Contents
Are there any drawbacks to using JFFS2?
But do not complain when you have noticed that the performance suffers. Owing to peculiarities of flash devices, JFFS2 is very different to conventional HDD-oriented file system. And one of its drawbacks is that mount time as well as memory consumption grow linearly with growing flash size.
Can a JFFS2 image be flash on a NAND flash?
As it does complain, there is something wrong with the data it reads. One common mistake is to use /dev/mtdX or /dev/mtdblockX devices to flash JFFS2 images on NAND flashes. E.g. This is incorrect because when dealing with NAND flashes one has to skip bad eraseblocks and write only in NAND page size chunks.
Is the JFFS2 subsystem bug-free in Linux?
Also, JFFS2 implements only write-through caching (while conventional filesystems have write-back) and does many things which are not really needed in the case of hard drives. So, beware of this and think twice. Also, nobody guarantees block2mtd is bug-free.
When to use JFFS2 as a root filesystem?
The first is when JFFS2 is used as a root filesystem. For now, this requires the mtdblock device to be specified for root= on the kernel command line. The second case is when the mount binary that is being used does not play nicely with the above format. The BusyBox version of mount is known to not work without the mtdblock device.
Can You mount a MTD device to JFFS2?
Erase your MTD device and mount it to JFFS2. You will end up with an empty file system. Copy some files to the JFFS2 file system and unmount it. Then mount it again and see if it mounts without problems. If it does, this is most probably not a JFFS2 bug. I am going to use JFFS2 on top of my hard drive, is it OK?
When to move JFFS2 message to higher log level?
JFFS2 adopts the philosophy of keeping the user completely appraised of what is going on. This can catch out the unwary novice. The following messages can be moved to a higher log level once you are sure that they are benign. This message is generated if a block of data is partially written. It is generally not a sign of any problem.