Disk Utility & Mirrored RAID

I have a 250 Gb drive installed in a G5 and want to add another and mirror the first. In setting up the mirrored set, will the first drive be erased, or will the second drive just be updated to reflect the first?
Thanks

Has to be erased. Apple Disk Utility won't allow you to do that.

Similar Messages

Disk Utility : Partition / Raid or Raid / Partition ?

I have two external USB drives that I'm attempting to set up using Disk Utility.
I'd like to create either
- one RAID1 set with two partitions, or
- two RAID1 sets with one partition
however I'm not having much luck with either option. Is either scenario possible?

After some experimentation, I seem to have come up with a kludge ...
Partition both disks into identical volumes (A1 = B1, A2 = B2)
Using Disk Utility :
- create RAID Set 1 ( A1 + B1 = RAID1)
- create RAID Set 1 ( A2 + B2 = RAID2)
Error message 'Creating RAID set failed'
Restart ...
Using Disk Utility :
- click on partition A2 (now renamed RAID Slice)
- Erase partition
Upon erasing the partition / RAID slice will remount and the Disk Utility should show two RAID sets. A cursory examination of each RAID set's behavior leads me to believe it is simply a bug in Disk Utility that prevents the creation of two RAID sets on the same disk pair.

Disk Utility / diskutil RAID Mirror rebuild fails: mistakenly thinks disk is too small

Has anyone else had this issue?
I've just migrated my Lion Server install to a slightly upgraded Mac Mini running Mavericks and am running into horrible trouble rebuilding my Apple RAID disk, which I established on Lion and would like to repair using Mavericks. The drives being used are the same units; the RAID got out of sync due to a power outage, and rather than wait to migrate until the old machine was done rebuilding the array like a week later, I just figured I could repair the RAID after migration.
Not so, however. Disk Utility, when I attempt to rebuild the raid using the second drive, tells me that it is too small.
When I look in diskutil, here's what it shows me:
<blockquote>
/dev/disk2
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *3.0 TB     disk2
   1:                        EFI EFI                     314.6 MB   disk2s1
   2:         Apple_RAID_Offline                         3.0 TB     disk2s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk2s3
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *3.0 TB     disk3
   1:                        EFI                         209.7 MB   disk3s1
   2:                 Apple_RAID                         3.0 TB     disk3s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk3s3</blockquote>
Notice that the EFI partition on disk3 -- the intact RAID slice -- is the correct size, 209.7MB or 200MiB. The EFI partition disk2, however, which was created moments earlier by Disk Utility in its failed attempt to rebuild the array, is 100MiB too many. As a result, the Apple_RAID partition is about 100MiB smaller than the one on disk2. Hence, this error.
So my question is: what the **** is going on here, and what can I do about it? Is this just a Mavericks bug, that it creates EFI partitions of the wrong size? The disks are seen as identical in diskutil. Is there anything I can do to rebuild my array?
I've considered rebuilding it on the old server, but then next time it gets messed up I'm just going to run into the same problem, as whichever slice fails will have a correctly-sized EFI partiton, and if Disk Utility insists on creating an incorrectly-sized one during the rebuild process it's just going to fail again.
Please halp! Thank you!

OK, so here is the solution for my problem
what i did was the following:
- as i wrote before, i erased the disk with command line (diskutil zeroDisk disk1), then the pending sector was gone.
- i decided to rebuild the raid in recovery mode to prevent further system crashes. so i added the previously zeroed disk1 to the degraded raid. when disk utility finished adding the disk it stalled but showed the raid ONLINE. so i decided to hard shutdown my mac mini - because it wasn't possible to restart via the interface of the recovery mode.
after staring the mac the system loaded and everything was working again properly! including disk utility still showing raid1 online.
btw, time machine was working correctly again when i deleted the .inprogress-file on the backup-disk.
maybe someone else is able to use this information - that would be great!

Disk utility says "RAID STATUS: Disk missing"?

When I boot up OS 10.3.9 there is error message "detected volume OS X cannot read - initialize, ignore or eject" - then it dissappears and the system drive behaves normally. But in disk utitlity it says "RAID STATUS: Disk missing".
The disk is not partitioned and it will not let me repair permissions. Any ideas?

Disk Utility monitors the status of the disks in a RAID set. If you see a message indicating that a disk is missing or has failed, try these troubleshooting steps:
If you are using a striped RAID set, delete the damaged RAID set. Your data may be lost. Be sure to back up your RAID sets and other data regularly.
If you are using a mirrored RAID set, there may have been an error writing data to the disk. Click Rebuild in the RAID pane of Disk Utility.
If a problem persists, replace the damaged disk and click Rebuild to rebuild the RAID set.
Use the First Aid pane to repair the RAID disk, then check the RAID set to see if it still reports an error. If the problem is still present, quit and reopen Disk Utility, select the RAID disk, and click RAID. Check the RAID set to see if it still reports an error. You may need to restart your computer.
iBook G4 Mac OS X (10.3.9)

Disk Utility Software RAID

Hi everyone,
I know how to create a Software RAID in Disk Utility. Let's say I do that with 2 identical FireWire drives. What happens or is the best practice when one drive fails? Will shutting down everything and then exchanging the bad drive with a new one issue an automatic rebuild like Hardware RAIDs can? Or will I have to rebuild it manually somehow? What if the RAID is the boot volume, will that make any difference in the procedure?
Does anybody have experience with this and would like to share it?
Thank you!
Björn

Hi, I am a bit confused. I just set up a mirrored RAID array with to Firewire 800 drives using two 500GB drives. Under the options button in the RAID setup was a box that you could check to automatically rebuild the array. Will this not do the job if one of the drives fails?
Also, I have set Time Machine to use this as its backup drive. It is much faster to update than using the Time Capsule drive and cuts down on the local network traffic a lot. An added benefit seems to be that the files are written just like files on any other drive and are also accessible using the Finder.
One last question. Do you know of any cons to this arrangement? I know using a RAID array for this is probably not really necessary, but I had the drives so I figured why not try it. Anyway, thanks in advance for your time.

Failed Disk Utility Software Raid

My external RAID hasn't been mounting as easily as normal so I opened Disk Utility to repair disk or whatnot and it shows one drive as failed. Not sure what this means or how I should proceed. I'd be surprised if that drive is dead. What does the Rebuild button do? I have backed up all the data on the mirror, but am not sure how to proceed. I'd like to keep this info on the RAID if possible.
Dual2 G5 & Powerbook G4 Mac OS X (10.4.4)

From Disk Utility's Help:
A disk in a RAID set has failed or is missing
Disk Utility monitors the status of the disks in a RAID set. If you see a message that a disk is missing or has failed, there are several things you can try to solve the problem.
If a disk is missing, make sure it is connected to power and turned on, and that it's connected to your computer. If you are using a FireWire or USB disk, you may need to disconnect it then connect it again.
Use the First Aid pane to repair the disks in the RAID, then check the RAID set to see if it still reports an error. You may need to unmount the RAID set to repair the disks.
In some cases, you might need to quit and reopen Disk Utility or restart your computer and then check the RAID set.
If you are using a mirrored RAID set, there might be an error while writing data to the disk. Click Rebuild in the RAID pane of Disk Utility.
If you are using a striped RAID set, delete the damaged RAID set. Your data may be lost. Be sure to back up the disks in your RAID set and other data regularly.
If you have a persistent problem with a disk in a mirrored RAID set, you may need to replace it. After you replace the damaged disk, click Rebuild to rebuild the RAID set.[/i[
G4 450 MP Gigabit Mac OS X (10.4.7)

Disk Utility - delete RAID killed data on drives before server install

OK. Here's the scenario.
I had a Dual 1G G4 with a fully functioning RAID 1 installed. So I attempted to do an install of Leopard Server. It came up with a message that said something like "OS X could not prepare disk for installation." After reading some forum posts, one guy said that he was able to install Leopard by deleting the RAID, thus splitting the RAID into two volumes. So I booted from the DVD again, and this time it reports that the RAID is degraded, and that the second drive in the RAID set is a "spare."
This seemed odd, but I figured if I delete the RAID set it would keep the section that had all the good data on it. That's when my world went to ****.
Once it deleted the RAID set, and the message came up prompting me that I would NOT lose my data, it went ahead and deleted all my data. Perhaps replacing the good volume with the so-called spare. So I have been trying in vain to get the data back. The one product that I own, DiskWarrior, does not see the drives as volumes. So it won't work. Anyone have any ideas?
There was not a LOT of data on the drive, but there was a lot of complicated web shares and a few IMPORTANT websites that I need to get back. And, yes, I do not have a current backup of the volume. I was riding the RAID 1 cushion way too hard.

It would seem that I have the answer, and I believe that this is a MAJOR problem that Apple should address with some kind of warning to its customers. The RAID set I deleted was an Apple RAID 1.0 set. Upon reading further into the documentation, I see that RAID 2.0 sets can be deleted, and the volumes split into two. But with RAID 1.0 sets, the data is lost when you delete a volume.
So, even though I was deleting the set in 10.5, it seems to have applied the rules for RAID 1.0.
http://docs.info.apple.com/article.html?path=RaidUtility/1.0/en/s1ru11.html
I am hoping that there is a way to recover my data, but i'm not too hopeful.

How to enable Staggered Spinup for DIsk-utility Software raid?

I have a Mac Pro 3, 1 (early 2008) and was wondering if the system supports staggered spin-up. I have four 7200.12 Barracudas in the drive bays and use them for software strip volume via SoftRAID.
If the system does support staggered spin-up, how can I enable it. I was previous user of Bios operated hardware, (PC user is misleading :-p) so I am not familiar on how to enable those options on Macs.

Unless SoftRAID does something, but there ARE disk drives that by themselves will I am pretty sure, whether it also depends on the controller, not sure.
I know some external RAIDs used drives that did (Maxtor had) and sometimes a disk wasn't ready on time. And tweaking the driver or firmware for the controller can help.
On a PC you can add a delay in the BIOS to wait, yes.
The whole idea is so that you aren't requesting 4-5 drives pulling the amps/watts needed at once making it lighter load on PSU.
Is there a problem? have you asked the excellent, quick and helpfull SoftRAID support? or just "curiosity?"

Using Disk Utility for RAID setup?

I just purchased 2 1TB Seagate Hard Drives 32mb cache 7200prm that I want to setup a RAID 0 (striping I believe) for Final Cut Pro for rendering. Well I also have a 3rd drive that is identical, question is does more drives in that RAID setup mean faster performance? 2 drives vs 3 or 4, etc.? Also what do you think that actual difference in reading and writing would be approximately?

You can find the max sustained, the average I/O, and minimum. From reviews and Seagate product spec details. There is some overhead for each drive as you seek and assemble the parts of a file.
The burst rate of the drive is likely around 135MB and average of the outer half a solid 100MB/sec.
The bandwidth in the Mac Pro totals 1GB for all drives, even though each is supposed to have 3Gbps.
SSDs are fast catching on for speed and fast system drives, even in stripe raid.
Don't mix 7200.12 with .11s or even different model/series/firmware. And Seagate has had its hands full with firmware issues for years, going back to the intro of SATA actually.
If you want one large volume and if having 200MB/sec matters or helps, you might want to RAID, even partition each drive first to 3/4 level and stripe that 3/4 together to guarantee 200MB/sec range.
But experiment for a couple weeks first.

Disk Utility RAID Issue

I'm trying to determine if the problems that I'm encountering are a software issue or a hardware issue.
I'm setting up a Mac Pro with Leopard and have four Maxtor 6G160E0 160GB hard drives that I'm trying to set up as two Mirrored drive sets. Everything seemed to go fine, created the two mirror sets, installed Leopard, configured and tested two user accounts and Office 2004, then updated everything to the latest version. When done I shut it down planning on moving it to it's final home tonight.
But, when I turned it on both mirror sets were degraded - all four drives were still recognized as RAID slices but came up as failed in the RAID tab. I saw no errors reported in the log so I assumed that those two drives were faulty. I shut down, moved the good drives to bays 1 & 2 and rebooted.
First reboot gave me a prohibition symbol instead of the usual Apple. Powered down and on and it booted fine but the second drive came up as a failed RAID slice. Rebooted again and both were fine.
I reinstalled the two "failed" drives and reformatted them - both reformatted fine and mounted without problems. I unmounted the new partition just in case, but, when I tried to rebuild the RAIDs I get the following in the error log:
11/1/07 7:26:00 PM Disk Utility[141] Preparing to erase : “Untitled”
11/1/07 7:26:00 PM Disk Utility[141] Partition Scheme: GUID Partition Table
11/1/07 7:26:00 PM Disk Utility[141] 1 volume will be created
11/1/07 7:26:00 PM Disk Utility[141] Name : “Untitled”
11/1/07 7:26:00 PM Disk Utility[141] Size : 149.1 GB
11/1/07 7:26:00 PM Disk Utility[141] Filesystem : Mac OS Extended (Journaled)
11/1/07 7:26:00 PM Disk Utility[141] Creating partition map.
11/1/07 7:26:03 PM Disk Utility[141] Formatting disk1s2 as Mac OS Extended (Journaled) with name Untitled.
11/1/07 7:26:06 PM Disk Utility[141] Erase complete.
11/1/07 7:26:12 PM Disk Utility[141] Unmount of “Untitled” succeeded
11/1/07 7:26:31 PM Disk Utility[141] Rebuilding RAID
11/1/07 7:26:31 PM Disk Utility[141] Filesystem: Mac OS Extended (Journaled)
11/1/07 7:26:31 PM Disk Utility[141] RAID type: Mirrored RAID Set
11/1/07 7:26:31 PM Disk Utility[141] RAID set name: “Yorktown”
11/1/07 7:26:31 PM Disk Utility[141] RAID set status before rebuild: “”
11/1/07 7:26:31 PM Disk Utility[141] RAID chunk size: 32K (default)
11/1/07 7:26:31 PM Disk Utility[141] Mirror Auto Rebuild: Disabled (default)
11/1/07 7:26:31 PM Disk Utility[141] 2 members
11/1/07 7:26:31 PM Disk Utility[141] RAID Slice (disk0s2) - Online
11/1/07 7:26:31 PM Disk Utility[141] Maxtor 6G160E0 Media (disk1) - New
11/1/07 7:26:32 PM Disk Utility[141] Error rebuilding RAID: Unrecognized Filesystem.
11/1/07 7:26:33 PM Disk Utility[141] RAID failed: Unrecognized Filesystem.
I'm at a loss at the moment. I am leaning towards bad drives, but FOUR bad drives all at once is suspicious.
I've searched for similar issues and found none so I thought I'd check here and see if anyone had any ideas.

G'day Zeekm,
Thank you for that. I did this and it seems to work. The Disk Utility GUI does not seem to work.
Hope this helps some one,
#Checked the RAID status
root# diskutil checkRAID
RAID SETS
===============================================================================
Name: Server_HD
Unique ID: 7E31E20E-F53D-4D76-AD37-139C4E1440AB
Type: Mirror
Status: Degraded
Size: 1000070610944 B
Device Node: disk2
Apple RAID Version: 2
# Device Node UUID Status
0 disk1s3 BAC72F86-B05F-4B0F-97D3-58A6207E7DFA Failed
1 disk0s3 2BFB55BB-EFF9-438C-A1F9-A8ED7A93D385 Online
===============================================================================
#Told it to resync
root# diskutil repairMirror disk2 disk1s3
Note: Syncing data between mirror partitions can take a very long time.
Note: The mirror should now be repairing itself. You can check its status using 'diskutil listRAID'.
temp:~ root# diskutil listRAID
RAID SETS
===============================================================================
Name: Server_HD
Unique ID: 7E31E20E-F53D-4D76-AD37-139C4E1440AB
Type: Mirror
Status: Degraded
Size: 1000070610944 B
Device Node: disk2
Apple RAID Version: 2
# Device Node UUID Status
0 disk1s3 9D955C85-7EC0-4E92-848A-62D9F7C12EED 0% (Rebuilding)
1 disk0s3 2BFB55BB-EFF9-438C-A1F9-A8ED7A93D385 Online
===============================================================================
Hope this helps,
Cheers,
Arthur

Raid with disk utility

Hi there
I have an odd setup, however let me explain the whole situation.
I recently bought 2 external firewire drives with the idea of setting up a raid mirror so i could backup all my data safely.
However, it appears I cannot plug both drives into my mac at the same time using firewire, or they drop off the mac. I have read some other forums and found that you need to plug each drive on a different firewire card. As my G4 has only the one set of ports this is not possible without buying an additional pci card.
However they support usb as well. I can plug one drive in as firewire and the other via the usb at the same time fine, but now cant get the disk utility to raid the drives.
Is there a way to do this or to "trick" osx into thinking they are both firewire drives? Any hack or workaround welcome - even if it requires editing odd files via the terminal as this is a test system anyway and can reinstall if i need to.
Pete

Hi Pete;
RAID 1 or mirroring is NOT a good backup solution.
The primary purpose for RAID 1 is to protect from disk failure.
By way of an example as to why RAID is not a backup solution, consider what would happen if you had an application which had a dozen files opened. The application aborted taking all of the file with it.
How could recover with RAID 1? You could not because as soon as the application aborted all of the files would be removed from all of the disk in the RAID array. You would have no way to recover without a backup of the data. Hence data on RAID 1 must be backed up.
If you still want to create this RAID 1 array, I would certainly recommend that you don't mix USB and Firewire. Any RAID is dependent on the various parts of the array being similar as to connectivity and hardware.
Allan

Xserve RAID won't RAID in disk utility

I have a XServe RAID that won't RAID in disk utility. The XServe is fully populated and there are two arrays created. Both of those arrays show up in disk utility and will only be partitioned with an Apple Partition Map. If I try to partition them GUID, that partition fails (system formatter failed). Once, I partition them APM, two volumes show up on the desktop. Then, I try to create a software RAID with those two volumes and I can not get the volumes to RAID together. The error message in disk utility says (RAID can not be modified). I have checked the system log and it says something about a socket error or that it can not bind. Does anyone have any ideas on why I can not create this RAID?
My end goal is to have 2 hardware RAID 5's and put a striped RAID set on top of that to have one large volume for Final Cut video editing.
I'm using a Mac Pro with Atto Celerity 42ES fibre card.
Thanks

This may be a little too late, but maybe it will help. I'm not sure why this happens. I reinstalled my server, and I could not access the drives, even though they showed up in disk utility (as a blank file).
Here is what I did to fix it:
1. Open up Disk Utility
2. Make a disk image of the drive you want to mount, save this somewhere accessible (i saved it on another one of my RAID drives)
3. Erase the disk, it should then mount and be accessible
4. Restore the image onto the drive.
Cheers!

Maximum drive size for mirrored RAID

I'm want to set up a mirrored RAID with two 4TB drives that I have. When I put the drives in the tower (Mac Pro, OS 10.8.5) and open Disk Utility, the RAID button at the top does not show up for these drives. I only see First Aid, Erase, and Restore. Is there a max size for a drive that I'm exceeding? Or is it something else?

Hi - from the research I have done, there is a BUG in the OS. A solution is to boot with an older version of OS X and format the drive with the version of disk utlity on the older OS, or yank out the drive and put it in one of those 'drive toaster' type devices and format it EXTERNALLY. The problem seems to be localized when it's formatted with the drive INSIDE the MacPro.
You would figure that this would be a high priority fix, but NO. I went nuts for a few days trying to figure out WHY I could not see the RAID tab.
There is also third party software that has a more robust RAID solution. I have NOT tried it yet, but you should check it out.
http://www.softraid.com/
Alfred
PS: If you've resolved this problem, do share your findings here too!

Program with Mac Mirrored Raid

Hi guys;
I'm new to the Raid thing so please be patient.
I can make a mirrored raid no problem.
I had a disk go bad and needed to replace it.
I can't seem to figure this out without destroying the raid itself.
I read online about a demote button and cant see one anywhere on Disk Utility's Raid section.
Any help would be great. I find the online sites that I have found to be vague at best, and they always mention
things that I can't seem to find on the GUI interface.
Andrew

So I did more digging and found this
http://cryptosmith.com/node/309
I'm not going to go into how much of a letdown this is.
I decided to experiment with two older drives before I chance losing everything.
So I dragged a 1 gig file on to a Raid.
Took out one drive of the Raid, replaced another drive.
Followed the directions on the link above and its working.
But its telling me it'll take 1 day, and 10 hours to rebuild.
I can't count the number of times I could drag and drop the file in that time.
I forsee the drives burning out before the rebuild is done.
Again, I'm not going to mention what a letdown this is.
Somewbody must have a better RAID or solution somewhere.

Mirrorred RAID Rebuild Failing

Hello,
I had a mirrored raid setup on 10.6.7, everything was working great for the last month, then today I went into disk utility and it said one drive failed. After checking the drive, there didn't seem to be any problem with its operation, so I can only assume it was a software/communication failure.
Clicking the rebuild button resulted in this error:
Rebuilding RAID set failed with the error:
POSIX reports: The operation couldn't be completed. Operation not permitted.
So I tried removing a disk, that also failed with the same error.
I then erased the failed drive which automatically removes it from the RAID configuration. Now when I try to add it back to the configuration I get the exact same error.
Has any experienced this issue and have any suggestions on how to get RAID back online?
Thanks in advance!
Michael

Thanks for your reply.
Yes, I am sure that the drives are working. I do not know what caused one of the drives to 'fail' as far as disk utility was concerned - but it was online when I checked it again.
I had issues while originally creating the RAID configuration, similar POSIX issues.
I have managed to get the configuration back online using the SoftRAID, but I am unable to create any new RAID configurations or modify existing ones using Disk Utility. Is it possible its an issue with POSIX and the drive USB drivers? Though I have tried with 3 or 4 different brand drives.
SoftRAID allows the drive set to be converted to a Disk Utility set after creating/repairing it - so thats what I have done for now.
I will try to setup/repair this all again once I have Lion installed and see if they fixed it in that version.
Any suggestions on how to get Disk Utility's RAID configuration on a Intel Core 2 Duo Mac Mini would be appreciated. I have filed a bug report with Apple as well. SoftRAID was a suggested alternative to a few other posts on the discussions for similar issues.
Michael

Disk Utility & Mirrored RAID

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