SMART disk errors or NO SMART disk errors?

Can't remember exactly. Google for MAN page.

Something like

smartctl -a /dev/hdc

mdgm wrote:
Can't remember exactly. Google for MAN page.

Found it. Thanks. Also came across a $5 app for OSX that appears to be a front end for smartctl....

@mdgm: Are you sure USB-connected drives can generate SMART alerts?

I have an NV+ with 4x2Tb WD drives (xRAID) and attached 1.5 and 2TB USB drives I use for backups. I have replaced a number of drives in the enclosure over time. More recently Disk 1 has been replaced twice. The original WD Caviar Green drive generated SMART alerts @4am daily:
"Disk 1 did not pass SMART self-assessment...."

I purchased a new Caviar Black, hot-swapped Disk 1 and RMA'ed the defective drive. The new Disk 1 generated alerts from day 1. The replacement RMA'ed drive arrived so I hot-swapped again and had the Caviar Black replaced. The replacement Caviar Green - Disk 1 - has been generating the same alerts from day 1 but looks clean via Frontview:
Model: WDC WD20EARS-00MVWB0
Serial: WD-WCAZA7142785
Firmware: 51.0AB51
SMART Attribute
Raw Read Error Rate 0
Spin Up Time 0
Start Stop Count 4
Reallocated Sector Count 0
Seek Error Rate 0
Power On Hours 138
Spin Retry Count 0
Calibration Retry Count 0
Power Cycle Count 4
Power-Off Retract Count 3
Load Cycle Count 9354
Temperature Celsius 29
Reallocated Event Count 0
Current Pending Sector 0
Offline Uncorrectable 0
UDMA CRC Error Count 0
Multi Zone Error Rate 0
ATA Error Count 0

Extended Attribute
Hot-add events 0
Hot-remove events 0
Lp stat events 39
Power glitches 0
Hard disk resets 0
Retries 0
Repaired sectors 0

I checked /frontview/bin/check_smart_errors on the Readynas via ssh. This is the script that runs @4am daily and it appears to check hd's only not sd's (the USB drives are dev/sda1 and sdb1).

Am I missing something or just having a bad run with hard drives?

Appreciate any answers you can provide as this has been frustrating me for a while now.

That disk is not on the compatibility list for the NV+. Have you tried hooking that disk up to an internal SATA port in your PC and checking that disk using WD LifeGuard Diagnostics?

Actually you a right. I got the enclosure and 4xCaviar Green drives simultaneously from the same supplier. Disks 1, 2 and 3 have been replaced (Disk 3 with a Caviar Black I purchased) and my configuration is now:

Device Description
Disk 1 WDC WD20EARS-00MVWB0 1862 GB , 29 C / 84 F , Write-cache ON OK
Disk 2 WDC WD20EARS-00MVWB0 1862 GB , 33 C / 91 F , Write-cache ON OK
Disk 3 WDC WD2002FAEX-007BA0 1862 GB , 37 C / 98 F , Write-cache ON OK
Disk 4 WDC WD20EARX-00PASB0 1862 GB , 29 C / 84 F , Write-cache ON OK

So looks like the supplier has been sending me incompatible drives as RMA replacements. I will swap out DISK 1 and run the tools, thanks.

Apologies. I found the source of the error. A usb-attached WD MyBook. It seems the script does check SMART stats for usb drives although the results don't appear in the overall log produced by the smartctl that runs at 4am daily (Fatso is the name of my ReadyNAS NV+):

Fatso:/var/log/frontview# cat smart_errors_sdb
OLD_Reallocated_Sector_Ct=885
OLD_ATA_Error_Count=48055
Fatso:/var/log/frontview# mount
/dev/hdc1 on / type ext3 (rw,noatime)
proc on /proc type proc (rw)
devpts on /dev/pts type devpts (rw)
sysfs on /sys type sysfs (rw)
tmpfs on /ramfs type ramfs (rw)
tmpfs on /USB type tmpfs (rw,size=16k)
/dev/c/c on /c type ext3 (rw,noatime,acl,user_xattr,usrquota,grpquota)
/c/backup on /home/ftp/backup type bind (rw,bind)
/c/documents on /home/ftp/documents type bind (rw,bind)
/c/downloads on /home/ftp/downloads type bind (rw,bind)
/c/media on /home/ftp/media type bind (rw,bind)
nfsd on /proc/fs/nfsd type nfsd (rw)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/sdb1 on /USB/MyBook type ext3 (rw,noatime,acl)
/dev/sda1 on /USB/SunBright type ext3 (rw,noatime,acl)