Soft RAIDs and El Capitan

Loa

macrumors 68000
Original poster
May 5, 2003
1,587
45
Québec
Hello,

I've been using a soft RAID0 set (two 2TB black drives) ever since 10.8, and it has been working flawlessly hasn't failed or been rebuilt in years). It's currently in a two 2TB volumes set-up, one fast and one slower.

I want to erase it and reformat it in a 3tb and 1tb setup, but I fear that Disk Utility's not what it once was. Can it still handle soft RAIDs like it used to?

Loa
 

ActionableMango

macrumors G3
Sep 21, 2010
9,263
6,250
I want to erase it and reformat it in a 3tb and 1tb setup, but I fear that Disk Utility's not what it once was. Can it still handle soft RAIDs like it used to?
RAID is gone from Disk Utility. It's still in OS X, but you have to use the command line now. There may be third party apps providing a GUI, but I wouldn't know.
 

Loa

macrumors 68000
Original poster
May 5, 2003
1,587
45
Québec
Oh... That's such a shame. I don't want to use third party software. I'll try and see if someone made a GUI front end to the native app.

Thanks
 

\-V-/

Suspended
May 3, 2012
3,151
2,619
Yes ... I just love when Apple silently removes crucial functionality that I use from OS updates.
 

AidenShaw

macrumors P6
Feb 8, 2003
18,078
4,142
The Peninsula
Yes ... I just love when Apple silently removes crucial functionality that I use from OS updates.
Why are you complaining, doesn't Apple warn you a couple of versions in advance that crucial systems are deprecated?
[doublepost=1461031066][/doublepost]
To get RAID set up.
"Why should you have to do that" meant "why did Apple remove mainstream features from the OS without warning", and force you to boot into standalone environments to do simple setup tasks.

Or, maybe Apple is getting you ready for the "OS Phone Pro OS 11 for Workstations" to be announced at MacWorld SF Spring 2016. I hear that it will even support filesystems on 64GB SD cards, for those of you with really, really huge files.
 
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h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
I didn't use software RAID anymore. But is the current disk utility able to re-distribute the partition (is the pie chart adjustable?)? Of course it can't do any RAID stuff, but you just want to re-partition your 4T RAIDed partition into 1T and 3T, no need to touch the RAID itself if the current disk utility see it as a adjustable single 4T partition, right?
 

nigelbb

macrumors 65816
Dec 22, 2012
1,019
188
How smart is Apple's RAID software? RAID0 or RAID1 is normally predicated on equal size disks & if they are not equal size then the RAID set will be sized at 2 x the smaller disk. So in the OP's case this would mean a 2TB RAID0 set not a 4TB. Even were the software able to handle odd size disks a 3:1 ratio would mean that there would be little performance advantage to setting them up as RAID0. The extra performance of RAID0 is potentially 2 x performance of a single disk because reads & writes get executed in parallel. If the data is distributed 3:1 then performance will be somewhat unpredictable but definitely a lot less than double that of a single disk.
 

h9826790

macrumors G5
Apr 3, 2014
12,768
5,579
Hong Kong
How smart is Apple's RAID software? RAID0 or RAID1 is normally predicated on equal size disks & if they are not equal size then the RAID set will be sized at 2 x the smaller disk. So in the OP's case this would mean a 2TB RAID0 set not a 4TB. Even were the software able to handle odd size disks a 3:1 ratio would mean that there would be little performance advantage to setting them up as RAID0. The extra performance of RAID0 is potentially 2 x performance of a single disk because reads & writes get executed in parallel. If the data is distributed 3:1 then performance will be somewhat unpredictable but definitely a lot less than double that of a single disk.
OP can partition each of the HDD to 0.5T + 1.5T. And then RAID the smaller partitions to a 1T RAID 0 array, and the bigger one to a 3T RAID 0 array.
 

AidenShaw

macrumors P6
Feb 8, 2003
18,078
4,142
The Peninsula
How so? I was offering an alternative on how to set up a RAID array.

Why you jumping on me? Why don't you go and attack Apple for whatever displeases you?
Sorry if I came across as attacking you.

I was a bit annoyed that your message was "do this in terminal to get RAID", and not "do this in terminal for RAID - for now, until Apple rips out the underlying support and you're screwed".

Seriously - this post screams "get rid of Apple software RAID as soon as possible, before it completely disappears". Surely taking it out of disk utility should worry anyone using it.... Worry them a lot.
 

pastrychef

macrumors 601
Sep 15, 2006
4,520
1,017
New York City, NY
I have no idea what Apple's plans for the future are. I am not defending their neutered Disk Utility. I miss the old Disk Utility as much as everyone else.

I was just trying to give the OP suggestions on how to get his RAID going the way he wanted.