[maemo-developers] Best format for SD ?

[From: Andrew Daviel]

By default, SD cards come preformatted as VFAT, as does the internal SD 
on the N810. If you want to mount them on Windows, they have to stay that 
way. But you can also reformat them with a Linux file system, or create 
multiple partitions.

One problem with leaving the card as VFAT is that you cannot create 
symlinks from the root filesystem. Also VFAT does not support 
attributes such as ownership or execute bits. The default mount is
/dev/mmcblk0p1  /media/mmc1 vfat rw,noauto,nodev,noexec,nosuid,utf8,uid=29999 0 0
i.e. belonging to "user" and you can't execute programs.

The kernel on the N810 (OS2008) supports ext2 and ext3 file systems. I 
just  reformatted both my internal and removable SDs as ext3 (also 
created a swap partition on /dev/mmcblk1p2) and it seems to work as far 
as I can see.

What is the best available F/S for flash ? And what options ?
I have set noatime as Nokia has on / (don't write the access time)

I saw an interesting webcast by Mentor Graphics where they were talking 
about designing a new filesystem especially for flash, which would be
100% fault tolerant to loss of power and would minimize write cycles etc.
They mentioned problems with FAT as not being fault tolerant and not 
supporting large files. Also that flash may have a limited number of 
write cycles per bit (around a hundred). (so maybe I should use ext2 not 
ext3 to minimize journal writes, or put the journal on / (whataver 
technology that is... it's mounted jffs2.)

-- 
Andrew Daviel, TRIUMF, Canada
Tel. +1 (604) 222-7376  (Pacific Time)
Network Security Manager