I'm in the process of moving stuff from our Alpha fileserver onto A linux replacement. I've been using gnu-tar to copy filesystems from the Alpha to to the Linux NFS-exported disks over a 1Gbit LAN, followed by diff -r to check that they have copied correctly (I wish diff had an option to not follow symlinks..). I've so far transferred about 3 TiB of data (spread over several weeks) and am concerned that during this process, 3 files were mis-copied without any apparent hardware-errors being flagged. There was nothing unusual about these files, and re-copying them (with cp) fixed the problem. Are occasional undetected errors like this to be expected? I thought there were sufficient stages of checksumming/parity (both boxes have ECC memory) etc to render the probability of this to be vanishingly small. On all 3 files, multiple retries of the diff still resulted in a compare error, which was then fixed by a re-copy. This suggests that the problem occurs during the 'gtar' phase, rather than the 'diff -r' phase. Does anyone know of a network-exercise utility I can use to check the LAN component of the data-path? Cheers, Terry.
