Unifi controller not starting, mongodb errors

[trainwreck]

I have Arch Arm installed on a raspberry pi 2. I am trying to setup the Unifi controller to manage some Unifi AC access points. I installed the unifi package via pacman. The unifi controller will not start. I have the following output in /var/log/unifi/server.log:

$this->bbcode_second_pass_code('', '[2016-01-16 01:04:11,673] <db-server> ERROR system - [exec] error, rc=100, output=2016-01-16T01:04:11.416-0600 I CONTROL [main] 2016-01-16T01:04:11.417-0600 W CONTROL [main] 32-bit servers don't have journaling enabled by default. Please use --journal if you want durability.2016-01-16T01:04:11.417-0600 I CONTROL [main]
[2016-01-16 01:04:11,674] <db-server> INFO db - DbServer stopped
[2016-01-16 01:04:16,971] <db-server> ERROR system - [exec] error, rc=100, output=2016-01-16T01:04:16.773-0600 I CONTROL [main] 2016-01-16T01:04:16.773-0600 W CONTROL [main] 32-bit servers don't have journaling enabled by default. Please use --journal if you want durability.2016-01-16T01:04:16.773-0600 I CONTROL [main]
[2016-01-16 01:04:16,971] <db-server> INFO db - DbServer stopped')

And this in /var/log/unifi/mongod.log:

$this->bbcode_second_pass_code('', '2016-01-16T01:04:16.777-0600 I CONTROL [main] ***** SERVER RESTARTED *****
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] MongoDB starting : pid=24989 port=27117 dbpath=/usr/lib/unifi/data/db 32-bit host=pLAN9-Server1
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] db version v3.2.0
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] git version: 45d947729a0315accb6d4f15a6b06be6d9c19fe7
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] OpenSSL version: OpenSSL 1.0.2e 3 Dec 2015
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] allocator: tcmalloc
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] modules: none
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] build environment:
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] distarch: arm
2016-01-16T01:04:16.817-0600 I CONTROL [initandlisten] target_arch: arm
2016-01-16T01:04:16.818-0600 I CONTROL [initandlisten] options: { net: { bindIp: "127.0.0.1", http: { enabled: false }, port: 27117 }, storage: { dbPath: "/usr/lib/unifi/data/db" }, systemLog: { destination: "file", logAppend: true, path: "logs/mongod.log" } }
2016-01-16T01:04:16.964-0600 I STORAGE [initandlisten] exception in initAndListen: 28663 Cannot start server. The default storage engine 'wiredTiger' is not available with this build of mongod. Please specify a different storage engine explicitly, e.g. --storageEngine=mmapv1., terminating
2016-01-16T01:04:16.964-0600 I CONTROL [initandlisten] dbexit: rc: 100')

Any ideas what is wrong? I could not find any configuration guide for the Unifi service that was specific to Arch Arm.....

[WarheadsSE]

$this->bbcode_second_pass_code('', '
The default storage engine 'wiredTiger' is not available with this build of mongod. Please specify a different storage engine explicitly, e.g. --storageEngine=mmapv1., terminating
')

Please read your output.

[trainwreck]

Yes, and I tried adding "storageEngine = mmapv1" to /etc/mongodb.conf, AND also tried modifying the mongodb systemd service file to add "--storageEngine=mmapv1" and then doing a "systemctl daemon-reload". Neither of these worked; I am still getting the same error messages.

[WarheadsSE]

Is Unifi running mongodb as a systemd service?

[trainwreck]

I'm not sure, how would I be able to tell? (I kind of don't think it is, since I changed the systemd unit file & the same error remains).

[WarheadsSE]

You'd need to locate how it is making the call to start mongo. This should be viewable from an strace, or htop with tree view.

[thantos]

You can try adding the below to /usr/lib/unifi/data/system.properties:
$this->bbcode_second_pass_code('', 'unifi.db.extraargs=--storageEngine mmapv1')

This mongodb is started by the unifi controller.