I posted this question at StackExchange. https://unix.stackexchange.com/questions/626326/why-does-ddrescue-require-preallocation-to-not-truncate-on-samba-target
Short version: Gnu ddrescue 1.22 truncates recovered files on completion to vastly shorter than the recovered data. Details: * Files are on a Samba server with more than 4 TB free. * smbclient version is 4.7.6 * smbd version is 4.11.6 * If ddrescue is invoked with -p (preallocate), the preallocation takes forever (compared to the recovery and write to file) but the resulting file is correct (not truncated). It's been some time there, with no replies. Also, every computer in the example has been rebooted since that question was posted. The bug is still present. Any ideas? This is really two bugs: truncation and glacial preallocation. -- -- Eric Towers ! fuzzye...@gmail.com