From mboxrd@z Thu Jan  1 00:00:00 1970
From: stephen@networkplumber.org (Stephen Hemminger)
Date: Wed, 13 Jan 2016 10:51:22 -0800
Subject: NVM and swap device
In-Reply-To: <56968DBC.1040609@fb.com>
References: <20160112194030.5b74ecdc@xeon-e3>
	<56968DBC.1040609@fb.com>
Message-ID: <20160113105122.03fb7e63@xeon-e3>

On Wed, 13 Jan 2016 10:47:40 -0700
Jens Axboe <axboe@fb.com> wrote:

> On 01/12/2016 08:40 PM, Stephen Hemminger wrote:
> > I have a nice shiny new Intel NVM PCI card; decided to use it for a filesystem and swap.
> > The filesystem (btrfs) is doing fine, but the swap device was throwing occasional
> > random errors. Suspect a driver problem rather than hardware.
> >
> > I am using 4.4 kernel without patches.
> >
> > kern.log:Jan 12 08:11:57 xeon-e3 kernel: [159474.037390] Read-error on swap-device (259:0:17597808)
> > kern.log.1:Jan  7 08:32:10 xeon-e3 kernel: [87938.855526] Read-error on swap-device (259:0:11355648)
> > kern.log.1:Jan  7 08:32:10 xeon-e3 kernel: [87938.855530] Read-error on swap-device (259:0:11355656)
> > kern.log.1:Jan  7 08:32:10 xeon-e3 kernel: [87939.855467] Read-error on swap-device (259:0:16180824)
> > kern.log.1:Jan  8 08:24:07 xeon-e3 kernel: [63670.777981] Read-error on swap-device (259:0:32690768)
> > kern.log.1:Jan  9 09:25:02 xeon-e3 kernel: [153720.919325] Read-error on swap-device (259:0:220488)
> > kern.log.1:Jan  9 16:40:05 xeon-e3 kernel: [179820.957675] Read-error on swap-device (259:0:24476232)
> > kern.log.1:Jan  9 16:40:05 xeon-e3 kernel: [179820.962673] Read-error on swap-device (259:0:33292816)
> >
> > The swap device was being added via /etc/fstab by UUID.
> >
> > I gave up and went back to spinning rust for swap device for stabilty.
> 
> That's very odd. Why are you suspecting a driver problem? Have you tried 
> to thoroughly beat the device up with normal IO?
> 

I will try it tonight. Do you have a favorite test?