126 reputation
4
bio website
location
age
visits member for 1 year, 11 months
seen Aug 28 at 15:04

Apr
16
comment RabbitMQ Management console not working
Having exactly the same problem.
Dec
3
awarded  Scholar
Dec
3
accepted Windows Server 2008 Software Raid 5 - Data integrity issues
Dec
3
comment Windows Server 2008 Software Raid 5 - Data integrity issues
After extensive memtesting and running full surface scans on every disk in the array (without incident), I was able to borrow a replacement SATA card from a coworker. Swapping the card out appears to have eliminated the problem - so I must conclude that my disk controller was to blame. I really can't imagine a more insidious problem - unreported write errors so sparse that it took me months to notice. Nevertheless, I'm glad to have the issue isolated. I'm now beginning the process of rebuilding the array from the last good backup. Thank you for your assistance.
Nov
27
awarded  Editor
Nov
27
revised Windows Server 2008 Software Raid 5 - Data integrity issues
added 242 characters in body
Nov
27
comment Windows Server 2008 Software Raid 5 - Data integrity issues
I haven't had time to do the one-stick of ram at a time test, but I did write myself a little tool to do a binary-diff of giant files. What I've found after testing multiple corrupt copies of a 20gb file is that the corrupted data always appears in chunks of 60 contiguous bytes. The damaged data appears to be total garbage, there isn't any discernible pattern to which bits are being flipped. Comparing two corrupt 60-byte chunks to one another, the pattern of flips did not match. Still can't rule out system memory, but now I know for sure these are not single bit flips.
Nov
26
comment Windows Server 2008 Software Raid 5 - Data integrity issues
Thanks for your thorough reply. The corrupted files always reproduce the same "wrong" hash once they have been written, so we can eliminate #4. I tried copying about 25 GB worth of smaller (~800MB) files, and found that all of those copied correctly - this makes me think system ram may be the culprit after all, despite a few successful passes in memtest. My plan tonight is to run the system with only one stick of ram at a time, and repeat my hash-copy-hash check of a large file a dozen times each. Since the problem is easily reproducible currently, this should help me narrow it down.
Nov
26
awarded  Supporter
Nov
25
awarded  Student
Nov
25
asked Windows Server 2008 Software Raid 5 - Data integrity issues