[elrepo] kmod-sata_via module for CentOS7

Tue Jul 20 18:58:18 EDT 2021

Hi Tristan,

That's great news, problem half solved!

Gmail decided to reject my off list email to you as it didn't like the 
binary attachments, hence you never received it.

We have published the script we use to make our ISO images here:

https://github.com/elrepo/elrepo-scripts/blob/master/mkdd.sh

Just place the RPM and SRPM in the same directory, and run the script:

./mkdd.sh kmod-foo-version-release.el7.elrepo.x86_64.rpm

which will create the ISO image for you, which you can then dd to a usb 
drive.

Regarding the installation, I've only ever used the `inst.dd` method 
when installing a driver for unsupported hardware. I think the issue 
here is that the hardware *is* supported by the (buggy) kernel driver. 
When the kmod driver is _replacing_ (updating) an existing kernel 
driver, we use an /etc/depmod.d/kmod-sata_via.conf file to tell depmod 
to override the in-kernel driver with our updated kmod driver. I suspect 
that override process isn't working during the installation hence the 
installer is using the existing kernel driver.

In terms of a solution, if the `inst.dd` method isn't working, I think 
you would need to create custom CentOS installation media with a patched 
kernel. It's simple enough to patch the kernel source code to backport 
the sata_via driver as per our kmod, but I have no idea how to then go 
about creating custom installation media with the patched kernel.

Maybe another easier alternative, if you have many identical machines, 
would be to clone an image your now successful base installation onto 
the HDDs of the remaining machines.

Following your confirmation that kmod-sata_via fixes the issue, I'll 
promote it to the main elrepo repository.

Phil

On 20/07/2021 20:04, Tristan Evans wrote:
> Thanks Phil! I actually didn't seem to get your email with the DUD (I 
> checked my "spam" just in case). Although I've used pre-made DUDs 
> before, I really struggled with manually creating the one I'm using, 
> which makes me wonder if that somehow plays into my issue. I ended up 
> downloading one from ELRepo, opened it up, replaced the RPM and SRPM 
> with the sata_via one and recreated the repository. I then made a new 
> .iso of that and wrote it to my thumb drive. After that, the CentOS 
> installer finally recognized it as a DUD.
> 
> And please, no need to apologize. I'm very appreciative of you and this 
> community helping me out.
> 
> So after playing around a bit, I made a little progress..
> 
> What I did was the following:
> 
>  1. Downloaded the KMOD RPM and wrote it to one USB stick.
>  2. Booted the CentOS 7 installation media from another USB stick.
>  3. The CentOS install environment loads with the intree sata_via module
>     and I begin installation. It is extremely slow, but it does
>     eventually finish.
>      1. Just to reiterate, even if I use the `inst.dd` kernel parameter
>         at boot and select the DUD with the RPM on it, it doesn't seem
>         to load into the CentOS installation environment (likely failing
>         to install it?), which is why the install is painfully slow.
>  4. Then from the same install environment, I mounted the disk the OS
>     was installed to and "chrooted" into it. I then installed the KMOD
>     RPM from the USB stick using `yum`. No need for an update. The
>     package install was super slow, but successful!
>  5. I then reboot and the OS loads perfectly fine with my flashy new
>     sata_via kernel module! 
> 
> So that is really awesome and proves that it fixes the issue with my 
> hardware!
> 
> But I'm still struggling with getting the CentOS installer environment 
> to load the KMOD using the `inst.dd` kernel parameter and the DUD. I 
> can't even manually install the RPM in that environment without the 
> mentioned dependency errors.
> 
> There must be something wrong with the environment I'm loading off of my 
> flash drive? The only thing I can think of is downloading the CentOS 7 
> minimal installer fresh and trying that. I am open to any other ideas 
> the community may have!
> 
> On Tue, Jul 20, 2021 at 1:23 PM Phil Perry <phil at elrepo.org 
> <mailto:phil at elrepo.org>> wrote:
> 
>     On 20/07/2021 17:31, Tristan Evans wrote:
>      > Thanks all, I'm still playing with it and will try all of your
>      > suggestions, then report back.
>      >
>      > The thing that complicates this is that I'm trying all of this
>     from the
>      > CentOS (minimal) installer environment loaded from a USB drive,
>     rather
>      > than the actual OS installed on the disk, as I can't actually get
>     the
>      > installed OS to load after installation (keeps falling into the
>      > emergency environment). I'm thinking a lot of my challenges may have
>      > something to do with that? However, I have had a lot of luck with
>      > loading other KMODs on other systems that have out-of-support
>     hardware
>      > (megaraid_sas) in this fashion (loading the RPM from a DUD using the
>      > "inst.dd" kernel parameter).
>      >
>      > I'm not exactly sure how to use `yum` in the installer
>     environment yet
>      > (looks like there is `anaconda-yum`, so I could possibly
>     experiment with
>      > that). I'm doing another fresh install of CentOS (it takes a
>     while) and
>      > then I'll try to `chroot` into that environment from the installer
>      > environment, and install the RPM with `yum`. If that doesn't
>     work, I'll
>      > do a `yum upgrade` and try again. I don't know if that is really
>     helpful
>      > or not, but I'm curious to see what happens.
>      >
>      > To shed a little light around my main goal is that I have a LOT
>     of these
>      > systems with this chipset that I'm trying to get onto CentOS 7 using
>      > Foreman, so it is ultimately important for me to be able to get the
>      > CentOS installer environment to load the KMOD RPM via a DUD,
>     which would
>      > ensure that the OS installs at a non-glacial pace and actually loads
>      > during boot :)
>      >
>      > Apologies if I'm making this overly complicated!
>      >
>      > Tristan
>      >
> 
>     Hi Tristan,
> 
>     I've sent you a DUD image for kmod-sata_via off list just in case, but
>     sounds like you already have a fair amount of experience working
>     with these.
> 
>     Apologies, in my earlier reply I'd assumed you had a working (albeit
>     slowly) installation - I didn't realise you couldn't boot into it.
> 
>     Phil
> 
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