OS X Raid 1 Mirror.

[kettle]

The question is speed and system resource usage.

Is there a system hit to sending the same data to two drives as opposed to the usual single drive?

Is there much difference in setting up a mirror raid on the same ATA bus compared to setting one up using separate ATA busses.

If it's the same data going to both drives, surely there would be the same amount of bandwidth to use?

also, what's the deal with using a raid as a startup drive. Can you use Raid 1 (mirrored) for system data, were previous restrictions just limited to earlier versions of OS X?

any light on the subject would be gratefully received.

thanks

 

[kettle]

more

oooh, found one answer myself.

It appears that 10.3 onwards can use a Raid array as a boot disk.
that is encouraging news.

This same info source told me that OS 9 could not use raid disks set up in 10.1, so a new question is...

Can OS 9 use raid setups created in 10.3?

thanks.

 

[kettle]

Partitioned Raid 1

eek

just thought of another related question...

Can the mirrored drive (raid 1) have partitions on it?

and

could a raid be created from an already established dual partitioned hard drive just by adding another new drive the same size?

or would the new drive need to be partitioned in an identical manner first and then set up as two mirrored raid arrays?

sorry for dragging this one out.

thanks

 

[crackpip]

I think the RAID can be created using partitions, you'll of course want the RAID'ed partitions to be the same size.

More importantly, however, let me warn you that my experience with the software RAID from osx has been very poor. I purchased four 80GB firewire drives to create two external RAID 1 volumes for two separate machines. After about 4 months of usage, the RAID volume would become corrupted and need to be formatted. Diskwarrior helped me to recover some of my data, but I still lost a good deal of work. My advice is get a good backup program and use the diskspace you would waste in a RAID and do automatic backups of important files.

crackpip