> > > database server, a lot of ram will be required for fast operation. I was
> > > thinking at a minimum 256 meg of ram. I also want to have the database run
> > > on a RAID 5 array for speed and fault tolerance. Any suggestions here for
> > > disk type, RAID scheme (software or hardware), controller type, etc.? Any
Obviously, memory needs vary according to what apps are running. On my linux
RH6.0 system, I'm finding that pgsql backends take ~4Mb each. Seems like I need
something near ~100Mb for overhead (X server-20Mb, netscape-40Mb, xterms-10@4Mb
each). For apache with 30 child processes @ 25Mb each (mod_perl with lots of
cached data and lots of modules), that quickly adds up to a gig of ram to avoid
performance-killing swapping.
> > my preference tends to be software raid...whatever I've ever seen as far
> > as hardware raid is concerned has been quite slower then software
> > raid...and this is with high-end servers...
>
Jeff Hoffman wrote:
> ...i have seen several places which told me
> that software raid under linux _isn't_ safe for multiprocessors & no
> place has told me for sure that it is.
Would you mind clarifying your understanding on which versions of linux are unsafe
for software raid and how? Browsing deja, RH 6.1 (2.2.12-20smp) reportedly handles
software raid without known problems (other than less than glowing documentation
reviews), and I'm setting up pgsql/apache on such a system with software raid (no
clear showstopping problems yet).
Thanks,
Ed Loehr
