[mythtv-users] RAID 1 mirror with mythtv backend???

[Stephen Worthington]

On Sat, 26 Jan 2019 09:26:24 -0500, you wrote:

>
>On 1/25/19 6:37 PM, Will Dormann wrote:
>> On 1/24/19 12:05 AM, Stephen Worthington wrote:
>>> Those are CRC errors, and in a large quantity like that they are
>>> normally indicative of a bad SATA cable (or one that is not firmly
>>> plugged on).  Or possibly a USB cable problem in this case.  Dirty
>>> connectors will also show up like this, and having the cat tread on
>>> the cable can also do it.
>>>
>>> If the cable is OK, then the next most likely candidate for the cause
>>> is a bad SATA port.
>>
>> I concur here.   From your SMART report:
>>
>>    5 Reallocated_Sector_Ct   0x0033   100   100   005    Pre-fail
>> Always       -       0
>> 196 Reallocated_Event_Count 0x0032   100   100   000    Old_age
>> Always       -       0
>> 197 Current_Pending_Sector  0x0022   100   100   000    Old_age
>> Always       -       0
>> 198 Offline_Uncorrectable   0x0008   100   100   000    Old_age
>> Offline      -       0
>>
>> All of your raw values (the last column) are 0.   This implies that the
>> drive itself is internally fine.  Which generally leaves the SATA
>> controller and/or cable.
>>
>> Additionally from your report:
>> SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 1.5 Gb/s)
>>
>> I assume that your controller is only SATA 1.0?   If not, then that's a
>> likely sign that your cable is bad enough that the drive negotiated down
>> to a slower speed due to unreliable communications.
>>
>>
>> -WD
>
>
>The controller is part of the Sandy Bridge chipset so it's 2 SATA 6GBs 
>and 4 SATA 3GBs.  So I moved the drive in question to another test PC 
>with same controller and new Cable, the locking kind. Then ran the 
>smartctl -t long and it came out complete good.
>
>I have also replaced my cables on the 2 locations in question in my 
>production system. No issues yet there.
>
>So I'm going to leave things untouched for a month and see what happens
>
>Jim A

Drive SMART self tests do not move data off the drive to the PC, so
they do not test cable and SATA port faults.  So the drive passing a
long self test is another indicator that the drive itself is probably
OK and the problem is elsewhere.