Due to moving, I can't run my unRAID server for the near future. Most of my data is on two of the drives in my array though, and my workstation has two "hot swap tray" bays (not really hot swap, but means no side panels have to be messed with). Figured this was lucky, as I know all my drives in the pool are just xfs, and I know exactly which of my drives is which physically and in unraid.
Threw them into the workstation, Ubuntu 16.04 LTS, and found that it won't mount the damn things. Running `syslog | tail` after trying shows the following, for both sdb, sdb1, sdc and sdc1 (the two drives in question, with one partition each).
┌─[ $ ]─[ k2trf@desktop ]───[ Wed Dec 27 | 23:43:58 ]───[ ~ ]
└─> dmesg | tail
[ 41.296933] userif-3: sent link up event.
[ 43.913444] userif-3: sent link down event.
[ 43.913451] userif-3: sent link up event.
[ 79.096560] sdb: sdb1
[ 79.098099] sdc: sdc1
[ 372.615530] SGI XFS with ACLs, security attributes, realtime, no debug enabled
[ 381.557248] sdb: sdb1
[ 381.559387] sdc: sdc1
[ 667.199182] XFS (sdb1): Invalid superblock magic number
[ 681.848472] XFS (sdb): Invalid superblock magic number
I am running (or I suppose was since it isn't currently up...) a 6.4 prerelease. I'd just updated as much as I could before the final shutdown, I want to say 6.4_rc17? That may not be right, but it's a close ballpark. I know for fact all the array drives were xfs (the system was initialized well back, sometime just prior to 6.2 IIRC), and all my drives have a relatively low pwron hours, with no SMART issues, nominal health, etc. before the final shutdown. They're both 1TB HGST 2.5" drives (R610 only slots 2.5" sadly), so I'm not entirely sure what to make of it.
Installed xfsdump and xfsprogs, as I realized I didn't have them, and rebooted, but the tail shows the same. I've not tried reading the disks directly like this prior, but was aware that it was a fairly simple matter, especially with ubuntu on the workstation. The ACL/security flag has me a bit concerned, as I didn't recall setting up anything of the sort under unraid. Hoping I'm just missing something, possibly related to being in a 6.4 pre-release!
If anyone has any insight into what might be tripping me up, I'm happily all ears!