Setting up your RAID Volumes
SoftRAID 3 lets you create 3 types of RAID volumes:
1. Non-RAID, or standard, used the same as standard Apple volumes,
2. RAID 0, or Stripe Volumes, used for high speed data access with video, audio and graphics applications,
3. RAID 1, or Mirror Volumes, used for instantaneous backup and offsite archiving.
Non-RAID and Mirror volumes can both contain Mac OS X and be used as startup volumes on PowerPC and Intel Macs.
The disks which are part of SoftRAID volumes can hold one or more SoftRAID volumes shared with other disks.
For example, you may have 3 disks, A, B, and C. You can have a SoftRAID Stripe volume using 1/2 the free space
of all the disks, a Mirror volume which takes up 1/3 the free space of disks A and B, and then your non-RAID
startup volume can be on disk C.
If you are converting an Apple non-RAID volume to a SoftRAID volume, it will
take up the entire capacity of the disk. To avoid this, you can copy your data to another disk, reinitialize the Apple disk with the
SoftRAID driver, create new volumes of a more appropriate size and then copy back on your data.
Designing a RAID system
RAID 0 - Stripe Volumes
The key for setting up a RAID 0 volume is to pick similar, fast, reliable disks and only use the first half of the disks for the RAID 0 volumes. The rest of the disks capacities can be used for non-RAID or Mirror volumes. In general, the more disks used, the faster the reading and writing of the data. The performance of your Stripe volume depends on which buses and disks you use. For more information read RAID Scenarios and Stripe Essentials in the SoftRAID 3 manual.
RAID 1 - Mirror Volumes
Setting up a RAID 1 volume depends on what type of backup you need:
Instantaneous Backup
To be protected in the event of catastrophic disk failure, you will want to build a Mirror volume, which can be a startup volume, which contains at least two disks. In the event that the Primary disk fails, SoftRAID will switch to another disk automatically, designate it as the Primary disk and allow you to remove the failed disk.
Offsite Backup
If you want to maintain an offsite backup of your volume, you will want to create a Mirror
volume with at least three disks. This allows you to store one of the disks offsite in a secure
location while the other two are used with the Mac. When you want to update your offsite backup,
you can remove the secondary disk from your operating Mirror volume and switch it with the disk
which was stored offsite. SoftRAID will then rebuild the disk you just attached, in the background,
while you continue to use the Mirror volume.
Server Archive
If you cannot easily backup your server volume because it needs to be available 24 hours a day and 7 days a week,
you can create archives using a SoftRAID Mirror volume. Depending on how many archives
you want to store offsite, you can choose disks or tape as your archive medium.
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