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Hi Mark,


On 10/03/2016 05:14, Mark Kirkwood wrote:
> On 10/03/16 00:03, Peter Brouwer wrote:
>>
>>
>> Indeed, I should have been a bit more clear with my question.
>> What is swifts behavior of a situation in which  a disk where a swift
>> partition points to runs out of space? There can be a number of swift
>> partitions that point to the same disk, does each partition gets a
>> certain capacity of the disk allocated?
>
> Hmm, I'm confused by the phrase 'partitions that point to the same disk':
PArtitions is used in the swift context, i.e. the partitions scheme the 
ring-builder uses. I'm assuming a whole physical disk is used, i.e. 
filesystem created on a disk using the whole physical disk.
So the ring structure provides a reference to a swift partition and a 
disk location, right?
What happens if the disk it is pointing to is full, does swift returns 
an error to the app/client or does it try a re-lookup in an attempt to 
find space elsewhere?
>
> - account, container, object rings can get set to use the same 
> *device* (typically an entire disk e.g /dev/sdc). While you could use 
> partitions e.g if you are sourcing storage from a SAN...this is not 
> the usual scenario.
> - they all 'compete' for the storage, however it is usually the 
> objects that eat the most of it (you can put the accounts and 
> containers on their own real disks to avoid this...I think the docs 
> suggest this as as a good practice).
>
>
> What happens when you run out of disk is that (eventually) you cannot 
> add any more objects or containers. Swift is pretty resilient and can 
> cope with *some* devices being full but eventually nothing can be done 
> and you need to add more storage nodes and amend ring configuration 
> (preferably *before* getting into the situation I described)!
>
> regards
>
> Mark
>

-- 
Regards,

Peter Brouwer, Principal Software Engineer,
Oracle Application Integration Engineering.
Phone:  +44 1506 672767, Mobile +44 7720 598 226
E-Mail: Peter.Brouwer at Oracle.com