Replaced failing disk in NV+ v2 - both volume expansion and volume scan fail

And the relevant part of system.log:

Sep 14 14:39:13 The_Library kernel: md: md2: recovery done.
Sep 14 14:39:13 The_Library kernel: md: recovery of RAID array md1
Sep 14 14:39:13 The_Library kernel: md: minimum _guaranteed_  speed: 1000 KB/sec/disk.
Sep 14 14:39:13 The_Library kernel: md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for recovery.
Sep 14 14:39:13 The_Library kernel: md: using 128k window, over a total of 524276 blocks.
Sep 14 14:39:13 The_Library kernel: RAID5 conf printout:
Sep 14 14:39:13 The_Library kernel:  --- rd:4 wd:4
Sep 14 14:39:13 The_Library kernel:  disk 0, o:1, dev:sda3
Sep 14 14:39:13 The_Library kernel:  disk 1, o:1, dev:sdb3
Sep 14 14:39:13 The_Library kernel:  disk 2, o:1, dev:sdc3
Sep 14 14:39:13 The_Library kernel:  disk 3, o:1, dev:sdd3
Sep 14 14:39:35 The_Library RAIDiator: RAID sync finished on volume C.
Sep 14 14:39:44 The_Library RAIDiator: RAID sync finished on volume C.\n\n[Mon Sep 14 14:39:24 EST 2015]
Sep 14 14:39:47 The_Library kernel: md: md1: recovery done.
Sep 14 14:39:47 The_Library kernel: RAID1 conf printout:
Sep 14 14:39:47 The_Library kernel:  --- wd:4 rd:4
Sep 14 14:39:47 The_Library kernel:  disk 0, wo:0, o:1, dev:sda2
Sep 14 14:39:47 The_Library kernel:  disk 1, wo:0, o:1, dev:sdb2
Sep 14 14:39:47 The_Library kernel:  disk 2, wo:0, o:1, dev:sdc2
Sep 14 14:39:47 The_Library kernel:  disk 3, wo:0, o:1, dev:sdd2
Sep 14 23:36:20 The_Library shutdown[2608]: shutting down for system reboot
Sep 14 23:36:21 The_Library init: Switching to runlevel: 6
Sep 14 23:36:42 The_Library exiting on signal 15
Sep 14 23:39:24 The_Library syslogd 1.5.0#6: restart.
- apparently normal messages trimmed for character limit -
Sep 14 23:39:24 The_Library kernel: tun: Universal TUN/TAP device driver, 1.6
Sep 14 23:39:24 The_Library kernel: tun: (C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>
Sep 14 23:39:24 The_Library kernel: Using Hamming 1-bit ECC for NAND device
Sep 14 23:39:24 The_Library kernel: NAND device: Manufacturer ID: 0xad, Chip ID: 0xf1 (Hynix NAND 128MiB 3,3V 8-bit)
Sep 14 23:39:24 The_Library kernel: Scanning device for bad blocks
Sep 14 23:39:24 The_Library kernel: Bad eraseblock 637 at 0x000004fa0000
Sep 14 23:39:24 The_Library kernel: mtd: no mtd-id
- more apparently normal messages snipped -
Sep 14 23:39:25 The_Library kernel: scsi: waiting for bus probes to complete ...
Sep 14 23:39:25 The_Library kernel: scsi 0:0:0:0: Direct-Access     Seagate  ST4000VN000-1H41 SC46 PQ: 0 ANSI: 5
Sep 14 23:39:25 The_Library kernel: scsi 0:0:1:0: Direct-Access     Seagate  ST4000VN000-1H41 SC46 PQ: 0 ANSI: 5
Sep 14 23:39:25 The_Library kernel: scsi 0:0:2:0: Direct-Access     Seagate  ST3000DM001-1CH1 CC26 PQ: 0 ANSI: 5
Sep 14 23:39:25 The_Library kernel: scsi 0:0:3:0: Direct-Access     Seagate  ST4000VN000-1H41 SC46 PQ: 0 ANSI: 5
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] 7814037168 512-byte logical blocks: (4.00 TB/3.63 TiB)
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] 0-byte physical blocks
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: Attached scsi generic sg0 type 0
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] Write Protect is off
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] Mode Sense: 23 00 10 00
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] 7814037168 512-byte logical blocks: (4.00 TB/3.63 TiB)
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] 0-byte physical blocks
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: Attached scsi generic sg1 type 0
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] Write Protect is off
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] Mode Sense: 23 00 10 00
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] 5860533168 512-byte logical blocks: (3.00 TB/2.72 TiB)
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] 0-byte physical blocks
Sep 14 23:39:25 The_Library kernel:  sda:
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: Attached scsi generic sg2 type 0
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] 7814037168 512-byte logical blocks: (4.00 TB/3.63 TiB)
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] 0-byte physical blocks
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: Attached scsi generic sg3 type 0
Sep 14 23:39:25 The_Library kernel: rtc mv_rtc: setting system clock to 2015-09-14 23:37:31 UTC (1442273851)
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] Write cache: enabled, read cache: enabled, supports DPO and FUA
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] Write Protect is off
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] Mode Sense: 23 00 10 00
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] Write Protect is off
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] Mode Sense: 23 00 10 00
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] Write cache: enabled, read cache: enabled, supports DPO and FUA
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] Write cache: enabled, read cache: enabled, supports DPO and FUA
Sep 14 23:39:25 The_Library kernel:  sdb:
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel:  sdc:
Sep 14 23:39:25 The_Library kernel:  sdd: sda1 sda2 sda3 sda4
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:0:0: [sda] Attached SCSI disk
Sep 14 23:39:25 The_Library kernel:  sdb1 sdb2 sdb3 sdb4
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:1:0: [sdb] Attached SCSI disk
Sep 14 23:39:25 The_Library kernel:  sdd1 sdd2 sdd3 sdd4
Sep 14 23:39:25 The_Library kernel:  sdc1 sdc2 sdc3
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] Sector size 0 reported, assuming 512.
Sep 14 23:39:25 The_Library kernel: sd 0:0:2:0: [sdc] Attached SCSI disk
Sep 14 23:39:25 The_Library kernel: sd 0:0:3:0: [sdd] Attached SCSI disk
Sep 14 23:39:25 The_Library kernel: Freeing init memory: 128K
Sep 14 23:39:25 The_Library kernel: armvpd: module license 'Proprietary' taints kernel.
Sep 14 23:39:25 The_Library kernel: Disabling lock debugging due to kernel taint
Sep 14 23:39:25 The_Library kernel: ReadyNAS Pro VPD device driver init...
Sep 14 23:39:25 The_Library kernel: Tuxera NTFS driver 3011.10.19 [Flags: R/W MODULE].
Sep 14 23:39:25 The_Library kernel: eth0: link down
Sep 14 23:39:25 The_Library kernel: eth0: started
Sep 14 23:39:25 The_Library kernel: ADDRCONF(NETDEV_UP): eth0: link is not ready
Sep 14 23:39:25 The_Library kernel: md: bind<sdb1>
Sep 14 23:39:25 The_Library kernel: md: bind<sdc1>
Sep 14 23:39:25 The_Library kernel: md: bind<sdd1>
Sep 14 23:39:25 The_Library kernel: md: bind<sda1>
Sep 14 23:39:25 The_Library kernel: raid1: raid set md0 active with 4 out of 4 mirrors
Sep 14 23:39:25 The_Library kernel: md0: detected capacity change from 0 to 4293906432
Sep 14 23:39:25 The_Library kernel:  md0: unknown partition table
Sep 14 23:39:25 The_Library kernel: md: bind<sdb2>
Sep 14 23:39:25 The_Library kernel: md: bind<sdc2>
Sep 14 23:39:25 The_Library kernel: md: bind<sdd2>
Sep 14 23:39:25 The_Library kernel: md: bind<sda2>
Sep 14 23:39:25 The_Library kernel: raid1: raid set md1 active with 4 out of 4 mirrors
Sep 14 23:39:25 The_Library kernel: md1: detected capacity change from 0 to 536858624
Sep 14 23:39:25 The_Library kernel:  md1: unknown partition table
Sep 14 23:39:25 The_Library kernel: md: bind<sdb3>
Sep 14 23:39:25 The_Library kernel: md: bind<sdc3>
Sep 14 23:39:25 The_Library kernel: md: bind<sdd3>
Sep 14 23:39:25 The_Library kernel: md: bind<sda3>
Sep 14 23:39:25 The_Library kernel: raid5: device sda3 operational as raid disk 0
Sep 14 23:39:25 The_Library kernel: raid5: device sdd3 operational as raid disk 3
Sep 14 23:39:25 The_Library kernel: raid5: device sdc3 operational as raid disk 2
Sep 14 23:39:25 The_Library kernel: raid5: device sdb3 operational as raid disk 1
Sep 14 23:39:25 The_Library kernel: raid5: allocated 4216kB for md2
Sep 14 23:39:25 The_Library kernel: raid5: raid level 5 set md2 active with 4 out of 4 devices, algorithm 2
Sep 14 23:39:25 The_Library kernel: RAID5 conf printout:
Sep 14 23:39:25 The_Library kernel:  --- rd:4 wd:4
Sep 14 23:39:25 The_Library kernel:  disk 0, o:1, dev:sda3
Sep 14 23:39:25 The_Library kernel:  disk 1, o:1, dev:sdb3
Sep 14 23:39:25 The_Library kernel:  disk 2, o:1, dev:sdc3
Sep 14 23:39:25 The_Library kernel:  disk 3, o:1, dev:sdd3
Sep 14 23:39:25 The_Library kernel: md2: detected capacity change from 0 to 8987273330688
Sep 14 23:39:25 The_Library kernel:  md2: unknown partition table
Sep 14 23:39:25 The_Library kernel: md: bind<sdd4>
Sep 14 23:39:25 The_Library kernel: md: bind<sda4>
Sep 14 23:39:25 The_Library kernel: md: bind<sdb4>
Sep 14 23:39:25 The_Library kernel: raid5: device sdb4 operational as raid disk 0
Sep 14 23:39:25 The_Library kernel: raid5: device sda4 operational as raid disk 2
Sep 14 23:39:25 The_Library kernel: raid5: device sdd4 operational as raid disk 1
Sep 14 23:39:25 The_Library kernel: raid5: allocated 3174kB for md3
Sep 14 23:39:25 The_Library kernel: raid5: raid level 5 set md3 active with 3 out of 3 devices, algorithm 2
Sep 14 23:39:25 The_Library kernel: RAID5 conf printout:
Sep 14 23:39:25 The_Library kernel:  --- rd:3 wd:3
Sep 14 23:39:25 The_Library kernel:  disk 0, o:1, dev:sdb4
Sep 14 23:39:25 The_Library kernel:  disk 1, o:1, dev:sdd4
Sep 14 23:39:25 The_Library kernel:  disk 2, o:1, dev:sda4
Sep 14 23:39:25 The_Library kernel: md3: detected capacity change from 0 to 2000385605632
Sep 14 23:39:25 The_Library kernel:  md3: unknown partition table
Sep 14 23:39:25 The_Library kernel: kjournald starting.  Commit interval 5 seconds
Sep 14 23:39:25 The_Library kernel: EXT3-fs: mounted filesystem with ordered data mode.
Sep 14 23:39:25 The_Library kernel: eth0: link up, full duplex, speed 1 Gbps
Sep 14 23:39:25 The_Library kernel: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Sep 14 23:39:25 The_Library kernel: kjournald starting.  Commit interval 5 seconds
Sep 14 23:39:25 The_Library kernel: EXT3 FS on md0, internal journal
Sep 14 23:39:25 The_Library kernel: EXT3-fs: mounted filesystem with ordered data mode.
Sep 14 23:39:25 The_Library kernel: kjournald starting.  Commit interval 5 seconds
Sep 14 23:39:25 The_Library kernel: EXT3 FS on md0, internal journal
Sep 14 23:39:25 The_Library kernel: EXT3-fs: mounted filesystem with ordered data mode.
Sep 14 23:39:25 The_Library kernel: udevd version 125 started
Sep 14 23:39:25 The_Library kernel: Adding 524268k swap on /dev/md1.  Priority:-1 extents:1 across:524268k 
Sep 14 23:39:25 The_Library kernel: fsck.ext4 invoked oom-killer: gfp_mask=0x200da, order=0, oomkilladj=0
Sep 14 23:39:25 The_Library kernel: [<c002ecf0>] (unwind_backtrace+0x0/0xdc) from [<c009d930>] (oom_kill_process+0x58/0x1b4)
Sep 14 23:39:25 The_Library kernel: [<c009d930>] (oom_kill_process+0x58/0x1b4) from [<c009de84>] (__out_of_memory+0x160/0x180)
Sep 14 23:39:25 The_Library kernel: [<c009de84>] (__out_of_memory+0x160/0x180) from [<c009df08>] (out_of_memory+0x64/0x98)
Sep 14 23:39:25 The_Library kernel: [<c009df08>] (out_of_memory+0x64/0x98) from [<c00a06a4>] (__alloc_pages_nodemask+0x3f0/0x4dc)
Sep 14 23:39:25 The_Library kernel: [<c00a06a4>] (__alloc_pages_nodemask+0x3f0/0x4dc) from [<c00ad338>] (handle_mm_fault+0x130/0x588)
Sep 14 23:39:25 The_Library kernel: [<c00ad338>] (handle_mm_fault+0x130/0x588) from [<c002fcf0>] (do_page_fault+0xe0/0x22c)
Sep 14 23:39:25 The_Library kernel: [<c002fcf0>] (do_page_fault+0xe0/0x22c) from [<c0028230>] (do_DataAbort+0x30/0x90)
Sep 14 23:39:25 The_Library kernel: [<c0028230>] (do_DataAbort+0x30/0x90) from [<c0028f1c>] (ret_from_exception+0x0/0x10)
Sep 14 23:39:25 The_Library kernel: Exception stack(0xcd54ffb0 to 0xcd54fff8)
Sep 14 23:39:25 The_Library kernel: ffa0:                                     5881a008 00000000 01be3004 68e93000 
Sep 14 23:39:25 The_Library kernel: ffc0: ffffffff ffffffff ffffffff 10000000 00000000 00004000 00000000 bee538bc 
Sep 14 23:39:25 The_Library kernel: ffe0: 00000000 bee53898 40040d90 40147be8 20000010 ffffffff                   
Sep 14 23:39:25 The_Library kernel: Mem-info:
Sep 14 23:39:25 The_Library kernel: Normal per-cpu:
Sep 14 23:39:25 The_Library kernel: CPU    0: hi:   90, btch:  15 usd:  14
Sep 14 23:39:25 The_Library kernel: Active_anon:25727 active_file:12 inactive_anon:22013
Sep 14 23:39:25 The_Library kernel:  inactive_file:0 unevictable:2 dirty:0 writeback:8710 unstable:0
Sep 14 23:39:25 The_Library kernel:  free:504 slab:4767 mapped:1 pagetables:360 bounce:0
Sep 14 23:39:25 The_Library kernel: Normal free:2016kB min:2036kB low:2544kB high:3052kB active_anon:102908kB inactive_anon:88052kB active_file:48kB inactive_file:0kB unevictable:8kB present:260096kB pages_scanned:1623 all_unreclaimable? no
Sep 14 23:39:25 The_Library kernel: lowmem_reserve[]: 0 0
Sep 14 23:39:25 The_Library kernel: Normal: 2*4kB 1*8kB 3*16kB 1*32kB 2*64kB 4*128kB 3*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB 0*32768kB 0*65536kB 0*131072kB 0*262144kB 0*524288kB 0*1048576kB = 2016kB
Sep 14 23:39:25 The_Library kernel: 11179 total pagecache pages
Sep 14 23:39:25 The_Library kernel: 11165 pages in swap cache
Sep 14 23:39:25 The_Library kernel: Swap cache stats: add 526194, delete 515029, find 127066/149636
Sep 14 23:39:25 The_Library kernel: Free swap  = 0kB
Sep 14 23:39:25 The_Library kernel: Total swap = 524268kB
Sep 14 23:39:25 The_Library kernel: 65536 pages of RAM
Sep 14 23:39:25 The_Library kernel: 589 free pages
Sep 14 23:39:25 The_Library kernel: 3841 reserved pages
Sep 14 23:39:25 The_Library kernel: 3230 slab pages
Sep 14 23:39:25 The_Library kernel: 19 pages shared
Sep 14 23:39:25 The_Library kernel: 11165 pages swap cached
Sep 14 23:39:25 The_Library kernel: Out of memory: kill process 1656 (fsck.ext4) score 10926 or a child
Sep 14 23:39:25 The_Library kernel: Killed process 1656 (fsck.ext4)
Sep 14 23:39:25 The_Library kernel: EXT4-fs (dm-0): barriers enabled
Sep 14 23:39:25 The_Library kernel: kjournald2 starting: pid 1693, dev dm-0:8, commit interval 5 seconds
Sep 14 23:39:25 The_Library kernel: EXT4-fs (dm-0): internal journal on dm-0:8
Sep 14 23:39:25 The_Library kernel: EXT4-fs: file extents enabled
Sep 14 23:39:25 The_Library kernel: EXT4-fs: mballoc enabled
Sep 14 23:39:25 The_Library kernel: EXT4-fs (dm-0): mounted filesystem with ordered data mode
Sep 14 23:39:51 The_Library syslogd 1.5.0#6: restart.
Sep 14 23:39:53 The_Library ifplugd(eth0)[3782]: ifplugd 0.28 initializing.

Halp!