Is there a way if on a stock unraid environment to just get the Mean Time Before Fail (MTBF) via SMART disk report on a stock standard unraid server? I've been reading about this and it is quite a useful information to know indicating when your disk(s) are due to their life expectancy and giving you a hint on when it should be replaced.

 

MTBF isnt a SMART attribute but a statistical value provided by manufacturers (not just HDD manufacturers). There are a couple of others too ARR (Annual Replacement Rate) and MTTF (Mean Time To Failure). 

 

There are a couple of very good papers written a couple of years ago by google and the US army via the DoE. Both linked from this eweek article.

 

http://www.eweek.com/c/a/Data-Storage/Hard-Disk-MTBF-Flap-or-Farce/

http://db.usenix.org/events/fast07/tech/schroeder/schroeder_html/index.html

http://static.googleusercontent.com/external_content/untrusted_dlcp/labs.google.com/en//papers/disk_failures.pdf

 

They caused quite a stir back then, however we still have the same old SMART system and MTBF failure rates.

 

With regard to SMART attributes that are usefull and meaningful here is my hit list and what they mean to me...

 

Uncorrectable Sector Count (Offline_Uncorrectable) - # bad sectors

Current Pending Sector Count - # potentially bad sectors

Reallocation Event Count - # times sector reallocation was attempted

Reallocated Sectors Count - # bad sectors mapped out

 

I expect these values to be zero. Non zero values means I'm going to start paying close attention to that drive, increasing counts mean its time to find a replacement.

 

UltraDMA CRC Error Count - interface or cable errors

 

The bottom one generally means cabling issues, replace cables if you see these consistently. Always cut up suspect cables to stop someone else or you recycling them at a later date, same goes for network cables, AV cables.

Thanks Kaygee, though how are you monitoring your disks or SMART reports on your unraid server? Is it via unMENU or an addon that you'd manually installed and configured? Thanks.

I personally use unMENU (cheers BJP999/Joe L and anyone else out these who contributed) however hdparm and smartctl are both easily driven via the command line or scripts.

No worries Kaygee, thanks for the info.