bhyve and vfs.zfs.arc_max, and zfs tuning for a hypervisor

[Patrick M. Hausen]

Hi Matt,

> Am 20.03.2019 um 10:34 schrieb Matt Churchyard <matt.churchyard at userve.net>:
>>> 2. If ARC does cache volumes, does this cache make sense on a 
>>> hypervisor, because guest OSes will probably have their own disk cache anyway.
>> 
>> IMHO not much, because the guest OS is relying on the fact that when 
>> it writes it’s own cached data out to „disk“, it will be committed to 
>> stable storage.
> 
> Maybe I've missed something but I don't quite get the link between read cache (ARC) and guest writes here?

You are correct - I confused ARC and ZIL. I still recommend to
set sync=always for hypervisor „disk“ ZVOLs.

Kind regards
Patrick
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