Jerryrigged
Level 1 (10 points)

Q: Promise Pegasus: migrated to larger array, Mac still sees smaller array.

On my R6 Pegasus, I migrated from a 4x1tb raid 5 (3tb capacity) to a 5x1tb raid 5 (4tb capacity) array. I did this with the Pegasus utility. I did not have to delete my old array, I just used Promise's utility to migrate the raid 5 array from 4 disks to 5 disks. When done i had the Promise utility expand the logical volume from 3tb to 4 tb. The array still shows up on my Mac, but only showing a 3tb size. Disk utility on Mac shows the drive as a 4tb drive, but with only a 3tb partition. I've tried using disk utility to expand the partition to 4tb, but it always reverts to 3tb. I know I could always delete the entire array (I have good backups) and rebuild from scratch, but don't want to go through the hassles if I can help it! Any ideas? Thanks!

Posted on Mar 17, 2013 12:42 PM

by eljonco,Solvedanswer
eljonco eljonco
Level 1 (34 points)
A:

I had foreseen such trouble, so when I received a fresh R6 x 1TB, I decided to experiment a bit. I deleted the factory installed 6-disk RAID5, had a 4-disk RAID5, a single global spare and a single disk partitioned and formatted by the Pegasus Utility as 500 MB. When extending the 500 MB to 1 TB, using the Promise utility, the utility says the logical drive has 1TB capacity.

As you indicate, Disk Utility cannot expand to the full 1TB logical drive size.

 

So part of the answer is 'it is independent of RAID configuration'.

 

To save other people the trouble of testing, I decided to consider my options.

 

To test if it has to do with the formatting by Pegasus Utility, I deleted the logical drive and made a new logical 500GB drive, this time with the 'format' option OFF. I then partitioned the 500 GB logical drive using Disk Utility and set it to 500 GB. In the Promise utility, I started the Background Activities Migration option and expanded the RAID0 500 GB volume to 1000GB. diskutil list shows

Screen Shot 2013-12-25 at 20131225 14.58.10.png

Unfortunately, Disk Utility still fails to extend the current partition layout from 500 GB to 1 TB. Restarting the subsystem/MacOS did not help.

 

Re-partitioning the logical volume in Disk Utility (and thus wiping all data on the partition) DOES work however. So it is "just" MacOS/Disk Utility not being able to expand the already present partition.

 

I notice that if you create another logical drive on the remaining space of the disk, it appears as a new partition on a new disk in Disk Utility(screenshot above then shows /dev/disk3/), not as a second partition on the same disk (as would have been the case on an internal disk or USB/FireWire external single disk). This even happens when you create both partitions on the same disk array at the same time.

Using diskutil I found out that even though Pegasus Utility and Disk Utility both report disk capacity to be 1 TB,

 

     diskutil resizeVolume disk2s2 limits

 

shows

 

     Current size:  499.7 GB (499656028160 Bytes)

     Minimum size:  5.8 GB (5816856576 Bytes)

     Maximum size:  499.7 GB (499656028160 Bytes)

 

The only way one can use the maximum capacity of new disks, seems to remove disk 6 from a 6-disk RAID5 (net capacity 5 TB), copy 1 TB to the now externally attached 1TB disk, swap disk 6 (auto rebuild off) with a 4 TB disk, copy all data to the 4TB disk, swap the remaining 5 disk with 4TB disks, make them RAID0, copy from disk 6 to RAID and then upgrade from RAID0 to RAID5 by adding disk 6 to the RAID. This adds redundancy but does not change the maximum disk size, hence does not require resizing the partition.

Finally copy the 1TB disk content back to the now 20 TB RAID5.

Posted on Dec 25, 2013 6:11 AM

Close
Jerryrigged

Q: Promise Pegasus: migrated to larger array, Mac still sees smaller array.

  • All replies
  • Helpful answers

  • by Eyezest,

    Eyezest Eyezest Jun 20, 2013 4:53 AM in response to Jerryrigged
    Level 1 (0 points)
    Jun 20, 2013 4:53 AM in response to Jerryrigged

    I have the same problem. Have you found a solution? Can anyone help with this?

     

    Many thanks.

  • by eljonco,Solvedanswer

    eljonco eljonco Dec 25, 2013 6:11 AM in response to Jerryrigged
    Level 1 (34 points)
    Dec 25, 2013 6:11 AM in response to Jerryrigged

    I had foreseen such trouble, so when I received a fresh R6 x 1TB, I decided to experiment a bit. I deleted the factory installed 6-disk RAID5, had a 4-disk RAID5, a single global spare and a single disk partitioned and formatted by the Pegasus Utility as 500 MB. When extending the 500 MB to 1 TB, using the Promise utility, the utility says the logical drive has 1TB capacity.

    As you indicate, Disk Utility cannot expand to the full 1TB logical drive size.

     

    So part of the answer is 'it is independent of RAID configuration'.

     

    To save other people the trouble of testing, I decided to consider my options.

     

    To test if it has to do with the formatting by Pegasus Utility, I deleted the logical drive and made a new logical 500GB drive, this time with the 'format' option OFF. I then partitioned the 500 GB logical drive using Disk Utility and set it to 500 GB. In the Promise utility, I started the Background Activities Migration option and expanded the RAID0 500 GB volume to 1000GB. diskutil list shows

    Screen Shot 2013-12-25 at 20131225 14.58.10.png

    Unfortunately, Disk Utility still fails to extend the current partition layout from 500 GB to 1 TB. Restarting the subsystem/MacOS did not help.

     

    Re-partitioning the logical volume in Disk Utility (and thus wiping all data on the partition) DOES work however. So it is "just" MacOS/Disk Utility not being able to expand the already present partition.

     

    I notice that if you create another logical drive on the remaining space of the disk, it appears as a new partition on a new disk in Disk Utility(screenshot above then shows /dev/disk3/), not as a second partition on the same disk (as would have been the case on an internal disk or USB/FireWire external single disk). This even happens when you create both partitions on the same disk array at the same time.

    Using diskutil I found out that even though Pegasus Utility and Disk Utility both report disk capacity to be 1 TB,

     

         diskutil resizeVolume disk2s2 limits

     

    shows

     

         Current size:  499.7 GB (499656028160 Bytes)

         Minimum size:  5.8 GB (5816856576 Bytes)

         Maximum size:  499.7 GB (499656028160 Bytes)

     

    The only way one can use the maximum capacity of new disks, seems to remove disk 6 from a 6-disk RAID5 (net capacity 5 TB), copy 1 TB to the now externally attached 1TB disk, swap disk 6 (auto rebuild off) with a 4 TB disk, copy all data to the 4TB disk, swap the remaining 5 disk with 4TB disks, make them RAID0, copy from disk 6 to RAID and then upgrade from RAID0 to RAID5 by adding disk 6 to the RAID. This adds redundancy but does not change the maximum disk size, hence does not require resizing the partition.

    Finally copy the 1TB disk content back to the now 20 TB RAID5.

  • by eljonco,

    eljonco eljonco Dec 25, 2013 6:33 AM in response to eljonco
    Level 1 (34 points)
    Dec 25, 2013 6:33 AM in response to eljonco

    One more note: if one tries to add another 500 GB partition on the drive seen by Disk Utility (it is now 1000 GB after all), the error message pops up "Partition failed with the error: The chosen size is not valid for the chosen file system". Also with smaller sizes this is the case.

    Using FAT file system, the message changes to "MediaKit reports not enough space on device for requested operation." No joy here either.

  • by eljonco,

    eljonco eljonco Jan 3, 2014 11:41 AM in response to Jerryrigged
    Level 1 (34 points)
    Jan 3, 2014 11:41 AM in response to Jerryrigged

    Promise has taken notice and seems to investigate. I'll keep you posted.

  • by GM F,

    GM F GM F Oct 29, 2014 6:45 AM in response to eljonco
    Level 1 (0 points)
    Oct 29, 2014 6:45 AM in response to eljonco

    Yes, Promise has taken notice. And yes, they have taken notice several times!

     

    But they don't see any reason to investigate: No support at all!

  • by kingsleyfromelizabeth bay,

    kingsleyfromelizabeth bay kingsleyfromelizabeth bay Jan 27, 2015 2:29 AM in response to eljonco
    Level 1 (15 points)
    Jan 27, 2015 2:29 AM in response to eljonco

    After swapping out 6 x 3TB to 6x4TB and spending 5 days migrating less than impressed to discover Disk Utility wouldn't resize my partition. I really didn't look forward to formatting and starting again or copying off 7TB of data to external drives so I investigated some other solutions. Played around in Terminal for a while trying to get it working manually, but no avail. So rebooted into Recovery Mode and tried again, but didn't work on the first resize attempt.

     

    However, if I hit 'Repair Disk' on both the partition and the logical drive, and then tried to resize, it worked. Whilst the repair disks didn't actually find any errors, it did mention something about amending the boot partition (wasn't quick enough to copy it down). I'm now rebooted and enjoying the extra space. Hopefully this works for others until there is a better software fix...

     

    KJS

  • by Adoller,

    Adoller Adoller Feb 9, 2015 8:14 PM in response to kingsleyfromelizabeth bay
    Level 1 (0 points)
    Mac OS X
    Feb 9, 2015 8:14 PM in response to kingsleyfromelizabeth bay

    Your second paragraph tip of repairing both logical and physical drives on the Promise R6 raid worked for me.  I used 4 TB drives but the method was just what I did.  Thanks!!