Discuss December 2023

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6 participants
3 discussions

Issues booting centos7 [dracut is failing to enable centos/root, centos/swap LVs]
by Yannis Milios 01 Feb '25

01 Feb '25

Hello, I'm having a strange problem booting a new centos7 installation. Below some background on this. [I have attached the tech details at the bottom of this message] I started a new CentOS7 installation on a VM, so far all good, o/s boots fine. Then I decided to increase VM disk size (initially was 10G) to 13G. Powered off the VM, increased the vhd via the hypervisor, booted from CentOS livecd, selected "recover my centos installation". Then I used the following sequence of commands to make the new vhd size "visible" to the o/s ... - ran fdisk /dev/sda and deleted partition 2. (This is the LVM partition where the o/s is stored. The first partition is /boot [xfs] partition *non lvm*.) - created a new partition with same starting sector as before deleting it, but a different ending sector (to reflect to the increased space). - set partition type to 8e (lvm), saved settings and exit. - ran pvresize and lvresize to make new space visible to the o/s.All good, I can see the space increase on 'lvdisplay centos/root'. - ran 'mount /dev/mapper/centos-root /mnt/root' to temporarily mount the o/s partition. - ran 'xfs_growfs /mnt/root' to resize the o/s fs to the new size. It was successful and I could actually chroot to the o/s and verify new disk size. - rebooted and tried to boot from hdd this time. Grub menu shows up and loads default kernel (3.10.0-862.9.1.el7.x86_64). - after initial kernel boot up process, booting continues to initrd and then it's where the problem starts... - looks like dracut has issues locating/enabling /dev/mapper/centos-root (lv) and as a result it cannot boot to the 'real' root fs (/). - while in dracut shell, I execute the following command sequence: 1. lvm lvchange -ay /dev/centos/root 2. lvm lvchange -ay /dev/centos/swap 3. ln -s /dev/mapper/centos-root /dev/root 4. exit ...and the o/s boots fine...so looks like the pv,vg,lv is detected properly while in initrd, but somehow dracut has difficulties enabling the root,swap LVs ? - While in o/s, I rebuild initrd by using: 'dracut -f -v -a lvm' Note, I have to use '-a lvm' as for some reason, if don't, the lvm utils (lvm,lvm_scan) are not being included to the initrd, not sure why this happens. After rebooting, same thing happens, I have to manually boot the system via dracut shell. I'm a bit stuck at this point, any clues what I'm doing wrong in here ? As I previously said, this is a new installation, so I could simply reinstall the whole thing, but I would rather try to find out some answer to why is this happening ... :-) [curiosity] Some additional details: ================== I've attached /run/initramfs/rdsosreport.txt file [generated while in inird] here: https://privatebin.net/?fdc4052c0c402884#gdB/QYR3IeR55SxUbjfrkZPQfJ7jMxiUxq… o/s ver=CentOS Linux release 7.5.1804 (Core) [root@localhost ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 13G 0 disk ├─sda1 8:1 0 500M 0 part /boot └─sda2 8:2 0 12.5G 0 part ├─centos-root 253:0 0 11.5G 0 lvm / └─centos-swap 253:1 0 1G 0 lvm [SWAP] [root@localhost ~]# cat /etc/default/grub GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" GRUB_CMDLINE_LINUX="rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rd.shell rhgb" GRUB_DISABLE_RECOVERY="true"

4 11

resetting a serial port
by Robert Moskowitz 14 Dec '23

14 Dec '23

I have Centos 7 arm32 running on a Cubieboard and I am logged in as root on its serial uart from another system. On that system I use screen /dev/ttyUSB0 115200 Well it was working well for a couple days, but now only garbage comes across. Something messed up the serial link. pulling the usb cable to the usb/serial adapter does not reset things. I can ssh into the server and see root logged into ttyS0 How do I reset that serial port so that I can work on the system? thanks

5 7

mdadm: --update=resync not understood for 1.x metadata
by Strahil Nikolov 03 Dec '23

03 Dec '23

Hi All, Recently I had to update a host that uses raid1 for /boot and /boot/efi and I noticed that my resync service is failing with "mdadm: --update=resync not understood for 1.x metadata”. Does anyone know why 'mdadm-4.2-rc2.el8.x86_64.rpm’ supports it but 'mdadm-4.2-13.el8.x86_64’ not ? Why the version is not properly bumped if such drastic change is intentional ? Best Regards, Strahil Nikolov

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Discuss December 2023