[SOLVED] [Ubifs] "vtbl_check: too large reserved_pebs"

Hello

I went through the docs/FAQs on the MTD/UBI site and elsewhere, and proceeded to create a Ubifs root filesystem and flash a NAND partition with it.
However, "ubiattach" fails, so I guess I didn't use the right settings in mkfs.ubifs and/or ubinize and/or ubiformat for use with that NAND partition.

Here are the steps I took.

First, get infos about NAND

appliance:/> mtdinfo /dev/mtd2 -u
mtd2
Name:                           filesystem_nand
Type:                           nand
Eraseblock size:                131072 bytes, 128.0 KiB
Amount of eraseblocks:          1984 (260046848 bytes, 248.0 MiB)
Minimum input/output unit size: 2048 bytes
Sub-page size:                  512 bytes
OOB size:                       64 bytes
Character device major/minor:   90:4
Bad blocks are allowed:         true
Device is writable:             true
Default UBI VID header offset:  512
Default UBI data offset:        2048
Default UBI LEB size:           129024 bytes, 126.0 KiB
Maximum UBI volumes count:      128

Next, cCreate root filesystem

ubuntu:/> mkfs.ubifs --squash-uids -m 2048 -e 131072 -c 1984 -d
./romfs -D device_table-min.txt -o ./images/rootfs.ubifs

Ubinize image

ubuntu:/> cat ubi.cfg
[ubifs]
mode=ubi
image=./images/rootfs.ubifs
vol_id=0
vol_size=248MiB
vol_type=dynamic
vol_name=rootfs
vol_flags=autoresize

ubuntu:/> ubinize -o rootfs.ubi.img -m 2048 -p 128KiB -s 512 ./ubi.cfg

On the appliance, format the partition on the NAND memory:

appliance:/> ubiformat /dev/mtd2 -s 512 -f rootfs.ubi.img

Finally, attach the MTD partition to Ubi before mounting it:

appliance:/> ubiattach /dev/ubi_ctrl -m 2
UBI: attaching mtd2 to ubi0
UBI: physical eraseblock size:   131072 bytes (128 KiB)
UBI: logical eraseblock size:    129024 bytes
UBI: smallest flash I/O unit:    2048
UBI: sub-page size:              512
UBI: VID header offset:          512 (aligned 512)
UBI: data offset:                2048
UBI error: vtbl_check: too large reserved_pebs 2016, good PEBs 1984
UBI error: vtbl_check: volume table check failed: record 0, error 9
UBI error: ubi_attach_mtd_dev: failed to attach by scanning, error -22
ubiattach: error!: cannot attach mtd2
           error 22 (Invalid argument)

I assume I used one or more settings wrong, but I don't know which. Maybe I must leave some room for the journal + recovery data?

Thank you.

In case someone has the same problem... the solution is to...

1. Edit the Makefile that runs mkfs.ubifs so that it uses the right setting for the "-e" option, which is computed by this formula:
   
   LEB_size = PEB_size - ((Subpage_size + Page_size)) / Page_size) * Page_size
   (In the division, keep the integer part)
   
   Also make sure you use the right setting for "-c" ("Amount of eraseblocks")
2. In ubi.cfg, make sure you use a "vol_size" that's smaller than the actual size of the partition on the NAND to leave room for Ubifs internal data. With "vol_type=dynamic", Ubifs will end up using the whole space automatically