hi guys.
Could someone briefly explain how to access device flash (for edit file /etc/config/fstab) whenever external (USB) root mounted?
Sometimes it not quick fix manually unplug usb flash and access device flash.
Thank you
hi guys.
Could someone briefly explain how to access device flash (for edit file /etc/config/fstab) whenever external (USB) root mounted?
Sometimes it not quick fix manually unplug usb flash and access device flash.
Thank you
as per Flash Layout I tried to mount mtd2&3
|mtd2 - rootfs|
|mtd3 - rootfs_data|
but got error:
root@a81m3:/home/sam# mount /dev/mtd3 /tmp/mtd3
mount: mounting /dev/mtd3 on /tmp/mtd3 failed: Block device required
root@a81m3:/home/sam# mount /dev/mtd2 /tmp/mtd3
mount: mounting /dev/mtd2 on /tmp/mtd3 failed: Block device required
Thank you.
Use /dev/mtdblock3
instead of /dev/mtd3
.
This is the overlay filesystem so you will not see files that exist only in the ROM. But /etc/fstab is not a ROM file, so it will be at upper/etc/fstab.
The pre-made empty directory /mnt is planned for temporary mounting of a single filesystem. In order to mount at another point, the directory has to exist.
ok. jot it but whenever I've attempted to mount /dev/mtdblock3 I got error bellow
root@a81m3:/home/sam# mount /dev/mtdblock3 /mnt/mtdblock3/
mount: mounting /dev/mtdblock3 on /mnt/mtdblock3/ failed: Invalid argument
root@a81m3:/home/sam#
Any idea what's wrong?
Thank you mk24
maybe mount expects the filesystem type to come after -t, but I don't know the filesystem type... how to find it out?
Try mounting it directly on /mnt
. A mount point must exist, so if you want to mount to /mnt/mtdblock3
you need to mkdir /mnt/mtdblock3
first.
Filesystem type is usually auto-detected. If the router has NOR flash, the overlay filesystem is jffs2.
unfortunately it doesn't work:
root@a81m3:/home/sam# ls -l / | grep mnt
drwxr-xr-x 2 root root 4096 Mar 5 14:40 mnt
root@a81m3:/home/sam#
root@a81m3:/home/sam#
root@a81m3:/home/sam#
root@a81m3:/home/sam# mount /dev/mtdblock3 /mnt/
mount: mounting /dev/mtdblock3 on /mnt/ failed: Invalid argument
root@a81m3:/home/sam#
root@a81m3:/home/sam# mount -t jffs2 /dev/mtdblock3 /mnt/
mount: mounting /dev/mtdblock3 on /mnt/ failed: Invalid argument
root@a81m3:/home/sam#
I'm not sure what to say here since that works for me (-t jffs2 must be explicitly set). The partition is not still mounted somewhere else is it?
partition is not mounted:
root@a81m3:/home/sam# mount
/dev/root on /rom type squashfs (ro,noatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,noatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,noatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noatime)
/dev/sda1 on / type ext4 (rw,noatime,nodiratime,data=ordered)
tmpfs on /dev type tmpfs (rw,nosuid,relatime,size=512k,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,mode=600,ptmxmode=000)
debugfs on /sys/kernel/debug type debugfs (rw,noatime)
root@a81m3:/home/sam#
maybe router mounted it before switching to extroot?
root@a81m3:/home/sam# dmesg | grep mount_root
[ 10.214338] mount_root: loading kmods from internal overlay
[ 26.723079] mount_root: switched to extroot
root@a81m3:/home/sam#
in this case partition mounted but I don't see it whenever root switched to extroot.
What do you think?
Thank you Mike.
Initially during boot it mounts a standard root/overlay on internal flash then those are unmounted when switching to extroot. The entire / tree (other than psuedo-filesystems like /dev) is then on the external drive.
If you have physical access and can take some downtime you could try booting into failsafe mode then mount_root, or reboot without the external drive, which will make it stay internal as extroot fails.
I can remove usb drive and get access directly to device flash. I just configure it for remote location. I'd like to have some kind of "back door" if I need access to device flash, but router physically is far away...
Anyway Thanks for "brain storm"...