ReadyNas Duo v2 show SMART status

Question

I have a ReadyNAS Duo with both disks running in an X-RAID configuration.

The reallocated sector count value seems awfully high on one of the ReadyNas disks (see below).

SMART Attribute
Spin Up Time    0
Start Stop Count    8154
Reallocated Sector Count    755    <---------------- HERE
Power On Hours  26065
Spin Retry Count    0
Power Cycle Count   150
Runtime Bad Block   0
End-to-End Error    0
Reported Uncorrect  0
Command Timeout 0
High Fly Writes 0
Airflow Temperature Cel 41
Temperature Celsius 41
Current Pending Sector  0
Offline Uncorrectable   0
UDMA CRC Error Count    0
Head Flying Hours   209242216746761
Total LBAs Written  2201629466
Total LBAs Read 2155180082
ATA Error Count 0

Extended Attribute
Hot-add events  0
Hot-remove events   0
Lp stat events  146
Power glitches  0
Hard disk resets    0
Retries 0
Repaired sectors    0

1) Am I correct in assuming that the X-RAID array with 2 disks is equivalent of a RAID-1 array and my data is safe in case of a single disk failure?

2) The smart status does not tell me the normalized values however, so I have no idea how close to failure the disk is. How can I find the normalized value or the reallocated sector limit when the readynas considers the disk as failed? (How soon will it fail?)

Thanks!

kcrk · Accepted Answer · 2016-04-26T12:38:51.443

I backed everything up on a daily basis, so I didn't break a sweat when the disk failed just now.

Running the smart status a final time I got the following:

Reallocated Sector Count 1002

Answers:

1) All data is fully redundant, X-Raid in the case of this NAS is basically the same as RAID-1. No need for the backup! (I'd take on just in case the second one fails during initialization of the first disk, when the array is not redundant, but that's a question of how much you love your data)

2) It seems that going over 1000 has triggered the SMART status to fail. The normalized values are 76/36 Worst:76 So I don't think it has actually failed catastrophically yet. Even reading a full image of the disk works fine still using dd.

Update: The disk has now catastrophically failed after issuing a SMART Secure erase command. No blocks get read, nothing is written. Disk is dead and getting shredded (physically).

ReadyNas Duo v2 show SMART status

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