Yes that's the way. Pickup 64 MB. You can lower it or disable it or even keep it after tar is over successfully.

While you are at it, use the partition type as 'b' instead of '6' for /dev/mmcblk0p1

Use
Code:

# apt-get install e2fsprogs
# umount /media/mmc1
# umount /media/mmc2 (for N800 only!)
# sfdisk /dev/mmcblk0
/dev/mmcblk0p1:1,52500,b
/dev/mmcblk0p2:52501,,
/dev/mmcblk0p3:
/dev/mmcblk0p4:

That will make mmc1 partition as FAT32 instead of FAT16. Believe me you will realise its imprtance later. ALSO NOTE: that the above numbers are for 2 GB ard. The 52500 will put about 1.68 GB in MMC1 and 320 MB in mmc2 which is for dual boot partition on your mmc.