On 2/26/19 6:37 AM, Simon Matter via CentOS wrote: > How is it not systemd doing it? Such things didn't happen with pre systemd > distributions. The following log is from a CentOS 6 system. I created RAID devices on two drives. I then stopped the RAID devices and 'dd' over the beginning of the drive. I then re-partition the drives. At that point, the RAID devices auto-assemble. They actually partially fail, below, but the behavior that this thread discusses absolutely is not systemd-specific. What you're seeing is that you're wiping the partition, but not the RAID information inside the partitions. When you remove and then re-create the partitions, you're hot-adding RAID components to the system. They auto-assemble, as they have (or should have) for a long time. It's probably more reliable under newer revisions, but this is long-standing behavior. The problem isn't systemd. The problem is that you're not wiping what you think you're wiping. You need to use "wipefs -a" on each partition that's a RAID component first, and then "wipefs -a" on the drive itself to get rid of the partition table. [root at localhost ~]# dd if=/dev/zero of=/dev/vdb bs=512 count=1024 1024+0 records in 1024+0 records out 524288 bytes (524 kB) copied, 0.0757563 s, 6.9 MB/s [root at localhost ~]# dd if=/dev/zero of=/dev/vdc bs=512 count=1024 1024+0 records in 1024+0 records out 524288 bytes (524 kB) copied, 0.0385181 s, 13.6 MB/s [root at localhost ~]# kpartx -a /dev/vdb Warning: Disk has a valid GPT signature but invalid PMBR. Assuming this disk is *not* a GPT disk anymore. Use gpt kernel option to override. Use GNU Parted to correct disk. [root at localhost ~]# kpartx -a /dev/vdc Warning: Disk has a valid GPT signature but invalid PMBR. Assuming this disk is *not* a GPT disk anymore. Use gpt kernel option to override. Use GNU Parted to correct disk. [root at localhost ~]# cat /proc/mdstat Personalities : [raid1] unused devices: <none> [root at localhost ~]# parted /dev/vdb -s mklabel gpt mkpart primary ext4 1M 200M mkpart primary ext4 200M 1224M mkpart primary ext4 1224M 100% [root at localhost ~]# parted /dev/vdc -s mklabel gpt mkpart primary ext4 1M 200M mkpart primary ext4 200M 1224M mkpart primary ext4 1224M 100% [root at localhost ~]# cat /proc/mdstat Personalities : [raid1] unused devices: <none> [root at localhost ~]# cat /proc/mdstat Personalities : [raid1] md2 : active raid1 vdc3[1] vdb3[0] 19775360 blocks super 1.0 [2/2] [UU] md1 : active raid1 vdb2[0] 999360 blocks super 1.0 [2/1] [U_] md0 : active raid1 vdb1[0] 194496 blocks super 1.0 [2/1] [U_] unused devices: <none>