ZFS I got an NVME U.2 SSD (actually two) to use as ZIL - now what?

[PMc]

I have never had to set a namespace on any of my NVMe. I am not sure why the descrepancy here.

That is strange indeed.
Maybe there is another way, without utilizing a namespace. Do You have these /dev/nvme0ns1 devices on your systems?

The OP here has set a second namespace when I don't see why. Please someone explain what I missed?

The OP apparently tries to do partitioning between a ZIL/SLOG and L2ARC by means of namespacing. I don't think that would be the best way, but there is also no consensus here if a ZIL/SLOG makes much sense at all for the given usecase.

Is this something new? Eight years at this and I never heard of an NVMe shipping without a namespace.

I don't know. I did once order my Fujitsu laptop (OEM, no OS), and it came with a WD blue 530, and that was the first nvme to fall in my hands. So I tried to find the way to get it running, and that led me into namespacing. The device will support only one namespace, but the size and, more interestingly, the blocksize had to be configured.

But then also, it is a habit of mine, when I touch some new technology, to explore the respective commands and all their options. So it is well possible, and I have a gift for it, to find ways of processing that are more complicated than usually done.

 

[sko]

every NVMe comes with a single namespace of the full disk size pre-configured. i.e. there is no need to touch the namespace configuration and in fact consumer drives don't support more than one (the default) namespace.

 

[rainer_d]

Thanks everybody for the great insight. I'm always amazed over just how much knowledge exists in this small community.

This is one of the few new physical servers I maintain (almost everything else is VMWare or Openstack, which are handled by different teams) and I don't usually work with SSDs.