UBI error: ubi_create_volume: cannot create volume 1, error -28

平台：AT91SAM9G25EK
整个nand mtd分区分了3部分分别为mtd0 mtd1 mtd2

mtd0	存放kernel uboot bstrap
mtd1	ubifs ubi volume 1
mtd2	ubi volume 1

[    2.489000] UBI: attaching mtd2 to ubi1
[    2.493000] UBI: physical eraseblock size:   131072 bytes (128 KiB)
[    2.499000] UBI: logical eraseblock size:    126976 bytes
[    2.504000] UBI: smallest flash I/O unit:    2048
[    2.509000] UBI: VID header offset:          2048 (aligned 2048)
[    2.515000] UBI: data offset:                4096
[    2.786000] UBI: max. sequence number:       34
[    2.806000] UBI: attached mtd2 to ubi1
[    2.809000] UBI: MTD device name:            "usrdata"
[    2.815000] UBI: MTD device size:            91 MiB
[    2.819000] UBI: number of good PEBs:        728
[    2.824000] UBI: number of bad PEBs:         0
[    2.828000] UBI: number of corrupted PEBs:   0
[    2.833000] UBI: max. allowed volumes:       128
[    2.837000] UBI: wear-leveling threshold:    4096
[    2.842000] UBI: number of internal volumes: 1
[    2.846000] UBI: number of user volumes:     1
[    2.851000] UBI: available PEBs:             56
[    2.855000] UBI: total number of reserved PEBs: 672
[    2.860000] UBI: number of PEBs reserved for bad PEB handling: 7
[    2.866000] UBI: max/mean erase counter: 2/1
[    2.870000] UBI: image sequence number:  -661745834
[    2.875000] UBI: background thread "ubi_bgt1d" started, PID 465
[    2.913000] UBI error: ubi_create_volume: cannot create volume 1, error -28
ubimkvol: UBI_IOCMKVOL: No space left on device
[    2.995000] UBIFS: mounted UBI device 1, volume 0, name "appdata"
[    3.001000] UBIFS: file system size:   82661376 bytes (80724 KiB, 78 MiB, 651 LEBs)
[    3.009000] UBIFS: journal size:       4190208 bytes (4092 KiB, 3 MiB, 33 LEBs)
[    3.016000] UBIFS: media format:       w4/r0 (latest is w4/r0)
[    3.022000] UBIFS: default compressor: lzo
[    3.026000] UBIFS: reserved for root:  3904300 bytes (3812 KiB)

文件系统挂载后,将mtd2格式化ubi volume并挂载，结果发现挂载失败，提示空间不足《ubimkvol: UBI_IOCMKVOL: No space left on device》，error=-28

挺奇怪的。因为，整个分区90M大小，啥东西没有。

df查看，mnt/data也已经挂载。原因究竟为何？？创建了一个4M大小的文件后，df显示如下，感觉挺正常的。

[root@(none) /]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
ubi0:rootfs              26836      2240     24596   8% /
devtmpfs                 62648         0     62648   0% /dev
ubi1_0                   73972      4424     65736   6% /mnt/data

从打印入手吧。

整个格式化mtd2为ubi系统类型的分区步骤有3个

首先attach 然后 make volume,最后 mount，rcS的启动脚本相关的三行命令如下

#attach mtd2 to be ubi volume
ubiattach /dev/ubi_ctrl -m 2
#make ubi1 size=80MiB dynamic
ubimkvol /dev/ubi1  -N usrdata -s 83886080 -t dynamic
#mount ubit ---> /mnt/data
mount -t ubifs ubi1_0 /mnt/data

对打印信息提示的错误来说，问题出现在第二步ubimkvol上，下面截取上面打印的一部分进行分析

[    2.809000] UBI: MTD device name:            "usrdata"	//是准备创建一个命名为usrdata的ubi vol，没错！！
[    2.815000] UBI: MTD device size:            91 MiB	//隶属的mtd分区大小 没错
[    2.819000] UBI: number of good PEBs:        728 //728 ÷ 8 = 91MiB 没错
[    2.824000] UBI: number of bad PEBs:         0 //没坏块 差不多
[    2.828000] UBI: number of corrupted PEBs:   0//掉电 数据损坏的块，没有，正常
[    2.833000] UBI: max. allowed volumes:       128//最大允许的vol数量
[    2.837000] UBI: wear-leveling threshold:    4096//损耗阀值
[    2.842000] UBI: number of internal volumes: 1//
[    2.846000] UBI: number of user volumes:     1
[    2.851000] UBI: available PEBs:             56//该mtd只能获取56个，什么情况！！！！？？？明明该分区啥玩意没有啊！
[    2.855000] UBI: total number of reserved PEBs: 672//保留了672

问题很明显，出在PEB的数量为什么只有56个可用？？

重新reboot在uboot里用nand erase 把mtd2擦除下就OK

擦除后，重新启动后的打印信息如下：

[    2.486000] UBI: attaching mtd2 to ubi1
[    2.490000] UBI: physical eraseblock size:   131072 bytes (128 KiB)
[    2.496000] UBI: logical eraseblock size:    126976 bytes
[    2.502000] UBI: smallest flash I/O unit:    2048
[    2.506000] UBI: VID header offset:          2048 (aligned 2048)
[    2.512000] UBI: data offset:                4096
[    2.650000] UBI: empty MTD device detected
[    2.654000] UBI: max. sequence number:       0
[    2.659000] UBI: create volume table (copy #1)
[    2.668000] UBI: create volume table (copy #2)
[    2.682000] UBI: attached mtd2 to ubi1
[    2.685000] UBI: MTD device name:            "usrdata"
[    2.691000] UBI: MTD device size:            91 MiB
[    2.695000] UBI: number of good PEBs:        728
[    2.700000] UBI: number of bad PEBs:         0
[    2.704000] UBI: number of corrupted PEBs:   0
[    2.709000] UBI: max. allowed volumes:       128
[    2.713000] UBI: wear-leveling threshold:    4096
[    2.718000] UBI: number of internal volumes: 1
[    2.722000] UBI: number of user volumes:     0
[    2.727000] UBI: available PEBs:             717
[    2.731000] UBI: total number of reserved PEBs: 11
[    2.736000] UBI: number of PEBs reserved for bad PEB handling: 7
[    2.742000] UBI: max/mean erase counter: 0/0
[    2.746000] UBI: image sequence number:  1705172159
[    2.751000] UBI: background thread "ubi_bgt1d" started, PID 464
[    3.248000] UBIFS: default file-system created
[    3.290000] UBIFS: mounted UBI device 1, volume 0, name "usrdata"
[    3.296000] UBIFS: file system size:   72376320 bytes (70680 KiB, 69 MiB, 570 LEBs)
[    3.304000] UBIFS: journal size:       3555328 bytes (3472 KiB, 3 MiB, 28 LEBs)
[    3.311000] UBIFS: media format:       w4/r0 (latest is w4/r0)
[    3.317000] UBIFS: default compressor: lzo
[    3.321000] UBIFS: reserved for root:  3418512 bytes (3338 KiB)