Mongo “illegal hardware instruction mongo” on Linux

While trying to install and run mongo on Kali Linux, I encountered the following error.

zsh: illegal hardware instruction mongo

Using a Bash shell it returns the following instead.

Illegal instruction

It appears that the issue is from running mongo in a virtual machine.

Resolution? Run on bare metal or find a way to enable avx2 in the virtual machine.

Searching for devices in UniFi via command line / MongoDB

While the UniFi controller is nice and everything, it does make it hard to see if a device is already adopted. At least if you have a ton of sites. Fortunately, we can search the database directly to find out if a UniFi is already adopted and which site it is assigned to.

Connect to Mongo DB

First we need to connect to MongoDB. And then we need to use the ace database.

mongo -port 27117
use ace

List all the devices on the controller

This command will list all the devices on the controller. Regardless of which site they are assigned to.

db.device.find({}, { site_id:"", ip : "", name :"", mac:""})

Example output

{ "_id" : ObjectId("563a4d94e4b054e5376fc600"), "mac" : { "_id" : ObjectId("563a4d94e4b054e5376fc600"), "mac" : "44:d9:e7:34:d1:08", "ip" : "", "name" : "Main_WiFi", "site_id" : "39485e9abf0e9a047bcded96" }
{ "_id" : ObjectId("9873b39ed1f5d30a6738abe"), "mac" : "44:d9:e7:01:a3:d4", "ip" : "", "name" : "Testing_Wifi", "site_id" : "39485e9abf0e9a047bcded96" }

Each UniFi will have a “site_id”. You can use that ID to figure out which site it is assigned to.

List all the sites on the controller

Example output

{ "_id" : ObjectId("39485e9abf0e9a047bcded96"), "name" : "default", "desc" : "Testing Site", "attr_hidden_id" : "default", "attr_no_delete" : true, "anonymous_id" : "83ae20ba-2948-458e-fd0a-1320583ecb04" }

Using our “site_id” from above, we see that the Testing_Wifi device is assigned to the “Testing Site” on the controller.

Something else to look at would be to use the UniFi controller API.

Change UniFi User Password from Command Line

  1. SSH into the UniFi server
  2. Connect to MongoDB
  3. Find user ObjectId
  4. Update user info with new Password

You will need a hash of the password to put into the database. We don’t cover that in this post. You could copy the password from a different user account or use a different UniFi instance to change the password and then check the DB to find the hash.

SSH into the UniFi Server

ssh unifiadmin@unifiserver

Connect to MongoDB

Connect to Mongo by typing in the following.

mongo -port 27117

Then select the ace database by typing

use ace

Find user ObjectId

The admins are in the admin collection/table. Use the following command to list all the users and their name, email, and password hash.

db.admin.find({ }, { name:"" , email : "", "x_shadow" : "" })

Update user info with new Password

The following looks complex. Fortunately though you should be able to copy and paste. You should only need to change the
– ObjectId to your User Id
– Password Hash to your password hash

db.admin.update({"_id" : ObjectId("223abc5489de0a93be758493")}, {$set: { "x_shadow" : "$6$nwpi7.q2$OuD9/UZGZt5cD739Dt7j8Gb1uPtfU99p0DeDSurSNBZVizieUrFVFbRufiZMgOk2IaaDZN9BVmL9yUwQ2mC8f."}});

Note: The hash above is password. Not recommended for use.

You should receive a confirmation that it succeeded. Test the new password by logging into the UniFi Controller.

For more MongoDB commands, check out this post.

unifi depends on mongodb-server (<< 1:3.6.0) | mongodb-10gen (<< 3.6.0) ...

Looks like the issue is that the UniFi server can’t be installed with a version of MongoDB newer then 3.6.0

Fix the issue by installing an older version of MongoDB

wget -qO - | sudo apt-key add -
echo "deb xenial/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list
sudo apt-get update

Then install MongoDB with

apt install mongodb-org-server

You may run into issues if you already have a version of Mongo installed. Uninstall it and then rerun the above install command.

Basic MongoDB commands

Connect to Mongo database


Connect to Mongo on a different port (May be needed.  Port is for UniFi server)

mongo -port 27117

Show Databases

show dbs

Use database

use dbname

Show tables/collections

show collections


show tables

List contents of table/collection


Example: (This example prints everything in the “admin” collection)


Find info that line that whose name is admin

 db.admin.find({name : "admin" })

Find everything in a table, but only print columns that are named “name, email, and x_shadow”

db.admin.find({ }, { name : "", email : "", "x_shadow" : "" })

List users

show users



Insert into table/collection

d = {"data":"data"}

Update a line, for example a users password.  Swap out the ObjectId for the ID that mongo gives you when you list the admins or users.  You will need to swap out the hash for the hash of the password you want.

db.admin.update({"_id" : ObjectId("a328bf90547ehc429a03ed85")}, {$set: { "x_shadow" : "$6$XB32GMXr$8dUt9huJzzL6O.gGZbs7QH1npldbzBzNDt/uUO1bI3b7Ij3YipgubtVHwincUUZjnDLh.KDI36uh2gUCID9yb1"}});


d = {"name":"admin","lang":"en_US","x_password":"password","time_created":"","last_site_name":"default"}

Delete line from table/collection


Example: (This will look for all the “rows” where the “name” contains “admin” and remove it)

db.admin.remove({ name: "admin"})

UniFI Specific

The following commands are specifically for a UniFi server.

Show UniFi Sites;


mongo --port 27117 ace --eval ";"

Show UniFi admins



mongo --port 27117 ace --eval "db.admin.find().forEach(printjson);"

Repair UniFi Video database

Stop the unifi-video service

sudo service unifi-video stop

Delete the journal with

rm -rf /usr/lib/unifi-video/data/db/journal/*

Switch to the unifi-video user

sudo su unifi-video

Repair the database

mongod --dbpath /var/lib/unifi-video/db --repair

Exit the user


Start the unifi-video service

service unifi-video start