DonCelian
Level 1 (0 points)

Q: RAID 1 (LaCie) - Possible to Partition??

Greetings Everyone!

 

I'm a very excited and happy new iMac owner (Mid 2011, 3.4Ghtz, i7, 8GB)...

 

I recently purchased a LaCie 4TB (RAID1, 2TBx2TB) 2Big Thunderbolt Drive for the following 2 purposes:

 

1) Create and Store a "Bootable Backup" of my  iMac hard drive.

 

2) Fast External Storage for all my family's media (RAW photos, Music, Movies..)

 

However, after much research (as well as some conflicting reports), I'm really confused as to the possibility AND advisability of creating a partition in my RAID1 setup.  I initially chose this Thunderbolt drive because of the "safety" of creating a mirrored RAID setup... however, according to the SuperDuper! user manual, it is STRONGLY recommended that any backup be partitioned or on a separate disk altogether from regular storage (i.e. Media).

Now, each time I go to attempt to partition my RAID set using DiskUtility it states in the partition info that "this partition can't be modified.  Changing a RAID partition may leave the RAID set unusable."   This statement frightens me and keeps me from proceeding past this point..

My LaCie 2Big does not support JBOD.  So, is it in fact possible to partition my RAID1 setup or am I stuck with no "bootable backup" on the external drive, in which case I'd be forced to save a bootable backup to DVD's (optical) or find some other alternative??

 

I should mention that I do have a Time Capsule running regular Time Machine backups, which from my understanding are not "bootable backups" or a clone...

 

Any assistance is VERY MUCH APPRECIATED, as I'm very eager to implement a decent backup system (including a "bootable backup") as soon as possible.

The LaCie is just sitting there empty in RAID1 right now until I can figure this out and proceed..

 

Thank you in advance for any help and guidance..

iMac, Time Capsule (Time Machine), LaCie

Posted on Aug 1, 2012 10:07 AM

by Camelot,Solvedanswer
Camelot Camelot
Level 8 (47,366 points)
Mac OS X
A:

I think you're reading too much

Or, at least, reading too much into different people's documentation.


SuperDuper is a general-purpose data duplication application and any advice it gives can only be generalized. In this case what they're telling you is that you shouldn't back up your data to the same physical disk - and that just makes sense because if the physical disk breaks you lose both your data and the backup.

 

But that's not your situation here.

For one you're not creating a backup of your data on the same disk - you're creating a backup of your main system disk, plus a second storage location for media. So right there you can ignore SD's statement since it doesn't apply to you - or, more correctly, you are already complying with their suggestion.

Secondly, SD doesn't know that what you're backing up to is a RAID volume, which has its own set of data protections built-in. Like I said, it's advice will only be general.

 

So, in this case you should be absolutely fine to take that 2TB disk presented by LaCie and partition it in any way you want. The fact is that the LaCie has handling all the RAID 1 work, so even the OS isn't aware that the disk is mirrored, and that might be where the confusion sets in.

 

In Disk Utility you should see two disks - your internal OS disk, and the 2TB LaCie (which is, in reality, two 2TB drives in a mirror config, but the OS doesn't know that).

Go ahead and select the LaCie disk (not the existing partition(s)), then click the Partition tab.

Set the number and size of partitions you want and you're done.

 

Each of the LaCie paritions will be reasonably protected by the RAID 1 setup in the LaCie enclosure.

Posted on Aug 1, 2012 12:34 PM

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DonCelian

Q: RAID 1 (LaCie) - Possible to Partition??

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  • by gcortes,

    gcortes gcortes Dec 18, 2012 10:39 PM in response to Christopher Murphy
    Level 1 (5 points)
    Dec 18, 2012 10:39 PM in response to Christopher Murphy

    LaCie confirmed that it's not possible:

     

    The Apple Disk Utility does not allow a software RAIDed volume to be split into multiple partitions. This is not a limitation of the 2big itself, it is a limitation imposed by Mac OS X and the Disk Utility application.

     

    I had planned on creating a separate partition for a back up image of the main SSD like the OP.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Dec 19, 2012 12:07 AM in response to gcortes
    Level 3 (555 points)
    Dec 19, 2012 12:07 AM in response to gcortes

    I'm a little unclear on the advantage of partitioning for this use case. If you want a separate file system for Time Machine, while that's a good idea, it can be done by creating a sparse bundle disk image, which grows as needed.

  • by Chacapamac,

    Chacapamac Chacapamac Dec 19, 2012 5:47 AM in response to Christopher Murphy
    Level 1 (0 points)
    Dec 19, 2012 5:47 AM in response to Christopher Murphy

    I’m a little confuse, can we or not partition a level 1 raid?

     

    What about —>

    https://discussions.apple.com/message/9945127#9945127%239945127

     

     

    Normally you mirror entire drives and just drag into the window. If, instead, you want to have multiple mirror volumes, or mirror and standard:

     

    Create two partitions on each drive that are identical (the drives really should also be same make/model/firmware)

     

    Drag "A1" and "B1" into the RAID setup window.

    Then you still have A2 and B2 that you can leave, or combine into RAID set.

     

    Apple does have tech note on how. The whole thing is much easier and can be changed easier if you were to buy SoftRAID.com product. It also offers "stripe reading" for mirrors to improve performance.

     

    Most people use two drives but having three drive mirror has added redundancy in case of failure, and you can break one drive off for backup storage and still have two drives.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Dec 19, 2012 11:02 AM in response to Chacapamac
    Level 3 (555 points)
    Dec 19, 2012 11:02 AM in response to Chacapamac

    I haven't been able to figure out a way to do it through Disk Utility. It looks possible to do it from the command line.

  • by gcortes,

    gcortes gcortes Dec 19, 2012 11:02 AM in response to Chacapamac
    Level 1 (5 points)
    Dec 19, 2012 11:02 AM in response to Chacapamac

    I tried that method and it worked. I'm going to pass it by LaCie to see if they have any issues with it.

     

    Screen Shot 2012-12-19 at 10.55.20 AM.png

    I only have one physical 2Big.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Dec 19, 2012 11:04 AM in response to gcortes
    Level 3 (555 points)
    Dec 19, 2012 11:04 AM in response to gcortes

    That is extremely non-obvious. The RAID GUI in Disk Utility is honestly one of the worst UI/UX's I've experienced from Apple.

  • by gcortes,

    gcortes gcortes Dec 19, 2012 12:52 PM in response to gcortes
    Level 1 (5 points)
    Dec 19, 2012 12:52 PM in response to gcortes

    Well, LaCie poured cold water all over the method:

     

    This method will reduce overall performance of the unit. It also results in a configuration that means that if a single drive mechanism fails, you would likely loose all information on both drives; essentially defeating the purpose of having RAID1 in the first place.

     

    As a result, we do not recommend or support using the unit in this configuration.

     

     

    I don't why it should cause the problems described, but I'll take their word for it.

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Dec 19, 2012 2:02 PM in response to gcortes
    Level 3 (555 points)
    Dec 19, 2012 2:02 PM in response to gcortes

    In any case I would test it. If Apple is allowing you to produce a configuration of two RAID 1 partitions, something which is allowed on Linux and survives just fine (I have tested that a lot), then it's a huge bug. Either it's a bug in the GUI for allowing it; or a bug in the underlying implementation. So I'm skeptical, I think it just means they don't want to support it.

     

    Unfortunately as I think about it, Apple's boot loader doesn't know what Core Storage is, and they also don't put the boot loader on the EFI System Partition either. So in either case, you wouldn't be able to boot from a logical volume. That's a drag as it's been possible to do this on Linux also for something like 6 years.

     

    But I'm not understanding your use case for wanting to boot from a Firewire drive anyway. For an emergency, OK, but I think you can do this from even a 2GB flash drive made with Recovery Disk Assistant.

  • by Chacapamac,

    Chacapamac Chacapamac Dec 20, 2012 3:52 AM in response to DonCelian
    Level 1 (0 points)
    Dec 20, 2012 3:52 AM in response to DonCelian

    What about SoftRaid (They tell me that their software will do it easy) and just bypass Disk Utility?

     

    I think that this type of backup is absolutely basic and a minimum in security. If Apple don’t have the ability to do it, it show sadly that their software is not ready for business use....

     

    Really sad for a company that pretend to be Innovative.... 

  • by Christopher Murphy,

    Christopher Murphy Christopher Murphy Dec 20, 2012 10:08 AM in response to Chacapamac
    Level 3 (555 points)
    Dec 20, 2012 10:08 AM in response to Chacapamac

    A Time Machine backup to RAID 1 is not basic. It arguably gains you very little in security. Instead of one Time Machine backup to RAID 1, your'e vastly better off with two Time Machine backups to two drives. For a business that is basic. Time Machine backups get corrupted, and once corrupt, both "copies" in a RAID 1 array are corrupt.

     

    And besides, this is innnovation in the consumer device world right now. Apple hasn't been in the enterprise or storage business for years.

     

    What you could do is partition the two drives the same, and mirror just one partition on each drive. The unmirrored partitions on each drive, you can use for alternating Time Machine backups. Or you can use one of them for Time Machine backups, and the other one for a bootable Carbon Copy Cloner type of backup. Two different kinds of backups on two disks, one of which is bootable.

  • by gcortes,

    gcortes gcortes Dec 20, 2012 12:36 PM in response to Christopher Murphy
    Level 1 (5 points)
    Dec 20, 2012 12:36 PM in response to Christopher Murphy

    I copied files to both partitions without problems. I then copied a 95GB directory and I didn't have any problems with it either. I suspect it probably will work fine and LaCie is just being cautious.

     

    I decided to go back to the single partition because the use case for having a bootable backup partition were it possible doesn't buy me much. The goal was to be able to be back up running should the SSD (OS and apps) fail. As I understand it, SSD failures are usually catastrophic so I would have to take the Mac Mini in for repair. I wouldn't have a computer to boot. Since I will have all my data on the RAID, my plan is to connect to my Macbook Air if the Mac Mini fails. My applications are already duplicated across both platforms.

     

    I also have a separate drive for my Time Machine backups in a fire and water proof enclosure (IOSafe) so my cofiguration is a bit overkill for a personal system. I spent years working with systems with RAED's (Redundant Array of Expensive Drives) and have lost a number of RAID drives on my Windows machines in the past so I error on the side of caution.

  • by Chacapamac,

    Chacapamac Chacapamac Dec 21, 2012 5:32 AM in response to Christopher Murphy
    Level 1 (0 points)
    Dec 21, 2012 5:32 AM in response to Christopher Murphy

    I revise my partition scheme on what you tell me. It make sens to have two separate Time Machine

     

    LaCie-Partition-scheme.gif

    Now, my question is if it work and did you do it with the Lacie Drive?

  • by Chacapamac,

    Chacapamac Chacapamac Jan 5, 2013 7:19 AM in response to Chacapamac
    Level 1 (0 points)
    Jan 5, 2013 7:19 AM in response to Chacapamac

    Ok I don’t think my new Sheme will work...

     

    I guess all partition have to be mirror, they probably cannot be some mirror and some don’t...

     

    In this case I will move one time machine backup with the first partition (Boot OSX, Windows, Stuff, Time machine 1 and leave a single Time machine patition alone that will mbe mirror...

     

    Now The REAL question : Is this working or not and if the use of software like “Softraid” can work?

  • by Rob de Jonge,

    Rob de Jonge Rob de Jonge Apr 30, 2013 7:18 AM in response to gcortes
    Level 3 (515 points)
    Mac OS X
    Apr 30, 2013 7:18 AM in response to gcortes

    I just created a similar setup, but did it with Western Digital Thunderbolt Duo 4GB.

     

    I created 2 RAID sets. They both work fine.

    But performance wise, the bigger one performs at twice the speed.

    Same RAID type. Same filesystem.

     

    I have no idea why!

  • by Alksion,

    Alksion Alksion Dec 5, 2013 9:44 PM in response to Chacapamac
    Level 1 (0 points)
    Dec 5, 2013 9:44 PM in response to Chacapamac

    Does anyone have confirmation of a partitioned RAID1 LaCie 2Big working?

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