formatting a drive to FAT32 with mkdosfs, need some info

Question

I'd like to know how I can specify the cluster size when using mkdosfs /dev/sdx -F 32. I read somewhere that if you want to format it with a 32kb cluster size, this is the command:

mkdosfs /dev/sdx -s 64 -F 32 -I

But, what if I want to format it with a 64kb cluster size? How can I do it? Can someone explain the proper usage of mkdosfs /dev/sdx -s XX in plain words (I'm not a native english speaker)?

Solution

I believe the command is:

sudo mkdosfs /dev/sdXX -s 128 -F 32 

Since you want 64KB clusters, and the -s means sectors per cluster so, you need 128 sectors, because 128*512 byes = 64KB, making a cluster.

If you want the whole disk to contain a single partition, you would use -I option. So, the command becomes,

sudo mkdosfs /dev/sdX -s 128 -F 32 -I

^{Credit goes to this Ubuntu forum thread}

Comments

[Hairo]

thanks, this was exactly the info i was looking for, i mean the sectors*bytes thing...

[Elder Geek]

Note that Windows older versions don't support 64K or larger cluster sizes so if you need cross compatibility you might not want to do this: See forensicswiki.org/wiki/FAT#FAT32

[Tcll]

I used to format 64k on WinXP for DIOS MIOS (fastest setting btw)... not sure what I did to enable the selection though... >_>

[Timo]

I have a partition with type W95 FAT32 (LBA). Do I still need mkdosfs if I want to use the default format? Maybe with fdisk I only prepare the partition to fat32 but with mkdosfs I create the filesystem.