NV+ slows after 15-20 minutes [SOLVED]

I have run some tests on the new Duo. It is noticeably quicker than my NV+ and I successfully restored a 21MB archive in about 30 minutes on firmware 4.1.6

I have moved onto 4.1.7 and am running that restore again, all seems to be progressing well. My plan was to move the Duo onto 4.1.13 and then repeqat the upgrade path on the NV+

Having drunk too much coffee I decided to just work my way through all the logs and see if there was anything that couold be of interest. I have posted my partition.log below; it looks to me as though one of my 2TB hard disks has lost its partition table. I presume that will wreak havoc with internal processes as the NV+ tried to pull data from a disk with no partition, then it has to go to another part of the raid array to get the data.

Does this make sense, and what's the best way to recreate the partition structure on the problem disk. Do I simply hot remove and replace and let it rebuild the RAID array, or is there a better method / command that reduces the risk of data loss (I have 3.0TB used from 5.4TB available from 4 x 2TB drives.

I assume hde corresponds to disk 2, second from the left ?

Disk /dev/hde doesn't contain a valid partition table

Disk /dev/hdc: 2000.3 GB, 2000388448256 bytes
255 heads, 63 sectors/track, 243200 cylinders, total 3907008688 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/hdc1              32     4096031     2048000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/hdc2         4096032     4608031      256000   82  Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/hdc3         4608032  3907008687  1951200328    5  Extended
/dev/hdc5         4608040   156280863    75836412   8e  Linux LVM
/dev/hdc6       156280872  3906992311  1875355720   8e  Linux LVM

Disk /dev/hde: 2000.3 GB, 2000388448256 bytes
255 heads, 63 sectors/track, 243200 cylinders, total 3907008688 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x00000000


Disk /dev/hdg: 2000.3 GB, 2000388448256 bytes
255 heads, 63 sectors/track, 243200 cylinders, total 3907008688 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/hdg1              32     4096031     2048000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/hdg2         4096032     4608031      256000   82  Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/hdg3         4608032  3907008687  1951200328    5  Extended
/dev/hdg5         4608040  3906992303  1951192132   8e  Linux LVM

Disk /dev/hdi: 2000.3 GB, 2000388448256 bytes
255 heads, 63 sectors/track, 243200 cylinders, total 3907008688 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/hdi1              32     4096031     2048000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/hdi2         4096032     4608031      256000   82  Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/hdi3         4608032  3907008687  1951200328    5  Extended
/dev/hdi5         4608040  3906992303  1951192132   8e  Linux LVM

and an extract from system.log

Mar  6 17:25:58 RND4000 kernel: VERSION/ID    : SB=(V:0.1.0) ID=<a2015108.00000000.00000000.00000000> CT:4f7b94f2
Mar  6 17:25:58 RND4000 kernel: RAID_INFO     : DISKS(TOTAL:4 RAID:4 PARITY:1 ONL:4 WRK:4 FAILED:0 SPARE:0 BASE:0)
Mar  6 17:25:58 RND4000 kernel:                 SZ:3907008688 UT:00000000 STATE:0 LUNS:2 EXTCMD:1 LSZ:3907008686
Mar  6 17:25:58 RND4000 kernel: LOGICAL_DRIVE : 0: B:0000000032 E:0004096000 R:1 O:1 I:1:000000000 DM:f
Mar  6 17:25:58 RND4000 kernel: LOGICAL_DRIVE : 1: B:0004096032 E:3902912686 R:4 O:1 I:1:000000000 DM:f
Mar  6 17:25:58 RND4000 kernel: PHYSICAL_DRIVE: 0: DISK<N:0/1,hdc(22,0),ID:0,PT:1,SZ:3907008688,ST: B:online>
Mar  6 17:25:58 RND4000 kernel: PHYSICAL_DRIVE: 1: DISK<N:1/2,hde(33,0),ID:1,PT:1,SZ:3907008688,ST:P :online>
Mar  6 17:25:58 RND4000 kernel: PHYSICAL_DRIVE: 2: DISK<N:2/3,hdg(34,0),ID:2,PT:1,SZ:3907008688,ST:  :online>
Mar  6 17:25:58 RND4000 kernel: PHYSICAL_DRIVE: 3: DISK<N:3/4,hdi(56,0),ID:3,PT:1,SZ:3907008688,ST:  :online>
Mar  6 17:25:58 RND4000 kernel: CURRENT_DRIVE : DISK<N:0/1,XXX(22,0),ID:0,PT:1,SZ:3907008688,ST: B:online>
Mar  6 17:25:58 RND4000 kernel: Need to do drives searching.
Mar  6 17:25:58 RND4000 kernel: Find p d at 1, chn 1
Mar  6 17:25:58 RND4000 kernel: Total=4; raid=4; ready=0; work=4; failed=0
Mar  6 17:25:58 RND4000 kernel: Check degraded mode, start_pos=1
Mar  6 17:25:58 RND4000 kernel: No drive missing, X_RAID run in opt mode.
Mar  6 17:25:58 RND4000 kernel: Change X_RAID running mode from 0 to 1
Mar  6 17:25:58 RND4000 kernel: ::::Update backup SB.
Mar  6 17:25:58 RND4000 kernel: X_RAID: recovery thread got woken up ...
Mar  6 17:25:58 RND4000 kernel: New = 1, source drives = f, current/active=4/4
Mar  6 17:25:58 RND4000 kernel: :<6> hdc: hdc1 hdc2 hdc3 < hdc5 hdc6 >
Mar  6 17:25:58 RND4000 kernel: :<6> hde: unknown partition table
Mar  6 17:25:58 RND4000 kernel: :<6> hdg: hdg1 hdg2 hdg3 < hdg5 >
Mar  6 17:25:58 RND4000 kernel: :<6> hdi: hdi1 hdi2 hdi3 < hdi5 >