Sean McCauliff wrote: > Is there a way to find the holes in sparse files, other than assuming > contiguous blocks of zeroes are holes? yes, programatically you can use a couple ioctls: fibmap (block-at-a-time) or fiemap in newer kernels. If you want a commandline, try filefrag -v. For ioctl usage examples, take a look at how filefrag is implemented. # dd if=/dev/zero of=testfile bs=4k count=1; dd if=/dev/zero of=testfile conv=notrunc bs=4k seek=4 count=1 # sync # filefrag -v testfile Filesystem type is: ef53 File size of testfile is 20480 (5 blocks, blocksize 4096) ext logical physical expected length flags 0 0 1829913 1 1 4 1802777 1829913 1 eof testfile: 2 extents found the logical+length gap shows you that there was a hole in there Andreas has patches to make it still clearer in the table output. -Eric > Thanks, > Sean > > _______________________________________________ > Ext3-users mailing list > Ext3-users@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/ext3-users _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
