[CentOS] C 7 installation annoyances

Tue Oct 16 12:54:03 UTC 2018
Young, Gregory <gregory.young at solarwinds.com>

*** This response is my personal opinion and may not reflect that of my employer. ***

It seems recent updates to Anaconda and in particular Blivet in the CentOS 7 .iso are restricting things rather than expanding the options. We have a scenario where we are doing a CentOS 6 to CentOS 7 upgrade (replacement) using a backup partition to hold the install image. Over the years, as we added cloud support to the CentOS 6 image, an error was made, and the AWS image became out of sync with the rest of our devices as LVM was used in AWS (bare BIOS partitions everywhere else). Upgrading to CentOS 7 using the backup physical partition works without issue. On AWS, because of the LVM in use, and the backup partition being on the LVM, we need to use the CentOS 7.3 versions of the isolinux and EFI kernels, initramdisk images and LiveOS image in order to install from the LVM partition. Starting with 7.4 (1708), there was a change within Anaconda, and in particular the Blivet packages on the LiveOS image, that no longer allows the install source to be on an LVM partition.

If you are having partitioning issues, I would suggest trying the 7.3 (1611) .iso and then updating the packages to 7.5 after initial install (or bundle the updated packages into the Packages folder of the 7.3 .iso). Also, for advanced partitioning, you are going to want to use a kickstart file. The Anaconda UI really seems to be going towards a KISS UX design.

As for the use of software RAID. Don't. They are useless, particularly with Linux. The trend seems to be moving away from supporting software RAID in Linux in general, and in particular, RHEL/CentOS 7.5 had to hard drop support for HBE (Hybrid) RAID controllers. I would expect to see onboard software RAID support get dropped in the near future (i.e. EL8 or EL9). If you have a hardware RAID controller, make sure it is EL7 supported... I find a properly configured hardware RAID will still appear as 2 or more disks to CentOS 7 if the hardware RAID controller is not EL7 certified (Servers: https://access.redhat.com/ecosystem/search/#/ecosystem/Red%20Hat%20Enterprise%20Linux?sort=sortTitle%20asc&certifications=Red%20Hat%20Enterprise%20Linux%207&architectures=x86_64&category=Server RAID controllers: https://access.redhat.com/ecosystem/search/#/ecosystem/Red%20Hat%20Enterprise%20Linux?certifications=Red%20Hat%20Enterprise%20Linux%207&architectures=x86_64&category=Component).


Gregory

-----Original Message-----
From: CentOS <centos-bounces at centos.org> On Behalf Of Nux!
Sent: October 16, 2018 6:05 AM
To: CentOS mailing list <centos at centos.org>
Subject: Re: [CentOS] C 7 installation annoyances

The EL7 partitioner is a complete disaster and I regularly bitch about it on twitter and irc.
You could try to convince it with kickstart and bypass the GUI altogether.
Another option is to boot in a Live CD and do you partitioning from there either manually or via Gparted and hope these changes will be picked up by the EL7 installer so you can just use them as they are.

hth

--
Sent from the Delta quadrant using Borg technology!

Nux!
www.nux.ro

----- Original Message -----
> From: "mark" <m.roth at 5-cent.us>
> To: "CentOS mailing list" <centos at centos.org>
> Sent: Monday, 15 October, 2018 21:22:57
> Subject: [CentOS] C 7 installation annoyances

> In the disk partitioner, I can't
>  1) choose to make the LVM with root and swap be on a RAID 1. Is there
>        some way to do that, rather than two separate partitions RAIDed?
>  2) They don't align, so I can't clone /dev/sda to /dev/sdb as a
>        failover (for /boot and /boot/efi). I've created those two, manually,
>        and nope, it wiped them out, so I can't clone those two.
> 
> Any solutions for either of these? I don't have hardware RAID card on 
> this box.
> 
>     mark
> 
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