Before getting into the output here is my typical experience with SMART, there is what I call a "bad disk" with pending and uncorrectable sectors that cannot be reallocated.
It has caused a kernel panic and system crash repeatedly as we can see from the logs.
But SMART says it has "PASSED" its self assessment. SMART is still useful to me but it is more about looking at Current_Pending_Sector.
Any time I have had anything but 0 for that attribute it........
This is just trying to read 5GB off the drive with dd and the drive initially tested ok but shortly after I wondered why I was seeing 2MB/s read speeds. Notice the "current_pending_sector", anytime I've seen it at anything above 0 even with no other bad fields/attributes, it means the drive is bad.
ata1.00: exception Emask 0x0 SAct 0x3 SErr 0x0 action 0x0
ata1.00: irq_stat 0x40000008
ata1.00: failed command: READ FPDMA QUEUED
ata1.00: cmd 60/00:00:........
I like dd, although it only reads it, usually a read test of the entire disk will uncover if your hard drive is bad in some parts. This is a good thing to do at least once a month, a lot of times bizarre program behavior, laginess and crashing/unnmounting problems etc.. are due to a failing disc and SMART won't know it or indicate a problem:
We must also remember there's never a guarantee, I've found that ever since we moved to larger and more platters per drive with 1TB drives........
I had a dying drive that smart thought until it totally disappeared was a good drive, and actually all parameters did look fine but this system was causing my system to lockup and other bad behavior:
=== START OF INFORMATION SECTION ===
Device Model: WDC WD20EARS-00MVWB0
Serial Number: WD-WMAZ20139
Firmware Version: 50.0AB50
User Capacity: 2,000,398,934,016 bytes
Let the numbers speak for themselves, from what I read the Load_Cycle_Count which is very high (more than 500,000/half a million times) is the number of head parks. What a stupid"Green" design and design flaw which will probably mean an early life for the drive.
This is almost as silly as Seagate's new reputation for BSY/poor quality disks since the 7200.11 series.
To make it worse this is also when Western Digital introduced "Advanced Format" o........