How much data loss do these 3ware 9650SE errors represent ?

[John Case]

I know 3ware 9650SE cards are a bit old, but a lot of people still have 
and use them ...

I have an 8 drive, raid6 array that lost one drive, then another died 
during rebuild, and then a third drive created some errors.

So, I set the card to ignoreECC during rebuild ...

Things went well and the array is rebuilt and healthy, BUT I got 21 of 
these errors:


c0 [date] ERROR Source drive ECC error overwritten: port=4


So I have data loss in 21 places in the array.

But how much ?

I cannot find any documentation of the size of this data loss - does each 
error message represent a secor ? a block ?  I know it doesn't represent 
"files" or "directories" since the raid card doesn't know anything about 
the UFS2 filesystem running on it.

Does anyone have any idea how much data each of these errors represents ?

Thanks.