All of a sudden last night my Unraid server went offline. I rebooted it and now when it loads into OS there are 3 disks missing. 

 

Diagnostics attached incase any one can get any clues from this

tower2-diagnostics-20241206-1937.zip

Edited December 6, 20241 yr by chrishorton7

See if the disks are detected din the board BIOS.

ok, *think* I might be getting closer to figuring it out. I wasnt getting one of the drives show up in the BIOS - have unplugged this drive and now the BIOS and Unraid are booting through much quicker (before when that drive was plugged in I was getting lots of clicking sounds etc and it took a while to get to the BIOS setup screen and to load Unraid. So I am guessing that the drive is fault and I will need to replace which is fine.

Now though, when I get into Unraid there are still 3 devices showing as missing (2x 16TB HDs - parity & disk2 and 1x 6TB HD - disk8 - the suspected faulty one).

 

Parity and disk 2 drives are showing in the Unassigned Disk Devices section with a grey box with Array written in it. I'm unable to reselect these devices to assign them to the correct locations (Parity, Disk2). I haven't changed the order of Sata slots when investigating this, so not sure why this is. Attaching a screenshot of the GUI for reference

That suggests disk issues, swap cables between a non-working device and a working one, and see where the issue follows.

Have tried swapping power and sata cables around on a drive that is showing correctly with the drives that are showing in the unassigned disk devices with grey array box. Same result whether I do this via hot swap or with a full reboot. The device still shows up in the unassigned disk devices section - the disk that was working correctly before is shown as missing. So it seems to correctly identify the disk whatever power cable or SATA cable i use - but for Parity and Disk2 whenever it finds them (whatever power cable or SATA cable I seem to use) it shows as unassigned disk devices with grey array box.

I only just noticed the disk log information icon next to the drive in the unassigned disk devices, when selecting this I get:

Dec  7 13:24:33 Tower2 kernel: ata5: SATA max UDMA/133 abar m2048@0x51739000 port 0x51739300 irq 131
Dec  7 13:24:33 Tower2 kernel: ata5: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
Dec  7 13:24:33 Tower2 kernel: ata5.00: ATA-11: ST16000NM001G-2KK103, SN03, max UDMA/133
Dec  7 13:24:33 Tower2 kernel: ata5.00: 31251759104 sectors, multi 16: LBA48 NCQ (depth 32), AA
Dec  7 13:24:33 Tower2 kernel: ata5.00: Features: NCQ-sndrcv
Dec  7 13:24:33 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] 31251759104 512-byte logical blocks: (16.0 TB/14.6 TiB)
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] 4096-byte physical blocks
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] Write Protect is off
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] Mode Sense: 00 3a 00 00
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] Preferred minimum I/O size 4096 bytes
Dec  7 13:24:33 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x20000 SErr 0x0 action 0x0
Dec  7 13:24:33 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:33 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:33 Tower2 kernel: ata5.00: cmd 60/08:88:00:00:00/00:00:00:00:00/40 tag 17 ncq dma 4096 in
Dec  7 13:24:33 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:33 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:33 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 Sense Key : 0x3 [current] 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 CDB: opcode=0x88 88 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00
Dec  7 13:24:33 Tower2 kernel: I/O error, dev sdd, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:24:33 Tower2 kernel: Buffer I/O error on dev sdd, logical block 0, async page read
Dec  7 13:24:33 Tower2 kernel: ata5: EH complete
Dec  7 13:24:33 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x40 SErr 0x0 action 0x0
Dec  7 13:24:33 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:33 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:33 Tower2 kernel: ata5.00: cmd 60/08:30:00:00:00/00:00:00:00:00/40 tag 6 ncq dma 4096 in
Dec  7 13:24:33 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:33 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:33 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 Sense Key : 0x3 [current] 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 CDB: opcode=0x88 88 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00
Dec  7 13:24:33 Tower2 kernel: I/O error, dev sdd, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:24:33 Tower2 kernel: Buffer I/O error on dev sdd, logical block 0, async page read
Dec  7 13:24:33 Tower2 kernel: ata5: EH complete
Dec  7 13:24:33 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x100000 SErr 0x0 action 0x0
Dec  7 13:24:33 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:33 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:33 Tower2 kernel: ata5.00: cmd 60/08:a0:00:00:00/00:00:00:00:00/40 tag 20 ncq dma 4096 in
Dec  7 13:24:33 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:33 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:33 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 Sense Key : 0x3 [current] 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 CDB: opcode=0x88 88 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00
Dec  7 13:24:33 Tower2 kernel: I/O error, dev sdd, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:24:33 Tower2 kernel: Buffer I/O error on dev sdd, logical block 0, async page read
Dec  7 13:24:33 Tower2 kernel: ata5: EH complete
Dec  7 13:24:33 Tower2 kernel: sdd: unable to read partition table
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] Attached SCSI disk
Dec  7 13:24:33 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x40 SErr 0x0 action 0x0
Dec  7 13:24:33 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:33 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:33 Tower2 kernel: ata5.00: cmd 60/08:30:80:ff:bf/00:00:46:07:00/40 tag 6 ncq dma 4096 in
Dec  7 13:24:33 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:33 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:33 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 Sense Key : 0x3 [current] 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#6 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:24:33 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:24:33 Tower2 kernel: ata5: EH complete
Dec  7 13:24:33 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x200000 SErr 0x0 action 0x0
Dec  7 13:24:33 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:33 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:33 Tower2 kernel: ata5.00: cmd 60/08:a8:80:ff:bf/00:00:46:07:00/40 tag 21 ncq dma 4096 in
Dec  7 13:24:33 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:33 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:33 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 Sense Key : 0x3 [current] 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:24:33 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:24:33 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:24:33 Tower2 kernel: ata5: EH complete
Dec  7 13:24:33 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x40000 SErr 0x0 action 0x0
Dec  7 13:24:33 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:33 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:33 Tower2 kernel: ata5.00: cmd 60/08:90:80:ff:bf/00:00:46:07:00/40 tag 18 ncq dma 4096 in
Dec  7 13:24:33 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:33 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:33 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 Sense Key : 0x3 [current] 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:33 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:24:33 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:24:33 Tower2 kernel: ata5: EH complete
Dec  7 13:24:33 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x800000 SErr 0x0 action 0x0
Dec  7 13:24:33 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:33 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:33 Tower2 kernel: ata5.00: cmd 60/08:b8:80:ff:bf/00:00:46:07:00/40 tag 23 ncq dma 4096 in
Dec  7 13:24:33 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:33 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:34 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 Sense Key : 0x3 [current] 
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:24:34 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:24:34 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:24:34 Tower2 kernel: ata5: EH complete
Dec  7 13:24:34 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x80000 SErr 0x0 action 0x0
Dec  7 13:24:34 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:34 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:34 Tower2 kernel: ata5.00: cmd 60/08:98:80:ff:bf/00:00:46:07:00/40 tag 19 ncq dma 4096 in
Dec  7 13:24:34 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:34 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:34 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#19 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#19 Sense Key : 0x3 [current] 
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#19 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#19 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:24:34 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:24:34 Tower2 kernel: ata5: EH complete
Dec  7 13:24:34 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x200000 SErr 0x0 action 0x0
Dec  7 13:24:34 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:34 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:34 Tower2 kernel: ata5.00: cmd 60/08:a8:80:ff:bf/00:00:46:07:00/40 tag 21 ncq dma 4096 in
Dec  7 13:24:34 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:34 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:34 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 Sense Key : 0x3 [current] 
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:34 Tower2 kernel: sd 5:0:0:0: [sdd] tag#21 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:24:34 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:24:34 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:24:34 Tower2 kernel: ata5: EH complete
Dec  7 13:24:49 Tower2 wsdd2[1385]: starting.
Dec  7 13:24:56 Tower2 emhttpd: ST16000NM001G-2KK103_ZL2KGVCC (sdd) 512 31251759104
Dec  7 13:24:56 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x100000 SErr 0x0 action 0x0
Dec  7 13:24:56 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:56 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:56 Tower2 kernel: ata5.00: cmd 60/20:a0:00:00:00/00:00:00:00:00/40 tag 20 ncq dma 16384 in
Dec  7 13:24:56 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:56 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:56 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 Sense Key : 0x3 [current] 
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 CDB: opcode=0x88 88 00 00 00 00 00 00 00 00 00 00 00 00 20 00 00
Dec  7 13:24:56 Tower2 kernel: I/O error, dev sdd, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 4 prio class 2
Dec  7 13:24:56 Tower2 kernel: ata5: EH complete
Dec  7 13:24:56 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x400 SErr 0x0 action 0x0
Dec  7 13:24:56 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:24:56 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:24:56 Tower2 kernel: ata5.00: cmd 60/08:50:00:00:00/00:00:00:00:00/40 tag 10 ncq dma 4096 in
Dec  7 13:24:56 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:24:56 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:24:56 Tower2 emhttpd: error: ckmbr, 2290: Input/output error (5): read: /dev/sdd
Dec  7 13:24:56 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#10 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#10 Sense Key : 0x3 [current] 
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#10 ASC=0x11 ASCQ=0x4 
Dec  7 13:24:56 Tower2 kernel: sd 5:0:0:0: [sdd] tag#10 CDB: opcode=0x88 88 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00
Dec  7 13:24:56 Tower2 kernel: I/O error, dev sdd, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:24:56 Tower2 kernel: Buffer I/O error on dev sdd, logical block 0, async page read
Dec  7 13:24:56 Tower2 kernel: ata5: EH complete
Dec  7 13:24:56 Tower2 emhttpd: read SMART /dev/sdd
Dec  7 13:24:56 Tower2 wsdd2[1385]: 'Terminated' signal received.
Dec  7 13:24:56 Tower2 wsdd2[1385]: terminating.
Dec  7 13:24:59 Tower2 root:                  /usr/sbin/wsdd2 -d -4
Dec  7 13:24:59 Tower2 wsdd2[5333]: starting.
Dec  7 13:25:01 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x40000 SErr 0x0 action 0x0
Dec  7 13:25:01 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:25:01 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:25:01 Tower2 kernel: ata5.00: cmd 60/08:90:80:ff:bf/00:00:46:07:00/40 tag 18 ncq dma 4096 in
Dec  7 13:25:01 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:25:01 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:25:01 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 Sense Key : 0x3 [current] 
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 ASC=0x11 ASCQ=0x4 
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:25:01 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:25:01 Tower2 kernel: ata5: EH complete
Dec  7 13:25:01 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x8000 SErr 0x0 action 0x0
Dec  7 13:25:01 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:25:01 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:25:01 Tower2 kernel: ata5.00: cmd 60/08:78:80:ff:bf/00:00:46:07:00/40 tag 15 ncq dma 4096 in
Dec  7 13:25:01 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:25:01 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:25:01 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#15 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#15 Sense Key : 0x3 [current] 
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#15 ASC=0x11 ASCQ=0x4 
Dec  7 13:25:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#15 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:25:01 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:25:01 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:25:01 Tower2 kernel: ata5: EH complete
Dec  7 13:26:02 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x100000 SErr 0x0 action 0x0
Dec  7 13:26:02 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:26:02 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:26:02 Tower2 kernel: ata5.00: cmd 60/08:a0:80:ff:bf/00:00:46:07:00/40 tag 20 ncq dma 4096 in
Dec  7 13:26:02 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:26:02 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:26:02 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 Sense Key : 0x3 [current] 
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 ASC=0x11 ASCQ=0x4 
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#20 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:26:02 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:26:02 Tower2 kernel: ata5: EH complete
Dec  7 13:26:02 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x40000 SErr 0x0 action 0x0
Dec  7 13:26:02 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:26:02 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:26:02 Tower2 kernel: ata5.00: cmd 60/08:90:80:ff:bf/00:00:46:07:00/40 tag 18 ncq dma 4096 in
Dec  7 13:26:02 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:26:02 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:26:02 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 Sense Key : 0x3 [current] 
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 ASC=0x11 ASCQ=0x4 
Dec  7 13:26:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:26:02 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:26:02 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:26:02 Tower2 kernel: ata5: EH complete
Dec  7 13:27:01 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x10000 SErr 0x0 action 0x0
Dec  7 13:27:01 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:27:01 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:27:01 Tower2 kernel: ata5.00: cmd 60/08:80:80:ff:bf/00:00:46:07:00/40 tag 16 ncq dma 4096 in
Dec  7 13:27:01 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:27:01 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:27:01 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:27:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#16 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:27:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#16 Sense Key : 0x3 [current] 
Dec  7 13:27:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#16 ASC=0x11 ASCQ=0x4 
Dec  7 13:27:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#16 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:27:01 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:27:01 Tower2 kernel: ata5: EH complete
Dec  7 13:27:01 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x100 SErr 0x0 action 0x0
Dec  7 13:27:01 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:27:01 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:27:01 Tower2 kernel: ata5.00: cmd 60/08:40:80:ff:bf/00:00:46:07:00/40 tag 8 ncq dma 4096 in
Dec  7 13:27:01 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:27:01 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:27:02 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:27:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:27:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 Sense Key : 0x3 [current] 
Dec  7 13:27:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 ASC=0x11 ASCQ=0x4 
Dec  7 13:27:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:27:02 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:27:02 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:27:02 Tower2 kernel: ata5: EH complete
Dec  7 13:28:01 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x20000 SErr 0x0 action 0x0
Dec  7 13:28:01 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:28:01 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:28:01 Tower2 kernel: ata5.00: cmd 60/08:88:80:ff:bf/00:00:46:07:00/40 tag 17 ncq dma 4096 in
Dec  7 13:28:01 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:28:01 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:28:01 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 Sense Key : 0x3 [current] 
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 ASC=0x11 ASCQ=0x4 
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#17 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:28:01 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:28:01 Tower2 kernel: ata5: EH complete
Dec  7 13:28:01 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x100 SErr 0x0 action 0x0
Dec  7 13:28:01 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:28:01 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:28:01 Tower2 kernel: ata5.00: cmd 60/08:40:80:ff:bf/00:00:46:07:00/40 tag 8 ncq dma 4096 in
Dec  7 13:28:01 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:28:01 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:28:01 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 Sense Key : 0x3 [current] 
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 ASC=0x11 ASCQ=0x4 
Dec  7 13:28:01 Tower2 kernel: sd 5:0:0:0: [sdd] tag#8 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:28:01 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:28:01 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:28:01 Tower2 kernel: ata5: EH complete
Dec  7 13:29:02 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x40000 SErr 0x0 action 0x0
Dec  7 13:29:02 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:29:02 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:29:02 Tower2 kernel: ata5.00: cmd 60/08:90:80:ff:bf/00:00:46:07:00/40 tag 18 ncq dma 4096 in
Dec  7 13:29:02 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:29:02 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:29:02 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 Sense Key : 0x3 [current] 
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 ASC=0x11 ASCQ=0x4 
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#18 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:29:02 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:29:02 Tower2 kernel: ata5: EH complete
Dec  7 13:29:02 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0
Dec  7 13:29:02 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:29:02 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:29:02 Tower2 kernel: ata5.00: cmd 60/08:00:80:ff:bf/00:00:46:07:00/40 tag 0 ncq dma 4096 in
Dec  7 13:29:02 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:29:02 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:29:02 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#0 Sense Key : 0x3 [current] 
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#0 ASC=0x11 ASCQ=0x4 
Dec  7 13:29:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#0 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:29:02 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:29:02 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:29:02 Tower2 kernel: ata5: EH complete
Dec  7 13:30:01 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x800000 SErr 0x0 action 0x0
Dec  7 13:30:01 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:30:01 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:30:01 Tower2 kernel: ata5.00: cmd 60/08:b8:80:ff:bf/00:00:46:07:00/40 tag 23 ncq dma 4096 in
Dec  7 13:30:01 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:30:01 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:30:02 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 Sense Key : 0x3 [current] 
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 ASC=0x11 ASCQ=0x4 
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#23 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:30:02 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Dec  7 13:30:02 Tower2 kernel: ata5: EH complete
Dec  7 13:30:02 Tower2 kernel: ata5.00: exception Emask 0x0 SAct 0x2 SErr 0x0 action 0x0
Dec  7 13:30:02 Tower2 kernel: ata5.00: irq_stat 0x40000008
Dec  7 13:30:02 Tower2 kernel: ata5.00: failed command: READ FPDMA QUEUED
Dec  7 13:30:02 Tower2 kernel: ata5.00: cmd 60/08:08:80:ff:bf/00:00:46:07:00/40 tag 1 ncq dma 4096 in
Dec  7 13:30:02 Tower2 kernel: ata5.00: status: { DRDY SENSE ERR }
Dec  7 13:30:02 Tower2 kernel: ata5.00: error: { UNC }
Dec  7 13:30:02 Tower2 kernel: ata5.00: configured for UDMA/133
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#1 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=0s
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#1 Sense Key : 0x3 [current] 
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#1 ASC=0x11 ASCQ=0x4 
Dec  7 13:30:02 Tower2 kernel: sd 5:0:0:0: [sdd] tag#1 CDB: opcode=0x88 88 00 00 00 00 07 46 bf ff 80 00 00 00 08 00 00
Dec  7 13:30:02 Tower2 kernel: I/O error, dev sdd, sector 31251758976 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Dec  7 13:30:02 Tower2 kernel: Buffer I/O error on dev sdd, logical block 3906469872, async page read
Dec  7 13:30:02 Tower2 kernel: ata5: EH complete

From a quick google of some of the errors I've seen recommendations to run smartctl -a /dev/sd[x]

which I have done, I am getting the following:

 

=== START OF INFORMATION SECTION ===
Model Family:     Seagate Exos X16
Device Model:     ST16000NM001G-2KK103
Serial Number:    ZL2KGVCC
LU WWN Device Id: 5 000c50 0dbe4c3e2
Firmware Version: SN03
User Capacity:    16,000,900,661,248 bytes [16.0 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    7200 rpm
Form Factor:      3.5 inches
Device is:        In smartctl database 7.3/5601
ATA Version is:   ACS-4 (minor revision not indicated)
SATA Version is:  SATA 3.3, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Sat Dec  7 13:31:58 2024 PST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

Read SMART Data failed: scsi error badly formed scsi parameters

=== START OF READ SMART DATA SECTION ===
SMART Status command failed: scsi error badly formed scsi parameters
SMART overall-health self-assessment test result: UNKNOWN!
SMART Status, Attributes and Thresholds cannot be read.

Read SMART Log Directory failed: scsi error badly formed scsi parameters

Read SMART Error Log failed: scsi error badly formed scsi parameters

Read SMART Self-test Log failed: scsi error badly formed scsi parameters

Selective Self-tests/Logging not supported

The above only provides legacy SMART information - try 'smartctl -x' for more

13 hours ago, chrishorton7 said:

ame result whether I do this via hot swap or with a full reboot.

That suggests the disk failed.

ok - maybe I'm clutching at straws here but struggling to understand how 3 drives would just fail overnight.

Before I panic and spend a load to buy new drives - any suggestions on anything I can do to try and retain the data?

If you swap both cables from as known good drive with one that is not working, and it still does not show up correctly, it likely failed, not much more you can do.

So any advice on how I would look to try and rebuild & try and retain as much data as possible given I have:

Parity - 16TB - Potentially failed
Disk 1 - 16TB - Ok

Disk 2 - 16TB - Potentially failed

Disk 3 - 16TB - Ok

Disk 4 - 6TB - OK

Disk 5 - 6TB - Ok

Disk 6 - 6TB - Ok

Disk 7 - 6TB - Ok

Disk 8 - 6TB - Potentially failed - the device that was making clicking sounds and slowing boot etc

You can do a new config without the missing drives to recover the data from the other ones.

 

Then, and as a last ditch effort, you can try running ddrescue on the old disk2 and disk8 to see if anything can be recovered.

Interesting thing just happened - I reconnected all drives and booted up with the intention to look at the new config. When booting the same two drives (Parity & Disk2) were showing as unassigned - I have removed Disk8 physically from the server as the clicking sounds definitely dont sound right to me. This time though Disk5 was showing in the unassigned list with grey Array box. I then tested the power splitter to the HD which was fine, and experimented by swapping to a different spare sata splitter end - I think I tried two or three different power ends and then the disk showed up fine as Disk5.

Before I do the new config, could this potentially point to a different issue than the disks failing?

I have ordered all new SATA cables which will be here tomorrow just incase any of those are at fault - so will try all new cables across all drives and boot it up, but now wondering whether it could be something with the splitter cables of PSU? It is a Seasonic Focus GX-750 Modular PSU and I have 4x RB55 cables (6 pin Module to PSU and 4 power cables on it).

10 hours ago, chrishorton7 said:

but now wondering whether it could be something with the splitter cables of PSU?

It could, but doesn't make much sense if you tried a disk that is not working with a known good cable.

Quote

You can do a new config without the missing drives to recover the data from the other ones.

Are you able to walk me through the steps here so I don't royally fuck anything up?

For example when I go to New Config - what do I select in preserve current assignments? Should I disconnect completely the two drives that are showing in the unassigned list, or leave these connected? I have two brand new drives that have arrived that I am going to use once I've got this back into shape - 1 will be parity, the other a data drive - do I run through the new config, get all other ok disks running with no parity set, then add the two new drives and set one as parity?

You can keep all the assignments, this way the drives that are detected will remain assigned, then just start the array.