I am getting a 30-60 second delay every time I switch tabs on the Unraid dashboard which seem to be the result of a hardware error.  The problem is, I don't know how to identify which disk is the issue.  It shows up plainly in the logs:

 

Dec 27 23:30:48 Tower emhttp: shcmd (90): rmmod md-mod |& logger
Dec 27 23:30:48 Tower kernel: md: unRAID driver removed
Dec 27 23:30:48 Tower emhttp: shcmd (91): modprobe md-mod super=/boot/config/super.dat |& logger
Dec 27 23:30:48 Tower kernel: md: unRAID driver 2.6.6 installed
Dec 27 23:30:48 Tower emhttp: Plus key detected, GUID: XXXX-XXXX-31BB-BF50892D0641 FILE: /boot/config/Plus.key
Dec 27 23:30:48 Tower emhttp: Device inventory:
Dec 27 23:30:48 Tower emhttp: shcmd (92): udevadm settle
Dec 27 23:30:48 Tower emhttp: Kingston_DataTraveler_2.0_50E5495131BBBF50892D0641-0:0 (sda) 15364384
Dec 27 23:30:48 Tower emhttp: ST3000DM001-1CH166_W1F22GP5 (sdb) 2930266532
Dec 27 23:30:48 Tower emhttp: TOSHIBA_MD04ACA500_55TAK2CWFS9A (sdc) 4883770532
Dec 27 23:30:49 Tower emhttp: ST3000DM001-1CH166_W1F24BS0 (sdd) 2930266532
Dec 27 23:30:49 Tower emhttp: TOSHIBA_MD04ACA500_6566KAFQFS9A (sde) 4883770532
Dec 27 23:30:49 Tower emhttp: ST5000DM000-1FK178_W4J01V9W (sdf) 4883770532
Dec 27 23:30:49 Tower emhttp: TOSHIBA_MD04ACA500_55TAK2CVFS9A (sdg) 4883770532
Dec 27 23:30:49 Tower emhttp: TOSHIBA_MD04ACA500_55TAK2CUFS9A (sdh) 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (1): import 0 sdc 4883770532 0 TOSHIBA_MD04ACA500_55TAK2CWFS9A
Dec 27 23:30:49 Tower kernel: md: import disk0: (sdc) TOSHIBA_MD04ACA500_55TAK2CWFS9A size: 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (2): import 1 sdh 4883770532 0 TOSHIBA_MD04ACA500_55TAK2CUFS9A
Dec 27 23:30:49 Tower kernel: md: import disk1: (sdh) TOSHIBA_MD04ACA500_55TAK2CUFS9A size: 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (3): import 2 sdg 4883770532 0 TOSHIBA_MD04ACA500_55TAK2CVFS9A
Dec 27 23:30:49 Tower kernel: md: import disk2: (sdg) TOSHIBA_MD04ACA500_55TAK2CVFS9A size: 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (4): import 3 sdb 2930266532 0 ST3000DM001-1CH166_W1F22GP5
Dec 27 23:30:49 Tower kernel: md: import disk3: (sdb) ST3000DM001-1CH166_W1F22GP5 size: 2930266532
Dec 27 23:30:51 Tower kernel: mdcmd (5): import 4 sdf 4883770532 0 ST5000DM000-1FK178_W4J01V9W
Dec 27 23:30:51 Tower kernel: md: import disk4: (sdf) ST5000DM000-1FK178_W4J01V9W size: 4883770532
Dec 27 23:30:51 Tower kernel: mdcmd (6): import 5 sde 4883770532 0 TOSHIBA_MD04ACA500_6566KAFQFS9A
Dec 27 23:30:51 Tower kernel: md: import disk5: (sde) TOSHIBA_MD04ACA500_6566KAFQFS9A size: 4883770532
Dec 27 23:30:51 Tower kernel: mdcmd (7): import 6
Dec 27 23:30:51 Tower kernel: mdcmd (: import 7
Dec 27 23:30:51 Tower kernel: mdcmd (9): import 8
Dec 27 23:30:51 Tower kernel: mdcmd (10): import 9
Dec 27 23:30:51 Tower kernel: mdcmd (11): import 10
Dec 27 23:30:51 Tower kernel: mdcmd (12): import 11
Dec 27 23:30:51 Tower kernel: mdcmd (13): import 12
Dec 27 23:30:51 Tower kernel: mdcmd (14): import 13
Dec 27 23:30:51 Tower kernel: mdcmd (15): import 14
Dec 27 23:30:51 Tower kernel: mdcmd (16): import 15
Dec 27 23:30:51 Tower kernel: mdcmd (17): import 16
Dec 27 23:30:51 Tower kernel: mdcmd (18): import 17
Dec 27 23:30:51 Tower kernel: mdcmd (19): import 18
Dec 27 23:30:51 Tower kernel: mdcmd (20): import 19
Dec 27 23:30:51 Tower kernel: mdcmd (21): import 20
Dec 27 23:30:51 Tower kernel: mdcmd (22): import 21
Dec 27 23:30:51 Tower kernel: mdcmd (23): import 22
Dec 27 23:30:51 Tower kernel: mdcmd (24): import 23
Dec 27 23:30:51 Tower kernel: mdcmd (25): import 24
Dec 27 23:30:51 Tower kernel: mdcmd (26): import 25
Dec 27 23:30:51 Tower kernel: mdcmd (27): import 26
Dec 27 23:30:51 Tower kernel: mdcmd (28): import 27
Dec 27 23:30:51 Tower kernel: mdcmd (29): import 28
Dec 27 23:30:51 Tower kernel: mdcmd (30): import 29
Dec 27 23:30:51 Tower kernel: md: import_slot: 29 empty
Dec 27 23:30:51 Tower emhttp: import 30 cache device: sdd
Dec 27 23:30:51 Tower emhttp: import flash device: sda
Dec 27 23:31:12 Tower kernel: ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
Dec 27 23:31:12 Tower kernel: ata3.00: failed command: SMART
Dec 27 23:31:12 Tower kernel: ata3.00: cmd b0/d0:01:00:4f:c2/00:00:00:00:00/00 tag 14 pio 512 in
Dec 27 23:31:12 Tower kernel: res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
Dec 27 23:31:12 Tower kernel: ata3.00: status: { DRDY }
Dec 27 23:31:12 Tower kernel: ata3: hard resetting link
Dec 27 23:31:17 Tower kernel: ata3: link is slow to respond, please be patient (ready=0)
Dec 27 23:31:20 Tower kernel: ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
Dec 27 23:31:20 Tower kernel: ata3.00: configured for UDMA/133
Dec 27 23:31:20 Tower kernel: ata3: EH complete

 

What in the heck is going on here?

Diagnostics?

In the end I pulled out the server and ripped it apart drive by drive to find the culprit.  It was the cache drive.  For anyone else experiencing this issues here are some clues in the log:

 

Dec 27 23:30:48 Tower emhttp: Kingston_DataTraveler_2.0_50E5495131BBBF50892D0641-0:0 (sda) 15364384
Dec 27 23:30:48 Tower emhttp: ST3000DM001-1CH166_W1F22GP5 (sdb) 2930266532
Dec 27 23:30:48 Tower emhttp: TOSHIBA_MD04ACA500_55TAK2CWFS9A (sdc) 4883770532
Dec 27 23:30:49 Tower emhttp: ST3000DM001-1CH166_W1F24BS0 (sdd) 2930266532
Dec 27 23:30:49 Tower emhttp: TOSHIBA_MD04ACA500_6566KAFQFS9A (sde) 4883770532
Dec 27 23:30:49 Tower emhttp: ST5000DM000-1FK178_W4J01V9W (sdf) 4883770532
Dec 27 23:30:49 Tower emhttp: TOSHIBA_MD04ACA500_55TAK2CVFS9A (sdg) 4883770532
Dec 27 23:30:49 Tower emhttp: TOSHIBA_MD04ACA500_55TAK2CUFS9A (sdh) 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (1): import 0 sdc 4883770532 0 TOSHIBA_MD04ACA500_55TAK2CWFS9A
Dec 27 23:30:49 Tower kernel: md: import disk0: (sdc) TOSHIBA_MD04ACA500_55TAK2CWFS9A size: 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (2): import 1 sdh 4883770532 0 TOSHIBA_MD04ACA500_55TAK2CUFS9A
Dec 27 23:30:49 Tower kernel: md: import disk1: (sdh) TOSHIBA_MD04ACA500_55TAK2CUFS9A size: 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (3): import 2 sdg 4883770532 0 TOSHIBA_MD04ACA500_55TAK2CVFS9A
Dec 27 23:30:49 Tower kernel: md: import disk2: (sdg) TOSHIBA_MD04ACA500_55TAK2CVFS9A size: 4883770532
Dec 27 23:30:49 Tower kernel: mdcmd (4): import 3 sdb 2930266532 0 ST3000DM001-1CH166_W1F22GP5
Dec 27 23:30:49 Tower kernel: md: import disk3: (sdb) ST3000DM001-1CH166_W1F22GP5 size: 2930266532
Dec 27 23:30:51 Tower kernel: mdcmd (5): import 4 sdf 4883770532 0 ST5000DM000-1FK178_W4J01V9W
Dec 27 23:30:51 Tower kernel: md: import disk4: (sdf) ST5000DM000-1FK178_W4J01V9W size: 4883770532
Dec 27 23:30:51 Tower kernel: mdcmd (6): import 5 sde 4883770532 0 TOSHIBA_MD04ACA500_6566KAFQFS9A
Dec 27 23:30:51 Tower kernel: md: import disk5: (sde) TOSHIBA_MD04ACA500_6566KAFQFS9A size: 4883770532
Dec 27 23:30:51 Tower kernel: mdcmd (7): import 6
Dec 27 23:30:51 Tower kernel: mdcmd (: import 7
Dec 27 23:30:51 Tower kernel: mdcmd (9): import 8
Dec 27 23:30:51 Tower kernel: mdcmd (10): import 9
Dec 27 23:30:51 Tower kernel: mdcmd (11): import 10
Dec 27 23:30:51 Tower kernel: mdcmd (12): import 11
Dec 27 23:30:51 Tower kernel: mdcmd (13): import 12
Dec 27 23:30:51 Tower kernel: mdcmd (14): import 13
Dec 27 23:30:51 Tower kernel: mdcmd (15): import 14
Dec 27 23:30:51 Tower kernel: mdcmd (16): import 15
Dec 27 23:30:51 Tower kernel: mdcmd (17): import 16
Dec 27 23:30:51 Tower kernel: mdcmd (18): import 17
Dec 27 23:30:51 Tower kernel: mdcmd (19): import 18
Dec 27 23:30:51 Tower kernel: mdcmd (20): import 19
Dec 27 23:30:51 Tower kernel: mdcmd (21): import 20
Dec 27 23:30:51 Tower kernel: mdcmd (22): import 21
Dec 27 23:30:51 Tower kernel: mdcmd (23): import 22
Dec 27 23:30:51 Tower kernel: mdcmd (24): import 23
Dec 27 23:30:51 Tower kernel: mdcmd (25): import 24
Dec 27 23:30:51 Tower kernel: mdcmd (26): import 25
Dec 27 23:30:51 Tower kernel: mdcmd (27): import 26
Dec 27 23:30:51 Tower kernel: mdcmd (28): import 27
Dec 27 23:30:51 Tower kernel: mdcmd (29): import 28
Dec 27 23:30:51 Tower kernel: mdcmd (30): import 29
Dec 27 23:30:51 Tower kernel: md: import_slot: 29 empty

 

Excluding the boot drive, drives B, C, D, E, F, G, H are listed at the beginning, then only C, H, G, B, F, E are imported...

You may notice D is missing.  This drive was the culprit.  I tried another SATA port, another cable, but in the end the drive seemed to be the issue.  Replace the drive and all is fine.

Possibly you arrived at the correct solution, but posting your complete diagnostics zip would have provided a lot more information to go on. For anyone else that is following the thread, a drive that fails to get imported as this person had does not necessarily indicate a drive failure. Connection issues are much more common than drive failures.