Beware: bsd.rd files in 6.9 are gzipped / compressed!

[J65nko]

I was about doing a clean install of 6.9 on an existing 6.8 virtual private server in a data center, but just in time saw this posting on Re: Unable to boot 6.9 bsd.rd on 6.8 vmd host

Mischa writes:

> Hi All,
>
> I have a couple of machines running on 6.8 still, will upgrade soon.
> For some reason when I am trying to boot a 6.9 bsd.rd nothing is happening.

6.9 bsd.rd's for amd64 are gzip'd. For 6.9, vmd was taught how to boot
compressed kernels/ramdisks.

>
> It's only showing:
> Connected to /dev/ttypq (speed 115200)
>
> Nothing else appears.
> Booting from a 6.8 bsd.rd works normally.
>
> Equally booting from 6.9 bsd.rd on a 6.9 host works as expected as well.
>
> Something I can do to make this work?

gunzip the ramdisk and a 6.8 vmd instance should be able to boot it.

Once you have a guest updated and it's using seabios it will be booting
off the disk image and it shouldn't matter at that point.

That in 6.9 compressed bsd.rd ramdisk / installer files are being used, is mentioned in https://www.openbsd.org/69.html

Installer and upgrade improvements:

* Began distributing the gzip'd version of bsd.rd on all platforms with boot methods supporting it.

But sometimes you don't realize the consequences

[CiotBSD]

And for the FR user as I'm, what are the consequences of?
Need to unzip the bsd.rd before using?
as :

gunzip bsd.rd

?

[J65nko]

From https://www.openbsd.org/faq/faq4.html#bsd.rd

If you have a running OpenBSD system, bsd.rd is all you need to reinstall or upgrade to a newer version. To do so, download and verify the new bsd.rd, place it on an existing filesystem, and boot from it. The general method of booting bsd.rd is to change your boot kernel from /bsd to /bsd.rd through whatever means used on your platform.

Booting from bsd.rd on an amd64 system can be done like so:

Using drive 0, partition 3.
Loading......
probing: pc0 com0 com1 mem[638K 1918M a20=on]
disk: hd0+ hd1+
>> OpenBSD/amd64 BOOT 3.33
boot> bsd.rd

Alternative is to put this line into /etc/boot.conf and then reboot. The system will then load the ramdisk kernel/installer.

The issue is that 6.9 systems know that file]bsd.rd[/file] is compressed with gzip and thus can handle it.
6.8 systems don't know that and cannot load it and will fall-back on the standard /bsd kernel. That is why you need to unzip a 6.9 bsd.rd when you want to use it on a 6.8 system.

[CiotBSD]

Ah, OK, now I understand the issue. Ty!