Raid?

A

AJaX

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I got a question about the RAID option under the disk utility in os x....the option looks very promising, i have two 75 gig IBM GXP hard drives and am wondering if anyone else has raided their drives...is it fast and does it seem like they are both one hard drive? Thanks!
 
A few things I know about RAID, fraid I can't say what it's like in OS X in particular though

SCSI disks make RAID reallllly fast. IDE drives would probably be a bit faster, but not by as much.

Yes, it does look and act like just one disk.

I can't fool around with disk utility, I'm afraid - that app, and NetInfo Manager, always crash for me. Go figure. Anyway, I therefore don't know what level of RAID Apple offers. Check out this page for a better explanation than I could give of what the levels mean.

I'm not sure what levels you can get with only two disks, though I'm pretty sure not all of them.
 
One thing I forgot to mention - with anything but RAID 0 (which, as the link mentions, isn't strictly RAID, more a 'convenience' to make it look like you have a really big fast drive), you'd pretty much need a whole drive's worth of check information (redundancy), so you'd be down to 75 GB of total storage. You'd never lose anything to a HD crash though.
 
Also dont forget that RAID can slow down you writes, and because your using IDE drives it will decrease the performance of the system. My suggestion is to just have them both as 1 volume (if 1 disk goes they both go) or keep them seperate and invest in a sancube or some scsi disks.

If you want to get serious about fast storage then you cant go past a sancube

http://www.sancube.com/

:)

If only I had the money, 22inch cinema display (2 of them) and a sancube..
 
Originally posted by scruffy
SCSI disks make RAID reallllly fast. IDE drives would probably be a bit faster, but not by as much.
Click to expand...
There is NO way an IDE RAID will outperform a SCSI raid with similar drives of capacity and speed. Actually you can get faster IDE drives and it still won't outperform a SCSI raid.
This is especially true in Windows NT, where an IDE requires so much more processor power to function as compared to SCSI.
SCSI is also asynchronous, where as IDE is not.
Use RAID 5, which requires at least 3 drives, as one is used just for parity.
Using RAID 5 will significantly increase your write speeds, as the information is written across several disks in smaller pieces and in parallel as opposed to writing all data to one drive.
 
I have a 2 port 100G Sancube. In OS 9 I had no problems. Now that OS X.1.1 is my main OS I am unable to write anything to the drives. Also, I cannot create folders, delete or execute, even though I have assigned my username full access. I have two hours of Unix under the belt and have figured out that the Sancube belongs to user root and group:wheel. Do I have to log in as root and add my Username to the group:wheel?
Or is is possible to get rid of the MicroNet Sancube drives and have OS X Disk Utility assign the mounts and permissions.
By the way, I tried using Super Get Info to make these changes, which only gave me a -5000 error.
 
Log in as root and change permissions access from there. Can you access the "Ignore Privileges on this volume" using the Get Info command ?
 
I have not had experience with the specific IDE raid you mentioned, but have had some with others. An IDE raid 5 installed in a 500mhz PeeCee did not even come close to a single 7500rpm SCSI-2 drive of the same size. It was easily 30-40% less capability in performance of the SCSI. If you want RAID, think SCSI, otherwise save your money. The non-asynchronous nature of IDE negates the speed gained from a RAID. IMHO
 
I purchased 2 60GB 7200RPM disks for my 533 G4 in order to set up an internal RAID 1. My intent was to divide my disk into 3 partitions (one for X, one for 9 and one for other stuff)and then have these 3 partitions mirrored on the 2nd disk. Come to find out the boot disk cannot be under RAID control. I cannot belive this is not possible. Having the root disk mirrored is vital for the R (redundancy) in RAID!! How is the system redundant if it can't even be booted after a disk failure???

Can someone explain this to me?
 
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