[Users] cluster.min-free-disk option on gluster 3.4 Was: Re: how to temporarily solve low disk space problem

[Amedeo Salvati]

Il 07/01/2014 18:00, users-request at ovirt.org ha scritto:
> Date: Tue, 7 Jan 2014 16:21:37 +0100
> From: Gianluca Cecchi<gianluca.cecchi at gmail.com>
> To: Gadi Ickowicz<gickowic at redhat.com>
> Cc: users<users at ovirt.org>
> Subject: Re: [Users] how to temporarily solve low disk space problem
> 	preventing start of VM
> Message-ID:
> 	<CAG2kNCxw54+dANqGX79j1HzjLYgPbxujxkb83GwVzZMfj=jNfA at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> On Tue, Jan 7, 2014 at 4:08 PM, Gadi Ickowicz  wrote:
>> >Hi,
>> >
>> >The low disk space is controlled by a parameter in the engine called FreeSpaceCriticalLowInGB, and can be configured using the cli tool engine-config.
>> >
>> >you should be able to set it to something like 4 GB or maybe 3GB so you can start your vms with the following command:
>> >
>> >engine-config -s FreeSpaceCriticalLowInGB=3
>> >
>> >After doing this you have to restart the engine service (service ovirt-engine restart) for the changes to take effect.
>> >
>> >If you want to see what the current value is use engine-config -g FreeSpaceCriticalLowInGB.
>> >
>> >
>> >To see a list of all configurable values you can use engine-config --list
>> >
>> >Thanks,
>> >Gadi Ickowicz
> It did the trick, thanks!
>
> Could this parameter impact in general only start of new VMs or in any
> way also already running VMs?
> Gianluca
added gluster-users as they can responde to us questions.

Gianluca, as you are using glusterfs, and as I can see on your df output:

/dev/mapper/fedora-DATA_GLUSTER                 30G   23G  7.8G  75%
/gluster/DATA_GLUSTER
node01.mydomain:gvdata                  30G   26G  4.6G  85%
/rhev/data-center/mnt/glusterSD/node01.mydomain:gvdata


be careful to gluster cluster.min-free-disk option, that on gluster 3.1 
and 3.2 it's default option is 0% (good for you!)

http://gluster.org/community/documentation//index.php/Gluster_3.2:_Setting_Volume_Options#cluster.min-free-disk

but I can't find the same documentation for gluster 3.4, that I suppose 
you're using this gluster version on ovirt; otherwise on red hat storage 
documentation cluster.min-free-disk default option is 10% (bad for you):

https://access.redhat.com/site/documentation/en-US/Red_Hat_Storage/2.1/html/Administration_Guide/chap-User_Guide-Managing_Volumes.html

so you fill your gvdata volume up to 90% and let we know if it's stop 
I/O (or only write) or we can wait for a clarification from gluster guy :-)

best regards
a

-- 
Amedeo Salvati
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email: amedeo at oscert.net
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