Multiple RAID 1 volumes?

[dkingofpa]

Are ReadyNAS devices able to create multiple RAID 1 volumes on a single drive?

The reason I ask is because I need to have a volume per Time Machine backup for each of my Macs. Time Machine backups grow to the size of their hosted volume. So the best way to limit their size is to limit the actual size of the hosted volume. I tried one other NAS device only to find out after the fact that they only supported one RAID 1 volume on a drive.

[PapaBear]

I don't know of any Raid device that will support multiple volumes on a single drive. Raid is basically structured to take multiple drives and put them together in a volume. Now, you could use two drives and set up two Raid0 volumes, 1 on each drive. Or, you could use four drives and do two Raid1 volumes, each using two drives for redundancy.

If you are only going to use it for backup, the redundancy is not as critical.

Some of the other members who are more familiar with Macs and Time Machine may better information.

I went the other way, and keep absolutely no data on my PC's. Once I get a system up and functional, I clone the system drive, so if I lose the drive I don't have to reinstall from scratch again. All of my data resides on my ReadyNAS with single redundancy and backed up to another ReadyNAS.

[dkingofpa]

So if I have a 2TB drive, I can't have two 1TB volumes on that drive and set up to be mirrored to a second 2TB drive using RAID 1?

[PapaBear]

I don't know of any Raid controller that will do that. They are set to combine drives into volumes, not divide them.

[mdgm]

You can use Flex-RAID and create two RAID-1 volumes however the ReadyNAS will only backup to Volume C. You can create up to four volumes, but any given disk can only be included in two of these.

Also note that a RAID-1 volume requires two drives. A single drive volume would be RAID-0 as there is no redundancy.

The ReadyNAS limits the size of Time Machine backups by setting a quota (see http://www.readynas.com/TimeMachine) which is shared between all your Macs Time Machine backups. The backups are stored on Volume C. On Sparc ReadyNAS (e.g. Duo, NV+) you can set a limit up to 2TB and on x86 ReadyNAS (e.g. Ultra, Pro) I think you can set whatever limit you want now.

The use of a quota is much simpler than trying to use multiple volumes and allows you to grow the space allocated to Time Machine independently of your drive upgrades.

I would recommend you purchase a ReadyNAS Ultra or ReadyNAS Pro. These support 3TB drives, have fast Intel CPUs and are much faster than Sparc ReadyNAS (have which have slow Infrant Sparc CPUs). x86 ReadyNAS (e.g. Ultra, Pro) are much more future proof.

Also note that NetGear ReadyNAS have the best AFP and Time Machine support: http://www.netafp.com/status-of-netatalk-and-afp-support-by-nas-vendor-322/

Whilst there is no support for Time Machine backups from Macs running the soon to be released Mac OS X 10.7 Lion yet, NetGear being a funder of Netatalk development is a clear indication that they intend to provide this support.