Increase in 1GB+ DLs Failing to Unpack Due to CRC Error

[jasoncole2003]

I am using v0.7.16 running on WHS2011(64-bit) and I have noticed an increase lately in unpacking failures on files exceeding 1GB in size. The download completes, the quick check returns OK, and then the unpack fails with a CRC error. Reviewing the log files it appears that Sabnzbd runs the Quick Check which returns a status of "OK, no repair needed", Sabnzbd then deletes the .par2 file(s), begins the extraction process, and then fails with the CRC error.

I realize that in most cases a CRC error reported indicates a loss of fidelity in the copy of the data and so this wouldn't typically point to a Sabnzbd issue but rather a copying (download) or storage problem. However, the quick check utility doesn't report any damage, Sabnzbd deletes the .par2 file(s) since the archive isn't reported as damaged, and WinRAR's archive integrity check reports no issue with the archive or any of the individual files. After Sabnzbd reports the CRC error if I access the Incomplete folder directly and open the archive in WinRAR I can successfully extract the files without any problem or error, CRC or otherwise. The Sabnzbd download folders are stored on a logical volume that spans 8x3TB drives organized in RAID 0 that is controlled by a 8 port RAID controller card. All of the drives are less than 12 months old and I am not using compression, encryption, or any enhanced functionality on the volume or drives, even Shadow Copy and VSS is disabled. Neither the RAID Controller, nor the SMART reporting on the individual drives report any issues.

Since the only application reporting that there is a CRC error is Sabnzbd and thus far this has only occurred with archives 1GB+ in size I suspect that this may be a bug or issue with Sabnzbd, rather than an actual problem with either the download process or the storage onto the local disk. Here are the log files relevant to the unpacking process, I have partially sanitized the beginning of the name of the file being downloaded but have left all other information intact:

2014-03-01 06:05:56,742::INFO::[postproc:278] Starting PostProcessing on ################### 720p HDTV x264 DHD => Repair:True, Unpack:True, Delete:True, Script:None, Cat:*
2014-03-01 06:05:57,256::INFO::[postproc:548] Par2 check starting on ################### 720p HDTV x264 DHD
2014-03-01 06:05:57,256::INFO::[__init__:859] E:\multimedia\Staging\incomplete\################### 720p HDTV x264 DHD\__ADMIN__\__verified__ missing
2014-03-01 06:05:57,256::INFO::[postproc:569] Running repair on set ###################.720p-dhd
2014-03-01 06:05:57,256::INFO::[newsunpack:826] Quick-check for ###################.720p-dhd is OK, skipping repair
2014-03-01 06:05:57,256::INFO::[newsunpack:888] Deleting E:\multimedia\Staging\incomplete\################### 720p HDTV x264 DHD\###################.720p-dhd.par2
2014-03-01 06:05:57,256::INFO::[postproc:596] Par2 check finished on ################### 720p HDTV x264 DHD
2014-03-01 06:05:57,256::INFO::[misc:788] Creating directories: E:\multimedia\Staging\complete\################### 720p HDTV x264 DHD
2014-03-01 06:05:57,272::INFO::[postproc:340] Running unpack_magic on ################### 720p HDTV x264 DHD
2014-03-01 06:05:57,272::INFO::[newsunpack:208] Unrar starting on E:\multimedia\Staging\incomplete\################### 720p HDTV x264 DHD
2014-03-01 06:05:57,272::INFO::[newsunpack:424] Extracting rarfile E:\multimedia\Staging\incomplete\################### 720p HDTV x264 DHD\###################.720p-dhd.rar (belonging to ###################.720p-dhd) to E:\multimedia\Staging\complete\_UNPACK_################### 720p HDTV x264 DHD
2014-03-01 06:06:01,469::WARNING::[newsunpack:612] ERROR: CRC failed in "###################.720p-dhd"
2014-03-01 06:06:01,484::INFO::[newsunpack:212] Unrar finished on E:\multimedia\Staging\incomplete\################### 720p HDTV x264 DHD

Please let me know if you need any other files or if there is any troubleshooting I could do to assist with further isolating the source of the issue.

[shypike]

The only tool that reports CRC errors, is unrar itself.
SABnzbd just passes the message.
It could be a problem in unrar.
Try to unpack the files on the device itself using the installed unrar.
Check it's version, try to upgrade it.