On Mon, 9 Feb 2015 20:42:56 +0500 Roman Mamedov <rm@xxxxxxxxxxx> wrote: > On Mon, 09 Feb 2015 10:26:33 -0500 > "Devon B." <devon.b@xxxxxxxxxxxxxxxxxxx> wrote: > > > If you don't mind me asking, what version kernel are you running and are > > you using any special mount options? > > Well actually I did not claim I have working discard through 'loop', but your > post made me curious. > > $ sudo dd if=/dev/zero of=100g bs=1M seek=100000 count=1 > 1+0 records in > 1+0 records out > 1048576 bytes (1.0 MB) copied, 0.00221052 s, 474 MB/s > > $ sudo mkfs.ext4 100g > [...] > > $ du -hsc 100g > 133M 100g > 133M total > > $ sudo mount -o loop 100g /mnt/tmp1/ > > (then in a new terminal window): > $ cd /mnt/tmp1/ > $ df -h . > Filesystem Size Used Avail Use% Mounted on > /dev/loop0 96G 60M 92G 1% /mnt/tmp1 > $ sudo dd if=/dev/zero of=zerofile bs=1M count=1024 > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 0.944377 s, 1.1 GB/s > $ sync > > (back to the original one): > $ du -hsc 100g > 1.2G 100g > 1.2G total > (2nd window): Forgot to add I also did 'rm zerofile' here, of course. > $ sudo fstrim . > > (back to the original one): > $ du -hsc 100g > 133M 100g > 133M total > > So it does work for me just fine even with 'loop'. > Kernel version 3.14.32, mount options > rw,noatime,nodiratime,compress=zlib,space_cache,inode_cache. > -- With respect, Roman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
