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I have two 14TB external disks and want to run a Time Machine backup to one and have the other be a duplicated backup. I created a RAID 0 using Disk Utility but to my surprise the duplicated backup disk has disappeared from my desktop. I can see it in Disk Utility but how do I know if the backup is working correctly when I can't see it. Thanks for any help!
iMac 27″, macOS 10.13
From what you’ve said it sounds like you’ve not fully understood the differences between RAID formats? No offence intended.
By using RAID 0 (Stripe) you’ve effectively created one 28TB single volume with no fault tolerance or redundancy. Effectively giving you the opposite of what you want.
You need RAID 1 (Mirror).
This results in a one single volume of 14TB. Every time you back up, data is written to both volumes. If one volume in the set fails, your data is still ‘safe’ on the other one. With RAID 1 you’ve the facility to replace the failed drive in the set and your precious data will be rebuilt. With RAID 0 you get none of that. With RAID 0 if one drive fails all data is lost.
RAID 0 offers performance with no redundancy. RAID 1 offers redundancy with less performance.
If it was me I would not bother with RAID and use Time Machine on one volume and Carbon Copy Closer on another. Buy a 3rd one and use that for redundancy for one of the other two volumes as a just in case. Alternate it between the two.
Good luck.
From what you’ve said it sounds like you’ve not fully understood the differences between RAID formats? No offence intended.
By using RAID 0 (Stripe) you’ve effectively created one 28TB single volume with no fault tolerance or redundancy. Effectively giving you the opposite of what you want.
You need RAID 1 (Mirror).
This results in a one single volume of 14TB. Every time you back up, data is written to both volumes. If one volume in the set fails, your data is still ‘safe’ on the other one. With RAID 1 you’ve the facility to replace the failed drive in the set and your precious data will be rebuilt. With RAID 0 you get none of that. With RAID 0 if one drive fails all data is lost.
RAID 0 offers performance with no redundancy. RAID 1 offers redundancy with less performance.
If it was me I would not bother with RAID and use Time Machine on one volume and Carbon Copy Closer on another. Buy a 3rd one and use that for redundancy for one of the other two volumes as a just in case. Alternate it between the two.
Good luck.
Antonio,
Thanks for the quick response! Thanks for the clarification, that makes perfect sense from what I'm seeing. I've been playing roulette with my data far too long and now I can feel a little more at ease.
If you want a RAID backup drive, then there are small USB external drives that have a hardware RAID or you can look at a NAS option which is compatible with Time Machine such as Synology which is especially useful if you have multiple systems. A hardware RAID is risky if the enclosure breaks as you need an identical model enclosure to move the drives to in order to access their data. The Synology NAS uses a software based RAID approach which also includes data scrubbing to ensure the integrity of the data.
The more important the data the more backups/copies you should have.
Glad I could help.
For the benefit of others who may read this post I should add a RAID is not a back-up. Too many make the mistake in thinking it is. Furthermore any RAID is at its most vulnerable whenever a drive fails in that RAID set.
When making a RAID 0 one of the disks disappeared
