Stefano Spinucci writes: > I just tried to use git writing to my FAT32 formatted usb stick. > > On windows XP, I compiled git with and without NO_D_TYPE_IN_DIRENT, > but after the > following actions I always got the error "fatal: Unable to write new > index file" or > "fatal: unable to create '.git/index': File exists": Compile git with NO_MMAP. The problem is that the old index file is mmaped while it is replaced. Cygwin supports this operation only on NTFS. I don't know whether this is a bug in cygwin or a windows limitation (I suspect the latter). Unfortunately NO_MMAP makes git pretty slow if the pack files get larger than about 10-20 MB. Johannes claims that there are additional problems with mmap on cygwin, but it passes the complete test suite on NTFS, so it should be ok for most operations IIRC it has been suggested on the list that mmaping the index isn't that important for git performance and it could be replaced by simply reading the index file into memory on access. It would be nice to have mmap work on non-NTFS partitions since my tests suggest that FAT32 is up to twice as fast (in the hot cache case). (My test version simply uses an unlink before the rename in lockfile.c to hack around the cygwin rename problem.) - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html