2017-09-20 11:59 GMT+03:00 shally verma <shallyvermacav...@gmail.com>: > On Wed, Sep 20, 2017 at 2:25 PM, Timofey Titovets <nefelim...@gmail.com> > wrote: >> 2017-09-20 11:44 GMT+03:00 shally verma <shallyvermacav...@gmail.com>: >>> One more catch... I am initiating fio from non-btrfs filesystem i.e. >>> pwd is ext4 based fs where as mount point is btrfs. >>> Could that make difference? >>> >>>> Thanks >>>> Shally >> >> Only matter are where you store test file =) >> If you store test file on btrfs, pwd does nothing. >> > > Then steps listed in previous mail should work right? Am listing them > again here: > > " ---- >> >> 1. mount -t btrfs -o compress-force=zlib /dev/sdb1 mnt >> >> 2. fio --directory=mnt/ --numjobs=1 --direct=0 --buffered=1 --bs=64k >> --rw=write --iodepth=128 --name=test --size=1G >> --buffer_compress_percentage=100 --buffer_pattern=0xFF --refill_buffer >> --ioengine=libaio >> >> 1GN file written uncompressed. Here no compression invoked (though >> compress-force=zlib) >> >> 3. cp mnt/test ./ --> copy back fio generated test file from btrfs >> mount point to local drive >> >> 4. hex dump test file (all FFs) -- confirmed that data is compressible >> no random data. >> >> 5. cp test mnt/ --> now, copy same test again back to mount point >> (reverse of step 3) . Now, here I see during copying compression is >> invoked. >> >> I am using kernel 4.9 and compress-foce is said to be working for >> kernel > 2.13 from wiki ... so I wonder what's so special with cp >> command which is not happening during fio writes??? > > "----- > > Thanks > Shally > > >> -- >> Have a nice day, >> Timofey.
I did try reproduce your problem on 4.14, i'm hard to explain that happens and why file created by FIO will not use compression. Suggest workaround: rm -v /mnt/test.0.0 dd if=/dev/zero of=/mnt/test.0.0 bs=1M count=1024 fio --directory=$HOME/test/ --numjobs=1 --direct=1 --buffered=0 --bs=64k --rw=write --iodepth=128 --name=test --size=1G --buffer_compress_percentage=100 --buffer_pattern=0xFF --refill_buffer --ioengine=libaio You can check if data compressed by filefrag -v /mnt/test.0.0 (you will see encoded extents) -- Have a nice day, Timofey. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
