Problems stting up RAID (Mirror) for boot drive.

Question

Problems stting up RAID (Mirror) for boot drive.

I have a Mac that I want to setup mirroring on the boot drive (it's running Mac OS X Server and once I get everything going I need to minimize downtime).

Since you can't move a drive with data into a raid set I first cloned the boot drive to a 3rd drive, booted off that drive, then set the two 80gb drives up as a mirror. after cloning the data from drive #3 back to the now mirrored pair I can't boot off the mirror.

I've tried using both the Startup Disk preferences and also the bless command to mark the raid as the device I want to boot from but it doesn't recognize it as a bootable device.

What do I need to do to make the raid bootable?

thanks,
Bill

MacBook Pro, 2.0ghz, 2gb ram, Mac OS X (10.4.6)

Posted on May 18, 2007 10:52 AM

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Answer 1

Kappy

Level 10

362,007 points

May 18, 2007 11:14 AM in response to Community User

If this be an Intel Mac then:

1. Both drives must be partitioned using the GUID partition scheme.
2. Both drives should be erased prior to including in the RAID.
3. The system should be an Intel version of OS X.

The system you plan to clone should be a known no-problem installation. Do the following to be sure:

Repairing the Hard Drive and Permissions

Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Installer menu (Utilities menu for Tiger.) After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer. Now shutdown the computer for a couple of minutes and then restart normally.

If DU reports errors it cannot fix, then you will need Disk Warrior (4.0 for Tiger) and/or TechTool Pro (4.5.2 for Tiger) to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.

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Answer 2

Dec 1, 2016 3:55 PM in response to Kappy

I deleted the mirror, repartitioned the drives to make sure they were GUID. Built the mirror again. cloned the data back but it will won't recognize the mirror as bootable.

DU didn't find any problems.

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Answer 3

Kappy

Level 10

362,007 points

May 18, 2007 10:56 PM in response to Community User

First check that the permissions are correct: Owner=system with R/W privileges; Group=admin with R/W privileges; Others with Read-only privileges. Next open Startup Disk preference and see if the mirrored RAID is shown as an available boot system. If so then select it and click on the Restart button.

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Answer 4

Dec 1, 2016 3:55 PM in response to Kappy

The drive I want to boot off (the mirror) is "Macintosh HD"

The temporary drive it's running on now is "Macintosh HD 0"

Both drives show up in the startup items preference panel, I have "Macintosh HD" selected. When I hit restart it fails to recognize it as bootable and fails back to the other one.

I'm not sure which folder you want the permissions set on. Here's what it looks like right now.

<pre>
viking:~ user1$ ls -l /Volumes/
total 8
drwxrwxr-t 32 root admin 1190 May 19 01:16 Macintosh HD
lrwxr-xr-x 1 root admin 1 May 19 01:19 Macintosh HD 0 -> /
viking:~ user1$ ls -la /
total 18275
drwxrwxr-t 32 root admin 1190 May 19 01:19 .
drwxrwxr-t 32 root admin 1190 May 19 01:19 ..
-rw-rw-r-- 1 administ admin 12292 May 18 09:15 .DS_Store
d-wx-wx-wt 2 root admin 68 May 18 01:50 .Trashes
-rw------- 1 root wheel 131072 Apr 24 11:38 .hotfiles.btree
-rw------- 1 root admin 1024 Apr 6 22:31 .rnd
dr-xr-xr-x 2 root wheel 128 May 19 01:19 .vol
drwxrwxr-x 38 root admin 1292 May 8 01:33 Applications
-rw-r--r-- 1 root admin 3584 May 19 00:19 Desktop DB
-rw-r--r-- 1 root admin 2 Apr 6 23:15 Desktop DF
drwxrwxr-x 3 administ admin 102 Apr 6 23:08 Groups
drwxrwxr-t 48 root admin 1632 Apr 14 00:59 Library
drwxr-xr-x 1 root wheel 512 May 19 01:20 Network
drwxrwxr-x 5 administ admin 170 Apr 7 00:43 Shared Items
drwxr-xr-x 4 root wheel 136 May 8 08:59 System
drwxrwxr-t 11 root admin 374 Apr 7 02:22 Users
drwxrwxrwt 4 root admin 136 May 19 01:19 Volumes
drwxr-xr-x 4 root admin 136 Apr 6 22:32 automount
drwxr-xr-x 40 root wheel 1360 Apr 6 23:26 bin
drwxrwxr-t 2 root admin 68 Jul 1 2006 cores
dr-xr-xr-x 2 root wheel 512 May 19 01:19 dev
lrwxr-xr-x 1 root staff 11 May 18 01:07 etc -> private/etc
lrwxr-xr-x 1 root admin 9 May 19 01:19 mach -> /mach.sym
-r--r--r-- 1 root admin 615584 May 19 01:19 mach.sym
-rw-r--r-- 1 root wheel 8557728 Feb 22 21:58 mach_kernel
drwxrwxrwx 2 administ admin 68 Apr 18 15:04 mnt
drwxr-xr-x 3 root wheel 102 Jul 25 2006 opt
drwxr-xr-x 6 root wheel 204 May 19 01:19 private
drwxr-xr-x 63 root wheel 2142 May 8 01:33 sbin
lrwxr-xr-x 1 root staff 11 May 18 01:26 tmp -> private/tmp
drwxr-xr-x 10 root wheel 340 May 1 23:10 usr
lrwxr-xr-x 1 root staff 11 May 18 01:48 var -> private/var
viking:~ user1$ ls -la /Volumes/Macintosh\ HD
total 18272
drwxrwxr-t 32 root admin 1190 May 19 01:16 .
drwxrwxrwt 4 root admin 136 May 19 01:19 ..
-rw-rw-r-- 1 administ admin 12292 May 19 00:56 .DS_Store
d-wx-wx-wt 3 root admin 102 May 19 01:20 .Trashes
-rw------- 1 root wheel 131072 Apr 24 11:38 .hotfiles.btree
-rw------- 1 root admin 1024 Apr 6 22:31 .rnd
dr-xr-xr-x 2 root wheel 68 May 18 13:19 .vol
drwxr-xr-x 38 root admin 1292 May 19 00:32 Applications
-rw-r--r-- 1 root admin 3584 May 19 00:19 Desktop DB
-rw-r--r-- 1 root admin 2 Apr 6 23:15 Desktop DF
drwxrwxr-x 3 administ admin 102 Apr 6 23:08 Groups
drwxrwxr-t 48 root admin 1632 Apr 14 00:59 Library
drwxr-xr-x 2 root wheel 68 May 18 13:45 Network
drwxrwxr-x 5 administ admin 170 Apr 7 00:43 Shared Items
drwxr-xr-x 4 root wheel 136 May 8 08:59 System
drwxrwxr-t 11 root admin 374 Apr 7 02:22 Users
drwxrwxrwt 2 root admin 68 May 18 13:19 Volumes
drwxr-xr-x 4 root admin 136 Apr 6 22:32 automount
drwxr-xr-x 40 root wheel 1360 May 19 01:13 bin
drwxrwxr-t 2 root admin 68 Jul 1 2006 cores
drwxr-xr-x 2 root admin 68 May 19 01:16 dev
lrwxr-xr-x 1 root admin 11 May 19 01:16 etc -> private/etc
lrwxr-xr-x 1 root staff 9 May 18 13:45 mach -> /mach.sym
-r--r--r-- 1 root staff 615584 May 18 11:34 mach.sym
-rw-r--r-- 1 root wheel 8557728 Feb 22 21:58 mach_kernel
drwxrwxrwx 2 administ admin 68 Apr 18 15:04 mnt
drwxr-xr-x 3 root wheel 102 Jul 25 2006 opt
drwxr-xr-x 6 root wheel 204 May 18 11:34 private
drwxr-xr-x 63 root wheel 2142 May 19 01:13 sbin
lrwxr-xr-x 1 root admin 11 May 19 01:16 tmp -> private/tmp
drwxr-xr-x 10 administ staff 340 May 1 23:10 usr
lrwxr-xr-x 1 root admin 11 May 19 01:16 var -> private/var
</pre>

MacBook Pro 2.0ghz, 2gb ram / MacMini 1.83, 2gb ram Mac OS X (10.4.9) Compaq DL380 (Gentoo Linux). Tatung U10 (Sparc, Solaris)

MacBook Pro 2.0ghz, 2gb ram / MacMini 1.83, 2gb ram Mac OS X (10.4.9) Compaq DL380 (Gentoo Linux). Tatung U10 (Sparc, Solaris)

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Answer 5

Dec 1, 2016 3:55 PM in response to Community User

A bit more information.

I've read several places that you can't boot off USB devices but the extra drive that I'm running the system on now is an external USB so it seems they do work now.

The mirror set is the internal 80gb drive and an external usb 80gb drive.

When I broke the mirror each side was bootable but before I broke them apart (using DU) I couldn't boot off the mirror.

That seems to indicate both had good copies o the data and the drives were boot set as bootable (formatted with GUID set).

Not sure what to try next.

Maybe the USB drive in question is bootable solo but not as part of a mirror and I neeed to get a fw case?

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Answer 6

Kappy

Level 10

362,007 points

May 19, 2007 10:54 AM in response to Community User

You can boot an Intel Mac from a USB drive. I'm not sure what your problem stems from although it could be because one of the drives you are using is an external drive. I believe (not sure) that you would need to use two internal or two external drives in the RAID.

In your situation, however, I would not recommend using a RAID. A far better solution is to use your external drive as a simple backup drive. Use backup software to maintain your external clone with regular scheduled backups.

There is really no reason to use a RAID for your purposes. Mirrored RAIDs are used for data redundancy not backups and certainly not boot volumes. Furthermore, the RAID will be slower than your internal drive alone and slower than the slowest drive in the set - the external drive.

I have two MBPs and a MB. I have three external drives. Each drive starts with a clone of the current working system on each laptop. I use a backup program to run regular updates of the clone. Here are some backup programs I can recommend:

You can make a bootable clone using the Restore option of Disk Utility. You can also make and maintain clones with good backup software. My personal recommendations are (order is not significant):

1. Retrospect Desktop (Commercial - not yet universal binary)
2. Synchronize! Pro X (Commercial)
3. Synk (Backup, Standard, or Pro)
4. Deja Vu (Shareware)
5. PsynchX 2.1.1 and RsyncX 2.1 (Freeware)
6. Carbon Copy Cloner (Freeware - 3.0 is a Universal Binary)
7. SuperDuper! (Commercial)

Visit The XLab FAQs and read the FAQs on maintenance, optimization, virus protection, and backup and restore. Also read How to Back Up and Restore Your Files.

This would be my recommendation.

As for drive permissions they are set for the drive not the contents. You select the drive then press COMMAND-I to open the Get Info window. Set permissions if needed in the Ownership and Permissions section of the Get Info window.

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Answer 7

Dec 1, 2016 3:55 PM in response to Kappy

The mirrored root is for server uptime. Once I have everthing migrated off my Linux server to the Mac server I won't be able to afford the downtime from a single drive failure.

I have a local raid 5 nas device locally that I'll be making point in time backups to (haven't picked my software for that yet) as well as weekly offsite backups to a nas device about 90 miles away so I'm covered for that type of backup. Just need to get the system drive mirrored to avoid downtime.

Maybe I'll try the mirror across the 2 external drives as a test and see if the 2 external/2 internal vs one of each thought is my problem.

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Answer 8

Kappy

Level 10

362,007 points

May 19, 2007 11:38 AM in response to Community User

I would do this: Set up your main RAID separately from the boot volume. Use backup software to backup the main drive to the external RAID. This provides the data redundancy you require. I use a similar setup with my Mac Pro. I have a boot volume that is backed up to a mirrored RAID. This is typically what I've seen at some of the Unix sites I've worked at over the years. Striped RAIDs were used for main storage and mirrored RAIDs for backup and data redundancy. As far as I was aware none of them used a RAID for the startup volume.

But then I'm certainly no RAID expert, so don't take my advice as the definitive word on the matter.

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Answer 9

Dec 1, 2016 3:55 PM in response to Kappy

In that situation if you take a drive fault on the os drive your system goes down. since you have a good copy you can get it back online quickly but you still take the outage.

Mirroring the boot/root drive gets rid of the outage completely in the event of a single drive failure. Then you can schedule a replacement of the failed drive when its convenient to take the outage.

Really need both mirrored data and backed up data to protect the system.

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Answer 10

Kappy

Level 10

362,007 points

May 19, 2007 12:21 PM in response to Community User

Well, you know what you need. I've provided about all the help I can within the scope of my expertise on RAIDs.

There has been a plethora of coverage on RAIDs in the Mac Pro Forum. Perhaps some searching there will provide some additional help.

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Answer 11

Dec 1, 2016 3:55 PM in response to Kappy

Thanks for all the help.

I added that XLab site to my bookmarks, looks like lots of good stuff there. appreciate the link.

Conceptually I know what I need to cover my data requirements, been building/supporting servers for way too many years now. Trick is implementing it in Mac OS X. I've only built Linux and Solaris servers (ok, I dabble in Windows sometimes too) in the past so this is a good learning experience for me 🙂

Thanks again for all the time helping me get rolling in the right direction.

Bill

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