On Dec 6 10:38, Corinna Vinschen via Cygwin wrote: > Again, the filesystem doesn't matter. It either sets the > FILE_SUPPORTS_SPARSE_FILES flag or not, as simple as that. > > If it does, you can create sparse files with chattr +S, or you can rely > on the lseek/ftruncate/posix_fallocate automatism, or you stamp a hole > into the file with fallocate(FALLOC_FL_PUNCH_HOLE). > > The *only* difference is if you have to use the "sparse" mount option or > not. > > Basically, with 3.4, you always have to set the "sparse" mount option, > with 3.5, on local SSDs you don't. I don't see a problem here.
Oh, and to be very clear here: This *only* affects new files or files which are not yet sparse. As soon as a file is sparse, it stays sparse. Subsequently, the way sparse blocks are created or converted to allocated blocks during write, lseek, ftruncate/posix_fallocate depends solely on how the OS and the filesystem driver perform in this matter. Cygwin is out of the picture then. After all, it's still just a user space DLL. Corinna -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
