[CentOS-virt] CentOS 8 Install as DOMU in PV Environment

Sun Sep 27 20:23:46 UTC 2020
9f9dcad3f78905b03201 at bcirpg.com <9f9dcad3f78905b03201 at bcirpg.com>

Christoph,

I understand this is the better option if HVM is available.. Im not sure how to make use of this kernel in a non-HVM, PV environment. I'm a little disturbed by the fact that there isnt PV support in CentOS 8, I hope it comes later so at least PVH becomes an option.

As for using this kernel in a PV only environment, the only route would be attempting an in place upgrade and try to install it as part of the upgrade. I am not willing to spend the time to do this and will use Centos 7 or other operating systems instead.


Thanks.


Christoph <mangel at gmx.de> wrote:
>the fastest/best mode is still pvh... use the kernel from elrepo it
>supports the mode
>
>---
>------
>Greetz
>
>Am 19.09.2020 19:08, schrieb Radosław Piliszek:
>> Hi,
>>
>> In general, PV tends not to be supported in newer distribution
>> releases.
>> This is mostly due to HVM performance and flexibility nowadays, which
>> just was not the case back in the days when PV ruled.
>>
>> I am curious why you are trying PV.
>>
>> -yoctozepto
>>
>> On Sat, Sep 19, 2020 at 6:41 PM 9f9dcad3f78905b03201--- via
>> CentOS-virt <centos-virt at centos.org> wrote:
>>>
>>> All,
>>>
>>> Just wanted to check one last time before letting this thread die.
>>>
>>> I am curious if anyone has gotten CentOS 8 to work in a PV Xen
>>> environment.
>>>
>>>
>>> Thanks.
>>>
>>>
>>> <9f9dcad3f78905b03201 at bcirpg.com> wrote:
>>> >All,
>>> >
>>> >I have successfully installed CentOS 7 on a PV environment, and have been trying to see if I can can get a CentOS 8 install running.
>>> >
>>> >Hardware does not support virtualization extensions, hence the PV environment and I cant do HVM for the install then migrate.
>>> >
>>> >My understanding is that PV support is in the kernel, and that the distro of Linux shouldn&#39;t technically matter. But currently when trying to &quot;PXEBoot&quot; using a CentOS 8 kernel and ram image I get a near instant crash for an invalid kernel.
>>> >
>>> >I tried to get around the issue by using DOM0 kernel and Ram Disk for the install (DOM0 is Debian 10), having the boot progress until it reaches the following, looping ISCSI error:
>>> >
>>> >&gt;[  OK  ] Reached target Slices.
>>> >&gt;         Starting Create Static Device Nodes in /dev...
>>> >&gt;[  OK  ] Started iSCSI UserSpace I/O driver.
>>> >&gt;[  OK  ] Started Setup Virtual Console.
>>> >&gt;         Starting dracut cmdline hook...
>>> >&gt;[  OK  ] Started Apply Kernel Variables.
>>> >&gt;[  OK  ] Stopped iSCSI UserSpace I/O driver.
>>> >&gt;         Starting iSCSI UserSpace I/O driver...
>>> >
>>> >I have also tried the CentOS 7 kernel Ram Disk with the same results.
>>> >
>>> >I even tried installing CentOS 7 clean, then upgrading in place (by unofficial and unsupported means) and was left with an error that pygrub couldnt find the partition with the kernel.
>>> >
>>> >Is this is a bug, or is PV just not supported? Or am I doing something wrong?
>>> >
>>> >Config for the install is below:
>>> >
>>> >&gt;# Kernel paths for install
>>> >&gt;#kernel = &quot;/var/opt/xen/ISO_Store/Centos8PXEBoot/vmlinuz&quot;
>>> >&gt;kernel = &quot;/vmlinuz&quot;
>>> >&gt;#ramdisk = &quot;/var/opt/xen/ISO_Store/Centos8PXEBoot/initrd.img&quot;
>>> >&gt;ramdisk = &quot;/initrd.img&quot;
>>> >&gt;extra=&quot;modules=loop,squashfs console=hvc0&quot;
>>> >&gt;
>>> >&gt;# Path to HDD and iso file
>>> >&gt;disk = [
>>> >&gt;        #&#39;file:/vmdisk0,xvda,w&#39;
>>> >&gt;        &#39;format=raw, vdev=xvda, access=w, target=/dev/mapper/vg_1-virtualmachine&#39;,
>>> >&gt;       ]
>>> >&gt;
>>> >&gt;extra=&quot;ksdevice= inst.repo=https://mirror.jaleco.com/centos/8.2.2004/isos/x86_64/ nameserver=1.1.1.1&quot;
>>> >&gt;
>>> >&gt;# Network configuration
>>> >&gt;vif = [&#39;bridge=xenbr0&#39;]
>>> >&gt;
>>> >&gt;#DomU Settings
>>> >&gt;memory = 3072
>>> >&gt;name = &quot;centos-8.2&quot;
>>> >
>>> >Thank you to all.
>>> >_______________________________________________
>>> >CentOS-virt mailing list
>>> >CentOS-virt at centos.org
>>> >https://lists.centos.org/mailman/listinfo/centos-virt
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