Re: [PATCH] btrfs-progs: add option to run balance as daemon

["Austin S. Hemmelgarn" <ahferroin7@gmail.com>]

On 2016-07-11 03:26, Tomasz Torcz wrote:
> On Tue, Jun 21, 2016 at 11:16:59AM -0400, Austin S. Hemmelgarn wrote:
>> Currently, balance operations are run synchronously in the foreground.
>> This is nice for interactive management, but is kind of crappy when you
>> start looking at automation and similar things.
>
>   It can be done with simplest systemd unit file:
> btrfs-balance@.service:
> ---
> [Unit]
> Description=btrfs balance for %I
>
> [Service]
> ExecStart=/usr/bin/btrfs balance start %I
> ExecStop=/usr/bin/btrfs balance cancel %I
> ---
>
>   It automates quite nicely and needs no additional code.
>
It's also entirely dependent on a couple of things:
1. You're running systemd (not everyone is, I'm certainly not).
2. You're only dealing with the local system.

The type of situation I'm thinking of is dealing with non-local systems. 
  For example, running something like this:
ssh user@remotehost btrfs balance start --background /
Keeping the SSH connection open for the duration of the balance has 
issues for some people (may close without keep-alive set, uses network 
bandwidth with keep-alive set, many people who are hosted have bandwidth 
quotas still), and it's extremely useful to have the option to fire and 
forget.