Well it's EXT2 mounted as sda5. Looking at /proc/mounts it shows
/dev/sda5 /tmp/mnt/Lexar ext2 rw,nodev,relatime,user_xattr 0 0
It is shared via samba so I can see it in windows.
If opkg isn't found, yet Samba is sharing the volume, then it's likely the problem is the entware directory isn't being linked to '/tmp/opt' properly in '/jffs/scripts/post-mount.' A quick test of this is run 'ls /opt'. Do you see the entware directory contents listed out?
If no, then I'm wondering if you're referencing your "entware partition" by it's device name (/dev/sda5) rather than its volume label (/tmp/mnt/Lexar) in '/jffs/scripts/post-mount'. The latter is by far the safest way to go as the "dev" name can change between boots, while the label will always be the same.
So open your '/jffs/scripts/post-mount' file, and look at the block of code that should look something like:
if [ "$1" = "/tmp/mnt/Lexar" ] ; then
ln -nsf /tmp/mnt/Lexar/entware /tmp/opt
If you're seeing it reference "/dev/sda#" (probably not sda5), then change it to reference the label path instead and manually execute that script ("./post-mount /tmp/mnt/Lexar" from the /jffs/scripts directory) to see if it fixes things.
/etc/fstab is empty, busybox does not have fsck so i ran the health check in the gui, it ran but did not display any information, so I looked at syslog and it contains:
USB partition unmounted from /tmp/mnt/Lexar fail. (return -1, Bad file descriptor)
is it OK if fstab is empty?
fstab is not used by default in this environment, so being empty is normal.
The firmware does include a full set of fsck commands, but they're named differently based on the file system to be checked. For Linux filesystems (EXT#) the command is 'e2fsck' (they're all located in /usr/sbin).
Hopefully that helps. Let us know what you find.