Re: [vserver] 4.9 Kernels Hit Psand Repos

From: Andrew Ruthven <andrew.ruthven_at_catalyst.net.nz>
Date: Thu 20 Sep 2018 - 13:23:06 BST
Message-ID: <1537446186.13475.43.camel@catalyst.net.nz>

I decided to try the latest 4.9 kernel again tonight and I tracked down
the performance issue I was seeing. iostat was showing one hard drive
with utterly terribly wait times, and even running smartctl against
that drive was epically slow (all other drives ran normally).

Turns out there was a dodgy SATA cable for that drive. After swapping
the cable, I/O on the machine is back to what it should be!

At a guess something has changed in the SATA drivers between 4.1.x and
4.9.y and that change of behaviour triggered the issue I was observing.

Ben, thank you for publishing your kernels!

Cheers,
Andrew

On Mon, 2018-02-05 at 21:47 +1300, Andrew Ruthven wrote:
> Hey,
>
> Has anyone noticed big I/O issues with this kernel?
>
> I ran it for a few days, and found that processes (even on the main
> system) were often sitting in a D state, seemingly blocked on I/O.
> But
> there didn't seem to be much I/O happening. Even ssh'ing in to any
> vservers or physical host was incredibly slow.
>
> Cheers,
> Andrew
>
> On Tue, 2018-01-30 at 22:50 +0000, Ben Green wrote:
> > Hi all,
> >
> > I've just finished and uploaded Linux kernel 4.9.78 with patch  
> > vs2.3.9.6. They are installable directly from the psand.net  
> > repository, or via the metapackage:
> >
> > linux-image-vserver-4.9-beng
> >
> > For i386 and amd64 architectures, and there's a version I've
> > compiled  
> > with gcc-8 which can be installed directly, or via the metapackage:
> >
> > linux-image-vserver-4.9-beng-reptoline
> >
> > That one is amd64 only of course. These images are only provided
> > in  
> > the Debian Stretch distro repositories. Instruction (which need a
> > bit  
> > of updating but should get you where you need to be) are at:
> >
> > https://www.psand.net/services/public-repository.html
> >
> > These kernels are minimally tested and as usual come with
> > absolutely  
> > no guarantees whatsoever.
> >
> > Cheers,
> > Ben
> >

-- 
Andrew Ruthven, Wellington, New Zealand
MIITP
At work: andrew.ruthven@catalyst.net.nz
At home: andrew@etc.gen.nz
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Received on Thu Sep 20 13:14:43 2018
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