i added 2x 3TB drives to my array, took the old 2TB parity and changed it to a data drive. The only drive that has any data on it is my other 2TB drive so i sacrificed parity and did a new disk config as follows.

 

i assigned one 3TB drive to parity, the other to disk1 and the two 2TB drives as disk2 and disk3 (after hitting new config button of course). Started the array, formatted the new 3TB drive and old 2TB parity drive, and stated parity calc. Sync was humming along nicely at 90+MB/sec at the start sometimes over 100MB/sec. great.

 

At about 60% through parity calc disk1 went bat crazy and dropped from the array totally, causing my syslog to fill and the system to become almost unresponsive. Traced this to a bad slot in my cage (either mobo port, slot itself or cable, but will figure that out later). Put the drive in another slot and its working as expected upon boot.

 

i re-started the now failed parity calc, but this time it started at 40MB/sec, almost half the speed.

 

some farting around later and I swapped the 3TB drives between parity and disk1 and started new parity calc. Speed was back to 90ishMB/sec.

 

Currently at 30% and 78MB/sec which is what i would expect as it get closer to 100%.

 

something definitely not right with this though.

 

well the sync is still going.. this is not normal. my 2TB check/sync only ever took 9-10hrs this is at hour #17 and still has 200 minutes to go.

 

current sync speed is 5-10MB/sec. Obviously something's up.

Attach a syslog and SMART reports.

syslog. working on smarts reports.

 

both 3TB drives pre-cleared a'ok in similar amount of times with 0 sectors re-allocated either before, during, or after as well.

syslog-2012-08-22.txt

smart reports for the two 3TB drives.

smart_report_1.txt

smart_report_2.txt

also the sync completed with 0 errors.

 

took 22 hours (79,013 seconds per syslog).

 

for 3TB thats an average of about 37MB/sec, pitiful really.

 

going out of town tomorrow for two days.. considering starting a parity check (no correct) before I leave...

screen shot of 'Main'

 

started parity check just now.

 

started at 40-50MB/sec. crept up to 80MB/sec and stabilized there.

 

changed the md_sync_window setting to 512 from default and restarted the check.

 

immediately started at 105MB/sec and is currently at 109MB/sec.

 

now to see where it is when it ends....

parity check completed in 37,732 seconds, or 10ish hours. less than half the time of the parity calc.

 

average 79MB/sec no correct check.

 

found 0 errors.