RN 10400 (OS 6.10.2) switching to Flex-Raid after drive failure and could not switch back to X-Raid

[itsme_356]

I have a ReadyNAS 104 with OS 6.10.2 equipped with 2TB - 4TB - 4TB - 4TB in X-Raid configuration. Last week one of the 4TB HDD went offline due to a disk failure.  After the disk failure I have restarted the NAS and the system tried to resync the 4TB drive. After the resync failed, I notice that the X-raid button was grey.

I replaced the failed 4TB with a 6TB drive and after the drive was resynced I tried to switch the NAS back to X-Raid; however, I received a message that "You are attempting to switch from Flex-RAID to X_RAID.  This is not possible because you have expanded volumes".  The NAS was now equipped with 2TB - 4TB - 4TB - 6TB.

To limit the unused space, I have also replaced the 2TB drive with a 6TB space.  The intention was to increase the NAS storage capacity to 12.9TB as in the attached file.  After the second 6TB HDD was also resynced, I still could switch from Flex-RAID to X-RAID.  When every I select the X-RAID button I obtain the same message as above.  The NAS is also only reporting capacity of 9.08TB instead of the 10.9TB in a Flex-RAID configuration.

 The NAS volume tab is now shown RAID Group #1 (SATA 5900 RPM) and RAID Group #2 (SATA 5900 RPM).  Refer to attached file for the make up of the RAID Groups.

Kindly advise a procedure how I can switch my ReadyNAS back to X-RAID.  I have just invested in two new 6TB HDD and I would like to make good use of it.

[StephenB]

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@itsme_356 wrote:

Kindly advise a procedure how I can switch my ReadyNAS back to X-RAID.  I have just invested in two new 6TB HDD and I would like to make good use of it.

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I don't think you can switch it back at this point.  You could back up the data, and do a factory default with all drives in place.  Then reconfigure the NAS and restore the data from backup.  You could also try paid support (via my.netgear.com).  They might be able to resolve it.

However, you should be able to accomplish your goal with FlexRAID - see below.

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@itsme_356 wrote:

The NAS is also only reporting capacity of 9.08TB instead of the 10.9TB in a Flex-RAID configuration.

 The NAS volume tab is now shown RAID Group #1 (SATA 5900 RPM) and RAID Group #2 (SATA 5900 RPM).  Refer to attached file for the make up of the RAID Groups.

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9.08 TiB is 10 TB.  RAID Group 1 is 4x2TB (and carries over from when you had the 2 TB drives installed.  That accounts for 6 TB of space.  RAID Group 2 is 3x2TB (and gives you the other 4 TB of space).  That group didn't expand when you added upgraded drive 1 to 6 TB.

To get all the available space, there are three steps you can take in flexraid:

1. Expand RAID Group 2 to 4x2TB (increasing that group to 6 TB of space).
2. Create RAID Group 3 as 2x2TB RAID-1 (using the remaining space on disk 1 and disk 4).
3. Concatenate RAID Group 3 to the data volume (adding 2 more TB of space)   

When done, you'd have 14 TB of space (shown as ~12.7 TB by the NAS).

Information on how to do this is in the FlexRAID Optimization Guide: https://www.downloads.netgear.com/files/GDC/READYNAS-100/ReadyNAS_FlexRAID_Optimization_Guide.pdf

Full disclosure: I haven't tried these steps myself (I am using XRAID).

But per page 7, you

1. Select RAID Group 2 in the pulldown. 
2. Select disk 1
3. You should see the "Expand" control - and click on that.

After that completes, you use the instructions on page 8 for steps 2 and 3. 

1. Selecting disks 1 and 4
2. Add Group should appear, so click on that.
3. You want to add a RAID-1 group, and you need to click on the "Concatenated" Radio button.