Gluster users - Oct 2014 - If using ZFS with GlusterFS, why disable the ZIL?

In the Gluster community documentation, the ZFS Use Case [1] recommends
disabling the ZIL (intent log). Any thoughts on why that would be the case?
Much of the advice on tuning ZFS recommends against disabling the ZIL, so
I'm curious if there is a good reason why it should be done with Gluster.
The use case document certainly does not provide one.

Thanks

n


[1] http://gluster.org/documentation/use_cases/GlusterOnZFS/
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On 10/9/2014 6:23 AM, Nathan Fiedler wrote:
> In the Gluster community documentation, the ZFS Use Case [1] 
> recommends disabling the ZIL (intent log). Any thoughts on why that 
> would be the case? Much of the advice on tuning ZFS recommends against 
> disabling the ZIL, so I'm curious if there is a good reason why it 
> should be done with Gluster. The use case document certainly does not 
> provide one.
>
> [1] http://gluster.org/documentation/use_cases/GlusterOnZFS/
I've not done that myself but from how I read that document, the user 
did that because he instead configured an ARC cache to use up to 75% of 
the machine's 24Gb of RAM. This prevents the double-write of using an on 
disk journal at the cost of losing data in the event of power loss.