Re: pre_start command not executed with upstart

[Wido den Hollander <wido@42on.com>]

On 28-07-15 14:29, Sage Weil wrote:
> On Tue, 28 Jul 2015, Wido den Hollander wrote:
>> Hi,
>>
>> I was trying to inject a pre_start command on a bunch of OSDs under
>> Ubuntu 14.04, but that didn't work.
>>
>> I found out that only the sysvinit script execute pre_start commands,
>> but the upstart nor the systemd scripts do this.
>>
>> Is this a thing which will disappear or is this just a oversight?
>>
>> I'm actually using "sleep 30" as a pre-start to prevent all OSDs from
>> starting at the same time. Big boxes which die under the workload of all
>> OSDs starting at the same time.
>>
>> I also try to prevent a lot of OSDMap changes by booting the OSDs slowly
>> so I tried to fix this with "pre_start".
> 
> I was hoping to let it die...
> 
> I would take a fresh look at systemd and see if there is a 
> different/better mechanism there to address the startup issue.  You can 
> manually add a prestart script/command to the unit file...
> 

Oh, it doesn't matter if it dies out. It's just that there will probably
be scenarios where users want to do some sort of pre-start before a OSD
is executed.

The update_crush hook is one of the examples which is already executed
for example.

A pre_start which does a mount for example (for those without udev)
might be useful.

Wido

> sage
>