drives or they're going to be
> underutilized.
>
> No matter what OS, that memory seems awfully tight. I wouldn't touch that
> config with under 16GB of memory. Instead of 8 LTO-3 drives on a single
> master/media server, you should probably split that up into separate master
> and media servers.
>
> Do the I/O calculations very, very carefully. You're probably not going to
> be able to pull that config off with any Windows server I've seen - you'll
> starve those tape drives since you likely won't even have enough HBA
> bandwidth to drive them. You're far better off driving 4 LTO-3 drives at
> full speed than 8 drives at a slow, shoe-shining speed.
>
> What kills most environments is not CPU but I/O. Don't just assume that
> your disk I/O is adequate - we see destaging performance plummet when we
> write to the same disk at the same time.
>
> .../Ed
>
>
> On Wed, Mar 26, 2008 at 11:06 AM, Michael Graff Andersen <mian71 AT gmail DOT
> com>
> wrote:
> >
> > Oops, didn't write that the master/media server will have 4x 1 Gbit
> > NICs & 8x LT03 tape drives. Using the document I arrived at 8 CPUs &
> > 4.6 GB RAM
> >
> > Trying to get a server that can handle the NICs & tape drive at full
> > tilt & peoples experiences with using this document or other methods
> > of sizing
> >
> > Regards
> > Michael
> >
> > 2008/3/26, Ed Wilts <ewilts AT ewilts DOT org>:
> >
> >
> >
> > > On Wed, Mar 26, 2008 at 10:26 AM, Michael Graff Andersen
> <mian71 AT gmail DOT com>
> > > wrote:
> > >
> > > > We are about to replace our backup server and I have used the Backup
> > > > Planning and Performance Tuning Guide for 6.0 to size our new server
> > > >
> > > > Our server people think the sizing is wrong, more specifically that it
> > > > gives to many CPUs
> > > >
> > > > What are you experience regarding sizing ?
> > >
> > > Rule #1. There's no such thing as "too many CPUs or too much memory".
> > > Rule #2. See Rule #1
> > > Rule #3. Is your storage growing? If it is, see rule #1.
> > >
> > > In general, the master server needs lots of memory and cpu and the media
> > > servers need less memory but lots of I/O bandwidth. All of them need
> > > plenty of disk space for logs - 20-50GB at a minimum and in a busy
> > > environment while troubleshooting issues, 100GB of logs is not unheard
> of.
> > > Without significantly more details on what exactly you're trying to
> > > accomplish and what config you came up with, we're not going to be able
> to
> > > get more specific than that.
> > >
> > > .../Ed
> > >
> > > --
> > > Ed Wilts, Mounds View, MN, USA
> > > mailto:ewilts AT ewilts DOT org
> >
> >
> >
> > _______________________________________________
> > Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
> > http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
> >
>
>
>
> --
> Ed Wilts, Mounds View, MN, USA
> mailto:ewilts AT ewilts DOT org
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