Scp: ash: /usr/libexec/sftp-server: not found

[linuxuser]

scp openwrt-24.10.1-77dc5dac715a-ramips-mt7621-zyxel_wsm20-squashfs-sysupgrade.bin root@192.168.178.15:/tmp/
ash: /usr/libexec/sftp-server: not found
scp: Connection closed

Never used scp with OpenWrt 23.05.3, but earlier this was never a problem, using Ubuntu.

Why is sftp mentioned?

[d687r02j8g]

@linuxuser

sftp-server: not found

The vanilla OpenWrt out of the box has a small Dropbear SSH server. But it doesn't support the SFTP and you need to install openssh-sftp-server package.

[OpenWrt Wiki] SFTP server

[frollic]

Force SCP transfer instead of SFTP, no need to install anything.

[d687r02j8g]

@frollic

Force SCP transfer

Nice. "-O" option on scp. @linuxuser

scp -O openwrt-24.10.1-77dc5dac715a-ramips-mt7621-zyxel_wsm20-squashfs-sysupgrade.bin root@192.168.178.15:/tmp/

[AndrewZ]

Please use search.

Ash: /usr/libexec/sftp-server: not found when using scp

This is a consequence of your client machine using a very recent OpenSSH release (9.0 - check https://www.openssh.com/txt/release-9.0 for more info), which changes the scp program to use the SFTP protocol under the hood, which vanilla OpenWrt/dropbear installations do not support. To work around the problem on the client side, use the new -O (that is an uppercase letter "o") switch when invoking scp, which will cause it to fall back to the legacy behavior.

[linuxuser]

What do you mean by "force"?

So it looks like it makes sense to add openssh-sftp-server package to my list of packages which should be installed.

Earlier I had busybox installed as mentioned in WSM20 24.10.1 update with own image, could that be the difference? With the other thread there was no packages recommendation.

I am interested in an advice whcih packages make sense to install, when a lot space is avaiable.

[frollic]

@linuxuser

I am interested in an advice whcih packages make sense to install

None ? It's solvable anyway, as you can see.

[linuxuser]

My PC has:

-side library
ii  openssh-client                                 1:9.6p1-3ubuntu13.8                        amd64        secure shell (SSH) client, for secure access to remote machines
ii  openssh-server                                 1:9.6p1-3ubuntu13.8                        amd64        secure shell (SSH) server, for secure access from remote machines
ii  openssh-sftp-server                            1:9.6p1-3ubuntu13.8                        amd64        secure shell (SSH) sftp server module, for SFTP access from remote machines

@frollic

None ?

I meant the other methioned thread.

I used the webbrowser to upgrade, so there are solutions of course. Thanks for explaining, I didn't know this. There is no problem to connect via ssh and keys.

[systemcrash]

opkg install openssh-sftp-server or apk add openssh-sftp-server

Or as advised, use scp -O <file> root@192.168.1.1:/...

[linuxuser]

@systemcrash

or apk add openssh-sftp-server

I want to include it in the image, a few minutes ago online compilation didn't work with arp, but it worked 15min before. I will try later.

I have a lot devices which need this package.

[linuxuser]

@systemcrash

Or as advised, use ssh

You meant scp? ssh works without any option here.

In the meantime I compiled for the WSM20 without any errors and scp works without any option.

base-files ca-bundle dnsmasq dropbear firewall4 fstools kmod-crypto-hw-eip93 kmod-gpio-button-hotplug kmod-leds-gpio kmod-nft-offload libc libgcc libustream-mbedtls logd mtd netifd nftables odhcp6c odhcpd-ipv6only opkg ppp ppp-mod-pppoe procd-ujail uboot-envtools uci uclient-fetch urandom-seed urngd wpad-basic-mbedtls kmod-mt7915-firmware luci arp-scan arp-scan-database busybox iperf iperf3 iputils-arping nmap openssh-sftp-server static-neighbor-reports

root@WSM20-K0:~# ubus call system board
{
	"kernel": "6.6.86",
	"hostname": "WSM20-K0",
	"system": "MediaTek MT7621 ver:1 eco:3",
	"model": "Zyxel WSM20",
	"board_name": "zyxel,wsm20",
	"rootfs_type": "squashfs",
	"release": {
		"distribution": "OpenWrt",
		"version": "24.10.1",
		"revision": "r28597-0425664679",
		"target": "ramips/mt7621",
		"description": "OpenWrt 24.10.1 r28597-0425664679",
		"builddate": "1744562312"
	}
}