What to do post-RAID in El Capitan?

Mirrored or striped or something else?

Using the RAID Card or Disk Utility RAID or something else?

Ah, so your Backup is not lost. The RAID is broken, but either drive can provide a decent Backup, they just can't work together any more.

If you feed the two separate drives to Time Machine, it will automatically alternate drives on every other backup. That is actually a much better setup, because if it makes an error, it does not make it in duplicate -- each copy is a little bit different internally.

I think if it were mine, I would erase one of the drives, and give it back to Time Machine and let it alternate with the original RAID Drive. That is what I use with my Home Server, and it seems to work well.

...I've read that Apple has deliberately removed this, so it's a feature, not a problem. ...

RAID support has only been removed from the Disk Utility GUI

RAID arrays can still be configured via the command line version diskutil

from Terminal.

Before doing anything, you may want to check via diskutil whether the drives are still in fact

configured as RAID. It may be there is some bug in the GUI that shows RAID volumes as

independent drives.

In Terminal, simply type diskutil and enter to find all the command "verbs" and options are.

Even in the with the old version of Disk Utility, there were still command line options available

that weren't in the GUI.

FWIW, what I would do instead of having Time Machine writing to a RAID, I would continue to

use one drive for Time Machine and use the other drive as a bootable system clone. Having

the bootable clone can get you back up and running immediately should something happen

and allow to fix things at a later time. Also, doing a full system restore from a clone can usually

be faster than using Time Machine. Time Machine would then be used for a quick restore from

smaller incremental change issues or the "Oh crap I deleted my project!!".

I am set up to have Time Machine do its thing hourly/daily/etc. and do incremental weekly backups

to the clone.

If your RAID is still working typing this command in Terminal will tell you the status:

diskutil AppleRAID list

Usage: diskutil [quiet] appleRAID|AR <raidverb> <options>,

where <raidverb> is as follows:

list (Display the current status of RAID sets)

create (Create a RAID set on multiple disks)

delete (Delete an existing RAID set)

repairMirror (Repair a damaged RAID mirror set)

add (Add a spare or member disk to an existing RAID)

remove (Remove a spare or member disk from an existing RAID)

enable (Convert a volume into a single disk RAID set)

update (Update the settings of an existing RAID)

diskutil appleRAID <raidverb> with no options will provide help on that verb

---------

diskutil AppleRAID list

AppleRAID sets (1 found)

===============================================================================

Name: SrvDrv1T

Unique ID: 197AE52F-76AF-4AEE-95BE-0ADC970EAB32

Type: Mirror

Status: Online

Size: 999.9 GB (999860895744 Bytes)

Rebuild: manual

Device Node: disk3

-------------------------------------------------------------------------------

# DevNode UUID Status Size

-------------------------------------------------------------------------------

0 disk0s2 2311A3F3-3439-431C-9411-0C22D401D939 Online 999860895744

1 disk1s2 13266F2A-4E90-4870-A654-BAED2CEC636C Online 999860895744

===============================================================================

$

I just think that removing it after its been in OS X since before tim cook being a CEO, and all of sudden they have taken it off from OS X and as of today using terminal is archaic. for many of us users that needs things quick and done typing all this mumbo jumbo, really, does not make any sense do you type terminal commands in your iPhone or iPad. Really OS X is heading towards backward instead of forward.

I think OS X is heading backwards to archaic times instead of forward. it was working perfectly find doing raid and using the burner feature. but all of that is gone.... really I don't know what tim cook is doing.

<Edited by Host>

Apple has not provided any specific guidance (that I have seen) about why it was removed from the GUI.

I can only speculate that Apple decided RAID was an advanced feature, or that too many inexperienced Users were getting themselves in trouble using it, and removed it from the mainstream by removing the GUI interface for it.

Now you really have to want it -- you have to use Terminal to set it up.

AS we speak I am retroverting to Yosemite just because El Capitan is not as advance as to an OS should be, but all I could say why take the burner feature also, many people are having problems with the SuperDrives also. Now that is true they are not installing SuperDrives onto the new mac computers and one of the reason why I have a data doubler where my SuperDrive use to be with, one terabyte ssd and with another 1 terabyte ssd in the hdd bay and with a raid 0 array which gives me a max 2 terabyte and a blazing speed new iMac for more years to come and for sure I won't be updating to no new OS further more if it works why update the OS.

The procedure is slightly different from your assumptions. The RAID can only be rebuilt onto a Blank or Spare drive, not one that contains data, even if failed. (disk2s2 is listed as failed.)

A mirrored RAID can be repaired ONCE by erasing the drive listed as failed, then either declaring it a spare or manually adding it back into the RAID, then having the RAID rebuild if it does not do so automatically. (Rebuild can easily take all afternoon and most of the night, but you can quit the Utility once it starts to rebuild and it will proceed, slowly, in the background.)

If you have to rebuild it more than ONCE, that drive is not good enough to trust with RAID data, and a new one should be used instead.