I'm testing the f2fs data compression feature. I created a new FS with the flags extra_attr and compression, use chattr -R +c on the test dir to enable compression for the directory. I found that when compression was turned on, the files did not take up any less space. Using trace, I see that the data is indeed compressed. Is there a mistake in my testing method, or is this how it was designed and why?
This is my test method: # mount /dev/nvme0n1 on /mnt type f2fs (rw,lazytime,relatime,background_gc=on,discard,no_heap,user_xattr,inline_xattr,acl,inline_data,inline_dentry,flush_merge,extent_cache,mode=adaptive,active_logs=6,alloc_mode=reuse,fsync_mode=posix,compress_algorithm=lz4,compress_log_size=2) # df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 114901 112444 0 100% / devtmpfs 497436 0 497436 0% /dev tmpfs 500060 0 500060 0% /dev/shm tmpfs 500060 52 500008 0% /tmp tmpfs 500060 20 500040 0% /run /dev/nvme0n1 10483712 499724 9983988 5% /mnt # mkdir test # chattr -R +c test/ # dd if=/dev/zero of=/mnt/test/file bs=1M count=100 # sync # df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 114901 112444 0 100% / devtmpfs 497436 0 497436 0% /dev tmpfs 500060 0 500060 0% /dev/shm tmpfs 500060 368 499692 0% /tmp tmpfs 500060 20 500040 0% /run /dev/nvme0n1 10483712 602232 9881480 6% /mnt _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
