When configuring user disk quotas I need to find out the block size on my SCSI hard disk drive. For example if I am using a block size of 1024 then setting block size to 102400 blocks limit my user to 100MB of disk space.
Therefore, it is necessary to determine the correct block size; otherwise, I will end up assigning wrong disk quota limit.
You can use dumpe2fs command, which prints the super block and blocks group information for the filesystem present on device. You need to type dumpe2fs command as the root user:
# dumpe2fs /dev/sdb3 | grep -i 'Block size'
Block size: 4096
Now setting a user quota of 40960 would limit a user to 10MB of disk space.
Please note that dumpe2fs command used to determine the actual size of a block on the filesystem (and not BLOCK SIZE OF FILESYSTEM not harddisk).