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

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

[James Bottomley]

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.

James

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

[Bart Van Assche]

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.