> Hi. > > CENTOS 7.6.1810, fresh install - use this as a base to create/upgrade > new/old machines. > > I was trying to setup two disks as a RAID1 array, using these lines > > mdadm --create --verbose /dev/md0 --level=0 --raid-devices=2 /dev/sdb1 > /dev/sdc1 > mdadm --create --verbose /dev/md1 --level=0 --raid-devices=2 /dev/sdb2 > /dev/sdc2 > mdadm --create --verbose /dev/md2 --level=0 --raid-devices=2 /dev/sdb3 > /dev/sdc3 > > then I did a lsblk and realized that I used --level=0 instead of --level=1 > (spelling mistake) > The SIZE was reported double as I created a striped set by mistake, yet I > wanted the mirrored. > > Here starts my problem, I cannot get rid of the /dev/mdX no matter what I > do (try to do). > > I tried to delete the MDX, I removed the disks by failing them, then > removing each array md0, md1 and md2. > I also did > > dd if=/dev/zero of=/dev/sdX bs=512 seek=$(($(blockdev --getsz > /dev/sdX)-1024)) count=1024 I didn't check but are you really sure you're cleaning up the end of the drive? Maybe you should clean the end of every partition first because metadata may be written there. > dd if=/dev/zero of=/dev/sdX bs=512 count=1024 > mdadm --zero-superblock /dev/sdX > > Then I wiped each partition of the drives using fdisk. > > Now every time I start fdisk to setup a new set of partitions I see in > /var/log/messages as soon as I hit "W" in fdisk: > > Feb 25 15:38:32 webber systemd: Started Timer to wait for more drives > before activating degraded array md2.. > Feb 25 15:38:32 webber systemd: Started Timer to wait for more drives > before activating degraded array md1.. > Feb 25 15:38:32 webber systemd: Started Timer to wait for more drives > before activating degraded array md0.. > Feb 25 15:38:32 webber kernel: md/raid1:md0: active with 1 out of 2 > mirrors > Feb 25 15:38:32 webber kernel: md0: detected capacity change from 0 to > 5363466240 > Feb 25 15:39:02 webber systemd: Created slice > system-mdadm\x2dlast\x2dresort.slice. > Feb 25 15:39:02 webber systemd: Starting Activate md array md1 even > though degraded... > Feb 25 15:39:02 webber systemd: Starting Activate md array md2 even > though degraded... > Feb 25 15:39:02 webber kernel: md/raid1:md1: active with 0 out of 2 > mirrors > Feb 25 15:39:02 webber kernel: md1: failed to create bitmap (-5) > Feb 25 15:39:02 webber mdadm: mdadm: failed to start array /dev/md/1: > Input/output error > Feb 25 15:39:02 webber systemd: mdadm-last-resort at md1.service: main > process exited, code=exited, status=1/FAILURE > > I check /proc/mdstat and sure enough, there it is trying to assemble an > Array I DID NOT TOLD IT TO DO. > > I do NOT WANT this to happen, it creates the same "SHIT" (the incorrect > array) over and over again (systemd frustration). Noooooo, you're wiping it wrong :-) > So I tried to delete them again, wiped them again, killed processes, wiped > disks. > > No matter what I do as soon as I hit the "w" in fdisk systemd tries to > assemble the array again without letting me to decide what to do. <don't try this at home> Nothing easier than that, just terminate systemd while doing the disk management and restart it after you're done. BTW, PID is 1. </don't try this at home> Seriously, there is certainly some systemd unit you may be able to deactivate before doing such things. However, I don't know which one it is. I've been fighting a similar crap: On HPE servers when running cciss_vol_status through the disk monitoring system, whenever cciss_vol_status is run and reports hardware RAID status, systemd scans all partition tables and tries to detect LVM2 devices and whatever. Kernel log is just filled with useless scans and I have no idea how to get rid of it. Nice new systemd world. Regards, Simon