howto/ganeti: fix real spelling mistakes caught by codespell

Pick something nice and document it in `tor-passwords`.

Also set reverse DNS for both IPv4 and IPv6 in [hetzner's robot](https://robot.your-server.de/)

(Chek under servers -> vSwitch -> IPs) or in our own reverse zone

(Check under servers -> vSwitch -> IPs) or in our own reverse zone

files (if delegated).

Then follow [howto/new-machine](howto/new-machine).

A disk can be added to an instance with the `modify` command as

well. This, for example, will add a 100GB disk to the `test1` instance

on teh `vg_ganeti_hdd` volume group, which is "slow" rotating disks:

on the `vg_ganeti_hdd` volume group, which is "slow" rotating disks:

    gnt-instance modify --disk add:size=100g,vg=vg_ganeti_hdd test1.torproject.org

    gnt-instance reboot test1.torproject.org

         gnt-instance failover $INSTANCE

         gnt-instance startup $INSTANCE

 14. redo IP adress change in `/etc/network/interfaces` and `/etc/hosts`

 14. redo IP address change in `/etc/network/interfaces` and `/etc/hosts`

 15. final functional test

IMPORTANT: a previous version of this article mistakenly indicated

that a new cluster-level tag had to be created for each service. That

method did *not* work. The [hbal manpage](http://docs.ganeti.org/ganeti/current/man/hbal.html#exclusion-tags) explicitely mentions that

method did *not* work. The [hbal manpage](http://docs.ganeti.org/ganeti/current/man/hbal.html#exclusion-tags) explicitly mentions that

the cluster-level tag is a *prefix* that can be used to create

*multiple* such tags. This configuration also happens to be simpler

and easier to use...

Another error that `gnt-cluster verify` can give you is, for example:

    - ERROR: node fsn-node-04.torproject.org: not enough memory to accomodate instance failovers should node fsn-node-03.torproject.org fail (16384MiB needed, 10724MiB available)

    - ERROR: node fsn-node-04.torproject.org: not enough memory to accommodate instance failovers should node fsn-node-03.torproject.org fail (16384MiB needed, 10724MiB available)

The solution is to [rebalance the cluster](#rebalancing-a-cluster).

         gnt-cluster verify

     If that takes a long time and eventually fails with erors like:

     If that takes a long time and eventually fails with errors like:

         ERROR: node fsn-node-03.torproject.org: ssh communication with node 'fsn-node-06.torproject.org': ssh problem: ssh: connect to host fsn-node-06.torproject.org port 22: Connection timed out\'r\n