SOLVED Re: do I need to do something special to use more than 4 Gigs under Feisty?

[Gavin McCullagh]

Hi,

On Thu, 31 May 2007, john  wrote:

> The bullding have a mult-imode fiber backbone and right now the LTSP
> installations are on separate vlans. If I get this really working well
> I may make a new "ltsp vlan" and dedicate a strand to it.

I see!  Forget I said anything then :-)

> >   - If your server fails (eg motherboard failure), what happens?  Do you
> >     have a fall back server ready to swap back in?
> Currently I do, but in the next round, with a larger, more expensive
> server, I probably won't. I would probably just replace the Mobo as
> fast as I could get a new one. Possibly a bad idea, let me think about
> that....

Once you're thinking about it, I guess that's the main point.  If you were
unlucky, you could have several days of downtime.  I appreciate a
motherboard dying is a very extreme case but a RAID controller dying is not
unheard of.

There is some advantage to having two lesser servers load-balanced in that
when one falls over the other can keep going (perhaps slowly, but that's
better than nothing).  Could you just keep your existing machines around?

> > > 2) Do I need a "real" server doing RAID 5 or whatever for the LDAP Backend
>   RAID10
> > is expensive but seems like the ideal solution.  RAID5 will give you some
> > performance increase and some limited redundancy, but it's limited.
> Do you think I can get away with something like a pcix based raid
> controller like this?
> 
> http://www.newegg.com/Product/Product.aspx?Item=N82E16816118086

I'm not an expert on specific components, but there's some stuff about
choice of raid and disk technology here:

https://help.ubuntu.com/community/EdubuntuDocumentation/EdubuntuCookbook/HardwareRequirements

and some more detailed stuff on the LTSP site which was written by the
original LTSP guru:

http://wiki.ltsp.org/twiki/bin/view/Ltsp/ServerSizing

"SCSI drives and controllers are the gold standard for servers, and if you
are planning more than about 20 terminals, then you should definately
consider nice fast 15k rpm drives connected to a SCSI RAID controller."

Your call obviously, but it's worth bearing in mind.

Gavin