C 7 Installation Annoyances

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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

12 thoughts on - C 7 Installation Annoyances

  • My favorite solution to above is: all my filesystems live on hardware RAID devices. No intermediate things like LVMs or software RAID. Just GPT label and “simple” partitions (or whatever synonym installer script is using). I know, you pay a bit more for hardware. But in addition to having more reliable IMHO system (I know, some people do not agree), you have simplicity, which also adds to reliability, and to speedy recovery from failures with much smaller room for blunders and data loss.

    Just my $0.02.

    Valeri

  • I was in the same boat with our newest servers. We went with all U.2 NVMe systems without hardware RAID. Yes, we’re running servers with and without hardware RAID for decades now and we didn’t regret our decision with two exceptions:

    1) the whole EFI thing seems a bit unfinished because it doesn’t handle our configuration well. Why should a newly developed system be so limited?

    2) the EL7 installer didn’t allow me to create the setup we wanted/needed

    For 1) I found a workaround which should work quite well in our case.

    For 2) my last resort was to install EL7 on a separate disk and then build/convert/move the whole system to the required configuration.

    It was quite a torture and I was a bit speechless. After decades of running all kinds of Unix and Linux systems it felt like a step backwards. It’s nice if things improve to make our life easier, but it should still be possible to do more complicated things, as it was the case in the older days.

    Regards, Simon

  • 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

  • *** 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—

  • Aye. It’s annoying that the text mode installer can’t manipulate partitioning at all — they lost that when they made the installer
    “better”. If it weren’t for that I’d never use the graphical installer.

    Similarly, switch to VT 2 (Alt+Ctrl+F2) just before going into the partitioner and do whatever you like with fdisk (etc) then switch back to the graphical installer and upon entry the first time rescan the drive(s).

    /mark

  • As best I recall, there’s no support in the UI for LVM volumes with RAID level. (And I don’t see any such option in the kickstart documentation, which also suggests that it won’t be present in the UI.) The supported configuration is to create two partitions, create a RAID1 volume from those, make that volume an LVM physical volume, and then any logical volumes in that VG will be backed by a RAID1 set.

  • I think you may be confused.  Neither MD RAID (software RAID) nor LVM
    RAID are related to hybrid RAID controllers.  Software RAID is well supported and reliable under Linux (provided that you have a UPS and properly configured monitoring and shutdown!), and Red Hat’s future storage plans (Stratis) are build on software RAID (device mapper).

  • I don’t think I follow you.  What I described creates a single RAID1
    volume, and then creates logical volumes within it.

  • Gordon Messmer wrote:

    I don’t seem to see your how-to-do-it today. All I know is that the GUI
    partitioner lets me *either* to lvm, *or* RAID, which results in two RAID
    partitions (root and swap), not one LVM on top of a single RAID 1
    partition.

    mark

  • —– Original Message —–

    LVM on a Linux software RAID1 is still easy to create. Here is a link to a tutorial someone made with screenshots.

    https://www.tuxfixer.com/CentOS-7-installation-with-lvm-raid-1-mirroring/

    Although I don’t use LVM much I do use Linux software RAID1 on all my production systems. I have a few dozen systems that use it under CentOS 6 and 7. It has always worked just fine and has saved me trouble from failing disks on quite a few occasions throughout the years.

    David Miller.

  • I agree and also use kickstart but sometimes, for a one-off install, I
    find it easier to partition first with the CentOS 6 installer and quit after the drives are partitioned. CentOS 7 can then be installed onto the existing partitions.