Add option for reserved storage

[dklesev]

With 0.7.0 release I saw there is tracking of available space and therefore no scheduling on a node with insufficient capacity happens (RESOURCE_EXHAUSTED_EXIT_CODE). This is great :)

Currently we have the following issue - it may happen that we have e.g. 100GB of storage on a node, single disk but we need to define how much space we can use for rawdisks (e.g. 50%) because there are other components which may need that amount of storage defined as "reserved".

Would it be possible to provide this in future?

[semekh]

Thanks for your interest in rawfile-localpv @dklesev. It is indeed possible to implement that. Are you more interested in having a percentage of disk as reserved or a fixed amount? I'm also not clear on what would be a good way to make the reservation value configurable enough.

Also, are you interested in sending a PR on that?