Should I enable "SSD Emulation" for ceph images?

[cclloyd]

If I give a VM a hard drive from a ceph pool that uses only SSDs (separate pool for HDD), should I enable "SSD emulation" when creating the disk for the VM?

 

[Stefan_R]

"SSD Emulation" only tells the guest OS to treat the disk as a non-spinning disk (afaik it just sets the rotation rate to 0). It really shouldn't matter for most situations.

"Discard" on the other hand has a noticeable effect, read our documentation for more on that.

 

[blackpaw]

"SSD Emulation" only tells the guest OS to treat the disk as a non-spinning disk (afaik it just sets the rotation rate to 0). It really shouldn't matter for most situations.

For windows guests would it inform Windows that it should issue trim requests?

 

[Stefan_R]

No, that's the discard flag. In general, don't hesitate to open a new thread, instead of bumping really old ones.

 

[blackpaw]

Thanks! Will do.