CRC Checksum missmatch transfering large files to NAS

network-attached-storagenetworkingqnapwindows-server-2008-r2

I'm having a problem transfering large (50-200GB) VHD files from a Windows Server 2008R2 machine to a QNAP NAS. After the transfer is completed, I verify the data using a CRC32 checksum to ensure it wasn't corrupted (these are important backups). I am getting constant CRC miss-matches for large files. I have tried using SAMBA and FTP, both with the same problem. I have tried several different tools to calculate the CRC checksum to rule out false negatives.

This is what I've tried so far:

  • Different Windows server (no fix).
  • Different NIC/Cables/Switches (no fix).
  • Different Updating NAS firmware (no fix).
  • Different destination server (I built a samba server in ubuntu which worked fine).
  • The same process works in another office with an identical model NAS using SMB.

IMO, this has been narrowed down to the QNAP device. I've ruled out the windows server, networking gear, samba protocol/version. Is there anything else I could try?

The QNAP share is configured as a RAID5 with the EXT3 filesystem.

Best Answer

Problem Solved.

It turns out to have been caused by a Faulty Western Digital SATA Hard Drive. We ended up replacing it and the problem went away (even though it passed all the drive tests).

WD drives have been nothing but trouble here. Thanks for the responses.