はじめに
Wi-FiルータにOpenWrtをインストールしても、ROM領域が少ないのでいろいろパッケージをインストールできません。そこでUSBメモリを使いrootfsを拡張してみました。
今回はUSBメモリ全体をrootfsにしています。
参考：
- OpwnWrt - Extroot configuration
- Zopfcode - 【前編】ルーターのrootfsを拡張してPythonをビルドする
必要なパッケージをインストールします
root@GL-AR150:~# cat /etc/openwrt_release
DISTRIB_ID='LEDE'
DISTRIB_RELEASE='17.01.4'
DISTRIB_REVISION='r3560-79f57e422d'
DISTRIB_CODENAME='reboot'
DISTRIB_TARGET='ar71xx/generic'
DISTRIB_ARCH='mips_24kc'
DISTRIB_DESCRIPTION='LEDE Reboot 17.01.4 r3560-79f57e422d'
DISTRIB_TAINTS='busybox override'
root@GL-AR150:~# opkg update
root@GL-AR150:~# opkg install kmod-usb-storage
root@GL-AR150:~# opkg install usbutils
root@GL-AR150:~# opkg install gdisk
root@GL-AR150:~# opkg install block-mount
root@GL-AR150:~# opkg install e2fsprogs
root@GL-AR150:~# opkg install kmod-fs-ext4
root@GL-AR150:~# reboot
USBメモリ(/dev/sda)をフォーマットし、システム起動時に自動マウント(/mnt/sda1)されるようにします
root@GL-AR150:~# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 8192 8192 0 100% /rom
tmpfs 30088 260 29828 1% tmp
/dev/mtdblock5 6400 5312 1088 83% /overlay
overlayfs:/overlay 6400 5312 1088 83% /
tmpfs 512 0 512 0% /dev
root@GL-AR150:~# lsusb -t
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-platform/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Mass Storage, Driver=usb-storage, 480M
root@GL-AR150:~# ls -l /dev/sd*
brw------- 1 root root 8, 0 Jan 1 1970 /dev/sda
brw------- 1 root root 8, 1 Jan 1 1970 /dev/sda1
root@GL-AR150:~# gdisk /dev/sda
GPT fdisk (gdisk) version 1.0.1
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Command (? for help): p
Disk /dev/sda: 15633408 sectors, 7.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 6478B437-EECD-AA48-A2EC-56C50B396DFD
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 15633374
Partitions will be aligned on 2048-sector boundaries
Total free space is 15633341 sectors (7.5 GiB)
Number Start (sector) End (sector) Size Code Name
Command (? for help): n
Partition number (1-128, default 1):
First sector (34-15633374, default = 2048) or {+-}size{KMGTP}:
Last sector (2048-15633374, default = 15633374) or {+-}size{KMGTP}:
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'
Command (? for help): p
Disk /dev/sda: 15633408 sectors, 7.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 6478B437-EECD-AA48-A2EC-56C50B396DFD
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 15633374
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
Number Start (sector) End (sector) Size Code Name
1 2048 15633374 7.5 GiB 8300 Linux filesystem
Command (? for help): w
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): Y
OK; writing new GUID partition table (GPT) to /dev/sda.
The operation has completed successfully.
root@GL-AR150:~# mkfs.ext4 /dev/sda1
root@GL-AR150:~# block info | grep "/dev/sd"
/dev/sda1: UUID="ad3607ef-35a3-43dd-b014-8deca070c780" VERSION="1.0" TYPE="ext4"
root@GL-AR150:~# block detect > /etc/config/fstab
root@GL-AR150:~# uci set fstab.@mount[0].enabled='1'
root@GL-AR150:~# uci commit
root@GL-AR150:~# reboot
root@GL-AR150:~# uci show fstab
fstab.@global[0]=global
fstab.@global[0].anon_swap='0'
fstab.@global[0].anon_mount='0'
fstab.@global[0].auto_swap='1'
fstab.@global[0].auto_mount='1'
fstab.@global[0].delay_root='5'
fstab.@global[0].check_fs='0'
fstab.@mount[0]=mount
fstab.@mount[0].target='/mnt/sda1'
fstab.@mount[0].uuid='ad3607ef-35a3-43dd-b014-8deca070c780'
fstab.@mount[0].enabled='1'
root@GL-AR150:~# block info
/dev/mtdblock4: UUID="93bc83d3-4b85b167-6f217cd4-25ceb869" VERSION="4.0" MOUNT="/rom" TYPE="squashfs"
/dev/mtdblock5: MOUNT="/overlay" TYPE="jffs2"
/dev/sda1: UUID="ad3607ef-35a3-43dd-b014-8deca070c780" VERSION="1.0" MOUNT="/mnt/sda1" TYPE="ext4"
root@GL-AR150:~# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 8192 8192 0 100% /rom
tmpfs 30088 260 29828 1% /tmp
/dev/mtdblock5 6400 5312 1088 83% /overlay
overlayfs:/overlay 6400 5312 1088 83% /
tmpfs 512 0 512 0% /dev
/dev/sda1 7627412 34368 7185880 0% /mnt/sda1
現在のrootfs(/overlay)をUSBメモリ(/mnt/sda1)にコピーし、USBメモリをrootfsに切り替えます
root@GL-AR150:~# tar -C /overlay -cvf - . | tar -C /mnt/sda1 -xf -
root@GL-AR150:~# block detect > /etc/config/fstab
root@GL-AR150:~# sed -i s/option$'\t'enabled$'\t'\'0\'/option$'\t'enabled$'\t'\'1\'/ /etc/config/fstab
root@GL-AR150:~# sed -i s#/mnt/sda1#/overlay# /etc/config/fstab
root@GL-AR150:~# cat /etc/config/fstab
config 'global'
option anon_swap '0'
option anon_mount '0'
option auto_swap '1'
option auto_mount '1'
option delay_root '5'
option check_fs '0'
config 'mount'
option target '/overlay'
option uuid 'ad3607ef-35a3-43dd-b014-8deca070c780'
option enabled '1'
root@GL-AR150:~# reboot
できました
root@GL-AR150:~# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 8192 8192 0 100% /rom
tmpfs 30088 252 29836 1% /tmp
/dev/sda1 7627412 47652 7172596 1% /overlay
overlayfs:/overlay 7627412 47652 7172596 1% /
tmpfs 512 0 512 0% /dev