Ceph SSD, do i need "discard" or "ssd emulation" in vm settings?

[potetpro]

As title says, does this do anything? any good? or any bad?

My guess is that Ceph handles this by it self.

Thanks

 

[elurex]

It still require kvm to send discard and ceph is capable of handling discard command and pass it to the corresponded osd

so enable discard should be enough.

 

[spirit]

the discard option at vm config is need to reclaim space when you delete file inside your vm. (and you also need discard mount option or run fstrim command inside your guest).