Advice on external MIRROR RAID

Looking to get an external MIRROR RAID for my Mac.
What would you guy recomend?
The 1TB MyBook Pro by Western Digitial looks good,
What are people using? anyone using Lacie?
R

just a thought, there may or may not be issues with this idea.
how about using a vault for one of the backups, or just backing up the Aperture library file, containing all of your managed images. onto one of the external HDD's.
next, simply make a copy of the currect Aperture library with a new name, open that new copy library in Aperture, then move the entire library to being referenced on the other external drive.
or better yet, if you can take the space hit of having this on both external drives, having the full aperture library file on each, as well as the referenced library. and have double backups on each RAID setup.
with these two type of backups, you will be able to restore the entire library, if that is a good solution at the time, or if you are in a hurry for a specific project, you can simply find that project in the referenced files.
I don't think that would be a super difficult process to have a really efficient backup system, it will take awhile, double the time of a single backup, but will give you all the options you may want.
honestly, if it were me, I would just backup the Aperture library file periodically to each Raid volume, as Library files can still be opened up right in finder, using the Show Contents comand, and maybe even Vaults can as well? I wouldn't be suprised if they could. need to do a little more research on that, if a vault file can be opened just like a library file, then you really shouldn't have to worry about restoring the whole vault if you were in a hurry and just find the photos you need at the time. and eventually do a full restore.

Similar Messages

How to separate drives in a mirrored RAID without losing contents?

Perhaps senseless questions (non-issues), I'm not sure. Better to ask than to regret a stupid move ...
I have an external mirrored RAID array (running 10.4.11) which is generally my startup volume(s) for a G4 Mini. Obviously, I can also boot from the internal drive.
1. What happens if I disconnect them from each other (firewire cable) ? Is the drive that remains connected to the CPU still accessible?
2. If I (somehow?) "Undo" the mirrored RAID set, is data on either or both drives lost or do the contents remain intact and accessible?
3. If drive contents remain intact and accessible, then how does one "undo" a RAID set" ? Disk Utility "Help" and several forum searches have not been helpful (void of all pertinent content).
My apologies if these are "stupid" questions and thanks in advance for informed responses.

thanks - nice to know
However - when I open DU, select this raid set, choose the RAID tab, I see NO option of "delete" - only "erase" button. Perhaps I need to (re)start from a different drive.
IMO neither one of those terms is exactly intuitive for uncoupling a mirrored set. I do not want to delete or erase anything, just uncouple them so they are once again independent drives (without loss of content). BTW, since I typically boot (start) from the current set, I presume that either drive (once decoupled) will also be boot-able with preferences etc. persevered!

Creating a mirrored raid set with a hard drive that already has data on it.

I have a hard drive that I keep my photos on, and want to create a mirrored raid set that includes this drive, with its data, and another drive. How can I do this without erasing the drive with my photos on them? I am running 10.7.5 if that matters.
Thanks for any help.

Creating a Mirrored RAID reformats the drive and loads a substantial RAID driver and some tables onto it. When completed, the drive is inherently a member of a RAID set, and will continue to be so even if moved to another Mac.
because of this, you cannot create a RAID directly on a standard drive that contains data already in any reasonable, risk-free way.
To amplify what The Hatter has said above, Mirrored RAID is not Backup. Mirrored RAID only increases mean time to repair to keep a drive failure from becoming a Data Disaster. You still need a Backup. Mirrored RAID does not protect you from deletions from user error, crazy software, or "just because".
I run a mirrored RAID in my Home Server, which contains all the Users files for everyone in the Household. And I also recognize (after being burned by it) that Mirrored RAID is helpful, but not a sufficient Backup by itself. I back up the Users Drive automatically to an External drive using Time Machine. [So what I am advising is not just theoretical, I am living what I am advising.]
With WD Black 1TB and other very good drives in the under US$100 range, there is really no reason NOT to invest in several drives for such an undertaking.

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!

Mirrored Raid as boot disk?

I have a flat panel iMac (PPC) that I would like to have a bit more reliable. Due to the number of files I have on this machine, it is currently configured to boot from an external Firewire drive. Recently, I have added a second external firewire drive of the same size, and am considering a Mirrored raid configuration for this system. I am primarily interested in reliability, not increasing the performance of the system, hence the mirrored, rather than stripped, raid configuration.
It is clear from other postings on the web that a stripped raid requires a) reformatting the drives, losing all data, and b) cannot be used as a boot drive, which is mandatory in this case.
Therefore my questions:
1) Can I create a mirrored RAID using Disk Utility without data loss? One drive is newly formatted, the other is full of data.
2) Can this RAID be used to boot an early flat panel iMac?

Hi Eric Hildum;
1) No.
2) Probably yes. Practically no because it is going to cause you more problems then it is worth running both disk ins a RAID over a single Firewire channel.
Don't forget that Raid is not a valid backup solution. Any data on the RAID array should also be backed up for it's protection.
Personally for the home user, I think a good backup solution beats RAID. Usually there are less problems with backup then RAID.
Allan

Fan Speeds, and Mirror Raid with New Internal Hard Drive

Regards,
I recently installed and formatted a new hard drive in my PowerMac dual 2.3 ghz computer and I have a few questions.
1. Now that there are two hard drives do I need to do anything to ensure that the fan on my computer can keep them cool? I think the fans I have in the hard drive bay is enough, but I do not know if they will automatically set themselves to run properly. I can monitor the fan speeds and temp from iStat pro, but do not remember what level the temperature was before installing the new one.
2. Given that my new drive is a SeaDisc hard drive and the older one is a Western Digital, will this cause any problems in creating a mirrored RAID. I believe that both are 7200rpm drives, and my second hard drive is a little larger (I will just have unused space after making the RAID). I am concerned with the fact that these two drives are from two different manufactures. Will this cause problems or drastically slow down the reading and writing of data? Has anyone else experienced problems in making a mirrored RAID from two hard drives that are not exact matches, and even come from different manufacturers?
Any advice will help.
Thanks
earpshmael

Hi earpshmael;
Generally when creating RAID arrays the more similar the drive the less problems you tend to have.
The real question is exactly why do you want or need RAID?
I think so many people seem to think that RAID will solve all of their problem. I hate to tell you the bad news but it will not.
Generally there are to varieties of RAID available using the software RAID built into OS X which are 0 and 1. RAID 0 or stripling is generally for moving large file rapidly for applications like HD video. It usually doesn't help the OS. RAID 1 or mirroring is for protection from drive failure. It is not a valid backup solution.
Allan

Mirrored RAID set deletion

Hi all,
I've set up two USB disks as a mirrored RAID set connected to my MacBook.
Now, I want to remove this RAID set (since it doesn't work so well for me).
In the manuals, Disk Utility is said to split nicely a mirrored RAID set, resulting in two disks with the same contents, when removing a mirrored RAID set.
However, when I try to do it, Disk Utility warns me that all data on the disks will be lost (which should not be the case...).
I can't afford to loose all data (120GB of photos), and I can't easily make a backup (120GB of data is tough to backup !)
Who should I trust ? Disk Utility or the manual for Disk Utility ?
Will my data be lost or not when I delete this mirrored RAID set ?
I need an authoritative answer... Could someone help me ?
Thanks,
Chris

Thanks for your advice... but if no RAID disk is plugged in, the RAID does NOT show in Disk Utility.
As I understand it, the partition scheme is different when using RAID... So a disk that is part of a RAID set has to be modified to get out of the mirror...
But it seems Disk Utility cannot disconnect a single disk from the RAID.
My RAID is now out of sync, and I won't attempt to resync it again...
So I would like to remove the whole RAID thing, and just get two disks, one that will be reformated, and one where all the data should be kept...
Later this week, I'll have access to another (afaik Firewire) disk... So I'll make a backup and simply try to delete the RAID... If it goes wild, I'll have that backup to recover.
I'll keep you posted if I can.
However, things should be made clear somewhere : either in the docs or in Disk Utility... I submitted some comments about the documentation on apple's website.
Bye
Chris

Mirrored raid and bootcamp.

On my mac i have a mirrored raid of 2 external hdds for music and photos etc.
I intend on buying a new mac soon, now I know I can just unplug and plug them into the new one no problem.
My question is though, that with my new mac i will be using bootcamp, and I am unsure what will happen if I boot into windows with my mirrored raid setup still plugged in.
Jonny

I'm going to try to install XP using an extra drive I have lying around and the Pro Caddy:
http://www.transintl.com/store/category.cfm?Category=2704
These keeps the 4 main drive bays free for OSX.

Splitting Mirrored Raid Drives

Hello,
I have two external drives that are striped with one mirroring the other. I want to split or separate them without losing data. Can I just continue using the primary drive that comes up on the desktop (without plugging in the mirrored drive) without any problem? If I separate the mirrored drive, I presume I will need to erase it, and will not be able to access the media on it, correct? Is there any way to access the media on it and use it without erasing media?
I tried to access just the mirrored drive to see if it showed up in Disk Utility, which it did not. Then, after plugging in both drives, Disk Utility is now repairing raid slices...for another 8 hours. Did I damage my media?
If one can never access the data on a mirrored drive, then what is the benefit of it being a "backup"??
Thank you in advance,
Video Editor

Is the RAID striped or mirrored. You said they were "striped" with one "mirroring" the other, but this is incorrect terminology. Either the RAID is striped or mirrored. You can create a mirrored RAID from two identical striped RAIDs, but an individual array is either striped or mirrored.
If you truly had a mirrored RAID, then separating the drives would not affect the data as each drive simply has a copy of the other. However, if you truly had a striped array that you separated, then your data may be lost completely because each drive actually has one half of the data and the other drive has the other half. Each file is literally split between each drive. Lose a drive and you lose the data.

Mirrored RAID set has degraded following power outage.

Hello,
Following a recent power outage our Mac Pro running Leopard OSX Server with 2 x 1TB discs in a Mirroring RAID configuration (with an installed RAID card) developed a 'severe error' message.
The Raid Set R0-1 has a Viable (degraded) status.
Drive One (or bay 1) is 'Good' and 'Assigned'
Drive Two is 'Good' but with the State - 'Roaming'
Also, the events display describes the failure of a drive 3 (there isn't one) and that the R0-1 is Degraded and no spare is available.
So, we're a little confused.
1. Is the Drive 2 no longer part of the RAID mirror (i.e. Roaming)
OR
2. Something more significant has happened hence the bogus Drive 3 message?
Any suggestions or advice would be much appreciated as always.
Thanks
Steve

Yes. Verification with the GUI tool is the first step. But... hmm, if you are dropping communications with the card, that is not a good sign. Make sure you have a backup and then try a PMU reset on the system. Maybe there is something wacky in the power manager. Then try any/all of these from Terminal to get more information:
raidutil list status
raidutil list eventinfo
raidutil list raidsetinfo
This should provide feedback. If these commands fail, then I fear that the card is not responding. Do you have AppleCare? It might be time to call for a replacement card.
Hope this helps

Xserve - Mirrored RAID Failed? Degraded? Confused...

Hi,
Can anyone shed some light on this situation please? Disk utility tells me one thing and Server Monitor tells me another.
I have an X-Serve with 3 drives and a Mirrored RAID Set running 10.5.8.
Server Monitor is showing a yellow status for disk 1 and disk 2. Raid Status: Degraded (Mirror) Pre-failure Warning: No Warnings
Disk Utility on the other hand shows that the Mirrored RAID sets are Degraded because disk2s4 = Failed and disk2s2 = Failed.
Running disk utility commands in terminal also show disk2s4 and disk2s2 as Failed.
I have not yet tried to Rebuild or eject / reconnect the disk. The only thing I've really done is some research and rebooted the server.
It sounds like disk 2 has failed. Is there any way to confirm it's dead? Are there any serious risks of trying to rebuild?
Thanks.
- F4st

I'm not sure why you think you're seeing conflicting information…
Server Monitor is showing a yellow status for disk 1 and disk 2. Raid Status: Degraded (Mirror) Pre-failure Warning: No Warnings
OK, So Server Monitor says the RAID is in a degraded state…
Disk Utility […] shows that the Mirrored RAID sets are Degraded because disk2s4 = Failed and disk2s2 = Failed
Running disk utility commands in terminal also show disk2s4 and disk2s2 as Failed
I don't see this is anything different. All three methods are telling you disk2 has failed and your mirror is relying on disk1 for all activity.
Is there any way to confirm it's dead?
Umm.. you mean other than Server Monitor, Disk Utility.app and diskutil?
Face it, it's dead. It's had it.
Are there any serious risks of trying to rebuild?
Sure. If the disk is dead, it's entirely possible that rebuilding the array on that disk will fail. You run the risk of a problem on disk1 and then all your data is gone.
My advice: Replace disk2 as soon as possible. If not sooner.

Testing a Mirrored RAID

I created a mirrored RAID out of 2 500GB LaCie FW drives. It appears to have been successful and I loaded about 100GB of info onto it. They are connected to a G4 dual 1.25 running 10.4.x.
How can I test it out to be sure that the 2 drives are, indeed, mirroring themselves? Can I somehow inspect the contents of each of the individual drives, apart from the RAID?
I'd had to count on the redundancy and then find out that it was not working correctly.
Typomarx
G5 dual 2.0 Mac OS X (10.3.9)

I not mirroring my local drive.
I have an external FW drive that I put my jobs/important files on. This IS my back-up.
I work on them on my local drive and then copy them to the FW drive when I've finished.
I'm mirroring THAT drive so that my jobs are all backed up on a redundant drive.
As needed, I recall jobs from that Jobs "server", work on them locally and then recopy them back to the "server." Truly a poor man's server.
If I'm working on a job on my local drive and my Mac craps out and takes the file with it -- it should not affect my jobs and back-ups at all.
Or so I'm hoping.
Then if one of the RAID disks craps out, I haven't lost everything. I have the other one which contains a complete record.
I can than fix/replace the faulty disk and be on my merry way.
Does this sound reasonable?
Typomarx

Little software mirror raid configuration question

Setting up a Boot volume mirror RAID of two internal drives with Disk Utility -- any suggestions as to whether to check "RAID Mirror AutoRebuild" or not?
I understand the concept, but in practice am wondering, if I leave it unchecked, will I be notified if one of the drives fails? Don't really want to be having to manually check periodically if both are still running okay...
Thanks!

Thanks so much for thoughts and that great software pointer. I bought two of the same make/model drives with this mirror in mind so I should be cool there.
Yeah, I know your backup advice is very sound -- and I'm absolutely still chewing on whether I want to put my eggs in Mirror RAID or Super Duper. I understand the pro/cons of each, but I also just know that I'm not going to do both -- I'm just not that high maintenance/big spender.
I was edging towards mirror just because, in 3 years of doing regular clone backups I've never happened to have the need to restore yesterday's system due to a bum software update or the like, but I have had drives fail on me and lose the last two days of intensive work... I like that with Mirror there's no thought.

MacMini Mirror RAID degradated, 2nd slice failed

I have a Mac Mini Server Late 2012, with the following specs:
- 2.3 GHZ I7
- 10 GB RAM (1x2 GB, 1x8 GB)
- Dual 1 TB HD 5.400 RPM
- OSX Maverick 10.9.5
- Mirror RAID
Apparently an error with OwnCloud caused the disk to get almost full. I found the problem, deleted the files and then ran disk utility and, for my surprise, I found the raid hd (serverhd) marked as "degradated" and the 2nd disk marked as "failed":
Running diskutil on terminal confirms that the 2nd slice as "failed":
My questions are:
1. Does the failed status on disk1s2 means that the disk PHYSICALLY failed or that the data in the disk doesn't match with the one in the 1st disk?
2. If this is a data failure, how can I rebuild the data in the 2nd disk? By selecting the failed disk in disk utility and hitting Rebuild?
TIA
Victor Espina

I finally solved this issue:
1. Made a full copy of server's HD in a external disk using CCC
2. Changed boot drive to use the external disk. In theory, this was not needed but I prefered to boot from a different disk just in case.
3. Once booted from the external disk, when to Disk Utility and "demote" the failed disk from the RAID array.
4. Using Disk Utility, I reformated the failed disk and added again to the RAID set (to do this, select first the RAID set and then drag & drop the disk from the left panel)
5. Once the disk was added to the RAID set, I pressed Rebuild and waited until de RAID set was rebuilt.
6. Then I set the HD as the boot drive and restarted the server
Thanks all for your help on this.
Victor Espina

Rebuilding a Mirrored Raid using Disk Utility

I have a mirrored raid set up via disk utility. For some reason one drive was switched off recently so the 2 drives are now out of sync. Disk utility now says the raid is 'Degraded' with one of the slices marked as 'failed'
I can ignore this as the drive appears fine on the desktop. But I need it to be working correctly as a fully operating RAID.
If I click 'rebuild' it gives a warning saying 'Rebuilding a RAID set will destroy all information on the replacement disk “RAID Slice”.
SO- I'm assuming rebuild will correct the error and make it work but I'm concerned about this warning about destroying data! I assume it will simply copy everything from Drive A to the 'degraded' Drive B??
Thanks for any suggestions.

"SO- I'm assuming rebuild will correct the error and make it work but I'm concerned about this warning about destroying data! I assume it will simply copy everything from Drive A to the 'degraded' Drive B??"
This should indeed be the way it goes but since i do not have enough experience with that kind or RAID setup i strongly suggest backing up / cloning drive A to an external before doing the rebuild... just in case.

Advice on external MIRROR RAID

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