We suddenly saw some failing CIFS (smb) mounts on servers in our (zabbix) monitoring.
Hurray for monitoring and especially also custom monitoring scripts that caught this specific error.
Huh? Why is it suddenly failing?
The error when (re)mounting the share:
mount error(112): Host is down
Pinging the host of course works just fine. 10 seconds of googling lead us to
this serverfault.com answer which
contained the solution: add vers=2.0 to your mount options.
The reason: if you’ve correctly (and recently) patched your windows servers, you’ve also disabled the SMB version 1 protocol. And somehow linux/smb doesn’t automatically detect version 2, so you have to set it explicitly.
There might be something that I’ve missed, but at least our CIFS mounts work again :-)
My name is Reinout van Rees and I work a lot with Python (programming language) and Django (website framework). I live in The Netherlands and I'm happily married to Annie van Rees-Kooiman.
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