HDD - NTFS partition: Possible to reduce size of cluster allocation bitmap?



  • Many of you have probably noticed that new or freshly formatted HDDs have used space already, without you putting anything on them. The NTFS file system contains several internal files, such as a cluster allocation bitmap, log file, volume descriptor file and so forth.

    Does anyone know if it is possible to reduce the amount of space needed for this, so that we can place even more plots in there?


  • admin

    @Propagandalf said in HDD - NTFS partition: Possible to reduce size of cluster allocation bitmap?:

    cluster allocation bitmap

    Use 64KB sector size when you format - but the savings are minimal.



  • @haitch

    OK, thanks. Is that the only thing we can do to lessen the already-used space?


  • admin

    @Propagandalf to the best of my knowledge - making the sector size as large as possible minimizes the overhead.



  • @haitch I did a format with 64 KB sector size now, and I went from 540 MB used space and to 187 MB, on a 4 TB drive.



  • I only know it for Linux-systems and wouldn´t miss this option.

    If you create an ext3 or ext4 filesystem in linux, there will also be 5% of the space reserved for some OS-stuff. (similar to NTFS). With the following command (=command 1) you could reduce this value to 0% and get 5% more space out of your HDD! 🙂

    If you doing this and if you have many little Plotfiles i would also recommend you to use hashed b-trees to speed up the drive lookups. In easy words this will speed up the reading time. I not measure the effect, but in theory there should be one. (=command 2)

    With command 3 you "activate" these settings. Make sure that your drive is dismountet for that!

    1. sudo tune2fs -m 0 /dev/sdxY 
    2. sudo tune2fs -O dir_index /dev/sdXY 
    3. sudo e2fsck -fD /dev/sdXY
    

    BUT: Do this only, if your HDD is not running your OS and you use it only for Mining!

    If i should explain it a little more in Detail feel free to ask or look at the tune2fs manpage (https://linux.die.net/man/8/tune2fs)

    EDIT:
    Some additional Information: If you creating your new Ext4- or Ext3- Filesystem for your plotfiles, i would recommend to use big Clusters with the "-T" option. You could only do this when you create the Filesystem and couldn´t change it afterwards. Here is an example

    sudo mkfs.ext4 -m 0 -T largefile4 -L Partition_Name /dev/sd...