Re: [Lsf-pc] [LSF/MM TOPIC] A high-performance userspace block driver

[Bart Van Assche <Bart.VanAssche@wdc.com>]

On Tue, 2018-01-16 at 15:28 -0800, James Bottomley wrote:
> On Tue, 2018-01-16 at 18:23 -0500, Theodore Ts'o wrote:
> > On Tue, Jan 16, 2018 at 06:52:40AM -0800, Matthew Wilcox wrote:
> > > 
> > > 
> > > I see the improvements that Facebook have been making to the nbd
> > > driver, and I think that's a wonderful thing.  Maybe the outcome of
> > > this topic is simply: "Shut up, Matthew, this is good enough".
> > > 
> > > It's clear that there's an appetite for userspace block devices;
> > > not for swap devices or the root device, but for accessing data
> > > that's stored in that silo over there, and I really don't want to
> > > bring that entire mess of CORBA / Go / Rust / whatever into the
> > > kernel to get to it, but it would be really handy to present it as
> > > a block device.
> > 
> > ... and using iSCSI was too painful and heavyweight.
> 
> From what I've seen a reasonable number of storage over IP cloud
> implementations are actually using AoE.  The argument goes that the
> protocol is about ideal (at least as compared to iSCSI or FCoE) and the
> company behind it doesn't seem to want to add any more features that
> would bloat it.

Has anyone already looked into iSER, SRP or NVMeOF over rdma_rxe over the
loopback network driver? I think all three driver stacks support zero-copy
receiving, something that is not possible with iSCSI/TCP nor with AoE.

Bart.