STINNER Victor <vstin...@redhat.com> added the comment:
I'm curious: is it possible to query the filesystem to check if a copied is copied using CoW? I guess that it's possible, it will be non portable. So I guess that it's better to avoid checking that in unit tests. vstinner@apu$ dd if=/dev/urandom of=urandom bs=1k count=1k 1024+0 records in 1024+0 records out 1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.0309671 s, 33.9 MB/s vstinner@apu$ cp --reflink urandom urandom2 'urandom' -> 'urandom2' vstinner@apu$ stat urandom File: urandom Size: 1048576 Blocks: 2048 IO Block: 4096 regular file Device: 31h/49d Inode: 16265363 Links: 1 Access: (0664/-rw-rw-r--) Uid: ( 1000/vstinner) Gid: ( 1000/vstinner) Context: unconfined_u:object_r:user_home_t:s0 Access: 2019-06-05 13:56:21.381196972 +0200 Modify: 2019-06-05 13:56:21.412197007 +0200 Change: 2019-06-05 13:56:21.412197007 +0200 Birth: 2019-06-05 13:56:21.381196972 +0200 vstinner@apu$ stat urandom2 File: urandom2 Size: 1048576 Blocks: 2048 IO Block: 4096 regular file Device: 31h/49d Inode: 16265364 Links: 1 Access: (0664/-rw-rw-r--) Uid: ( 1000/vstinner) Gid: ( 1000/vstinner) Context: unconfined_u:object_r:user_home_t:s0 Access: 2019-06-05 13:56:24.487200453 +0200 Modify: 2019-06-05 13:56:24.496200463 +0200 Change: 2019-06-05 13:56:24.496200463 +0200 Birth: 2019-06-05 13:56:24.487200453 +0200 Using stat command line tool, I don't see anything obvious saying that the two files share the same data on disk. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue37157> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
