[Leica] RAID controllers?

[hartzell at alerce.com (George Hartzell)]

Adam Bridge writes:
 > I was wondering about LUG experience with hardware RAID controllers.
 > I'm a Mac guy and suspect that there's enough difference so that PC
 > experience doesn't translate.
 > 
 > But I'm thinking it's time to get really serious about a full RAID
 > solution. 

You don't need a hardware RAID controller on a Mac, software RAID
works great and has a couple of advantages: a RAID card is an
expensive single point of failure and if/when you do have any kind of
trouble it's easy to take the disks and plop them into another machine
without having to track down another hardware RAID card with a
compatible firmware release, wait for apple to ship it too you,
etc....

I agree with Brian and his IT community, the only thing that's not
running software RAID in my house are single-drive laptops, my Mac OS,
FreeBSD and Linux boxes all use software RAID.

Performance isn't really an issue, most machines these days have
enough horsepower that mirroring doesn't strain them and even RAID-5
is doable.  This assumes that you have plenty of RAM, if you're
swapping images out in Photoshop or something then disk performance
might be an issue.  Ditto if you're doing full motion video.

I disagree w/ Gary's statement, there's only one small reason not to
put the OS onto the RAID too.  One cute trick that you can do with a
Mac is boot it into "target disk mode", which let's it act like a
usb/firewire disk for another computer.  You can't do with with
Apple's software RAID.  Other than that, I can't see any reason to run
the risk of having to reinstall all of your stuff when/if your OS
system disk fails.

I *do* run my Mac Pro tower with a pair of 1TB disks in a software
RAID and the only thing that's slow about the system is _me_.

All that said, a mac running Time Machine to an external local disk is
really never more than an hour or so out of date, and that might be
good enough for you.  It's trivial to do a clean install from a Mac OS
DVD to a fresh disk from a Time Machine backup .

Everyone should practice it once or twice.

Here's a pointer to a brief apple article on setting up the RAID.  

  http://support.apple.com/kb/HT2559

Google will point you to more.  Pay attention to versions of OS X
(recent ones have made this easier) and OS X vs. OS X server.

If you boot off of the installer dvd, before you get going, there's a
chance to run Disk Utility from one of the pull down menus.  Do that,
set up a mirrored RAID, then go back and do the install onto the RAID.

Then, before you waste time installing all kinds of stuff, turn off
the computer, remove one of the drives, boot it up, and see what
happens.  Check out Disk Utility and see what it says about the RAID.
Shut it down again, reconnect the drive, restart it, see what happens,
check out what Disk Utility says.  Get used to how looooooonnnnnnggggg
it takes to rebuild a big mirror (hw RAID takes time too...)  Practice
it a few times.

This is a much better time to learn how to work with the RAID than it
will be when you have all of your images online and you're up against
a deadline and freaking out.  Same advice stands if you set up HW
RAID.

And finally, RAID is *not* a replacement for regular backups,
preferably rotated off site.  Time Machine makes that so simple
there's really no reason not too.  Any RAID scheme is still vulnerable
to a cup of coffee poured into the computer or a fire or theft or.....

g.