In the process of upgrading a 2 4tb disk RAID 0 array from an iffy LaCie drive to a faster/more reliable USB enclosure I have lost data. The backups take a long, long time to restore so I'm hoping to be able to rebuild the RAID 0 array instead. This is all on a Mac Mini running High Sierra.
It was originally a RAID 0 array in a LaCie Thunderbolt drive, but this kept randomly dropping out so I decided to move the drives into a COTS USB 3 enclosure instead. This was set up as a RAID 1 array with 2 2tb drives and I cloned the LaCie contents onto it as a backup. Then I took the pair of 4tb drives from the LaCie and put them in the USB enclosure and switched it to RAID 0 mode, but the Mac Mini did not recognise them. So then I replaced them in the LaCie enclosure, but they just showed up as 2 different drives which the Mac Mini would not mount. I tried switching the order of the drives, but this did not help. I wasn't worried because I still had my pair of 2tb RAID 1 drives, which I put back in the USB enclosure, switched it to RAID 1 mode and...the Mac Mini would not recognise it. Data gone - and I hadn't even done a single write operation or formatted anything.
I have tried Data Rescue and 321 Soft Raid Recovery to try and recover the LaCie RAID 0 drive, and while I have managed to get a lot of data from the RAID 1 drive, it's just recovered it as a bunch of files with no usable filenames or directory structure.
My offsite backups appear to be incomplete, and in any case are taking literally days to restore.
distil list output: ...$ diskutil list /dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *1.0 TB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_HFS Macintosh HD 999.3 GB disk0s2 3: Apple_Boot Recovery HD 650.0 MB disk0s3 /dev/disk4 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *5.0 TB disk4 1: EFI EFI 209.7 MB disk4s1 2: Apple_HFS HSBACKUP1 5.0 TB disk4s2 /dev/disk5 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: *4.0 TB disk5 /dev/disk6 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: *4.0 TB disk6
/dev/disk 5 and 6 are the elements of the RAID 0 (ignore HSBACKUP1 - that is my offsite backup drive currently doing a restore of most of the company files)
My LaCie enclosure model is a 2big thunderbolt 8tb - comes preconfigured as RAID 0. I didn't install it originally (it was done in 2013) but I assume it was just used with default settings.
So - does anyone know how to rebuild a RAID 0 array on a mac? It hasn't been formatted or written to in any way - just put into another enclosure, taken out and put back into the original.
OUTCOME: Have not succeeded in rebuilding the RAID. Instead between the restores from my offsite backups and £60 for a Data Rescue license, have managed to recover everything that was lost. Lessons learnt: do not use a Mac as a file server, with the best will in the world they're just not built with that in mind, and verify your daily backups to make sure they're backing up everything you need them to, I wouldn't have had any problems at all save that the account doing the backups did not have rights to all the source files.