Clarification of Answer by
maniac-ga
on
30 Jul 2006 13:00 PDT
Hello Dunky,
To answer your additional questions in order:
[1] When u say that software raid is suitable for all but boot disk do
you mean that you can't have the system drive mirrored (i.e. you would
need three hard drives to implement this solution, 1 for the os and
two for the mirroring) or does it mean you have to start up using a
boot disk to set it up?
Hmm. In the initial answer, I meant that software raid would:
- not be used on the boot disk
- use two disks for user data (mirrored)
and require three disks total. I was led to that conclusion from the
references I found.
In doing some additional searches, I seem to get inconsistent answers such as
http://developer.apple.com/documentation/MacOSXServer/Conceptual/XServer_ProgrammingGuide/XServer_ProgrammingGuide.pdf
which indicates that the boot disk CAN be mirrored, saying in part
"you can easily use the built-in software RAID of Mac OS X Server to
mirror the boot drive" - though it does not say HOW, and
http://docs.info.apple.com/article.html?path=DiskUtility/10.5/en/duh1013.html
which describes some limitations on boot disk partitions and RAID, and
http://docs.info.apple.com/article.html?artnum=303692
which indicates some Mac's cannot boot from a RAID volume, and then
http://docs.info.apple.com/article.html?artnum=106594
which says in part that "In server versions verions 10.1 to 10.1.4 and
client verions 10.1 to 10.2.8, RAID volumes can be used as data
volumes only - not as the startup disk on which system software is
installed. You can RAID a startup volume in 10.3 or later."
So the specific yes or no answer will vary with your OS version and
configuration. I suggest using OS X 10.3 or later and using RAID to
mirror the entire boot disk (should be a safe configuration).
2- THey are plenty of cheap raid cards on eBay, can i use them? (for
instance http://cgi.ebay.co.uk/Ultra-ATA133-IDE-RAID-PCI-Controller-Card-P06_W0QQitemZ220011717418QQihZ012QQcategoryZ96881QQrdZ1QQcmdZViewItem)?
Hmm. The link you provided did not seem to work (perhaps a session
cookie), but a search on eBay with
Ultra ATA133 IDE RAID PCI Controller Card
shows a number of inexpensive interface cards, none indicate Macintosh
compatibility. They are cheap enough that you might be able to do a
test, but I can't be sure. Doing a similar search (using Google) and
adding macintosh to the phrase brings up items such as
http://eshop.macsales.com/item/ACARD/AEC6880M/
http://www.sonnettech.com/product/tempo_raid133.html
http://www.macsense.com.au/acard_ultra_ide_mac_aec-6880m.htm
which I recognize are much more expensive, but appear to have the
compatibility you need.
3- The hard drive on the G4 uses ultra ata 66, can I speed this up?
(if i were to buy the card above which is ata 133?)
The card would likely support it (as ATA 66), but will likely not
speed up the disk transfer (the card might have a bigger cache or
other effects that provide minor improvement). If you really care
about the performance - a new drive would be needed. You could use the
old drive to do backups or store data that is not so time sensitive.
I am planning on testing your solution this week...
Great. I hope everything works out OK for you.
--Maniac
