Solution for pvcreate error:  Device /dev/xyz not found (or ignored by filtering). Troubleshooting steps and resolution for this error.

Sometimes when adding new disk/LUN to Linux machine using pvcreate you may come across below error :

  Device /dev/xyz not found (or ignored by filtering).

# pvcreate /dev/sdb
  Device /dev/sdb not found (or ignored by filtering).

This is due to disk was used in different volume managers (possibly Linux own fdisk manager) and now you are trying to use it in LVM. To resolve this error, first, check if it has fdisk partitions using fdisk command :

# fdisk /dev/sdb

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): p

Disk /dev/sdb: 859.0 GB, 858993459200 bytes
255 heads, 63 sectors/track, 104433 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x62346fee6

    Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      104433   838858041   83  Linux

In the above example, you can print the current partition table of the disk using p option under fdisk menu.

You can see there is one primary partition detected using fdisk. Because of this LVM command to initialize this disk (pvcreate) failed.

To resolve this you need to remove this partition and re-initialize disk in LVM.  To delete partition use d option under fdisk menu.

# fdisk /dev/sdb

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help):d
Selected partition 1

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

After issuing delete d command under fdisk menu, you need to write (w) changes on disk. This will remove your existing partition on the disk. Once again you can use print p option to make sure that there is no fdisk partition on the disk.

You can now use disk in LVM without any issue.

# pvcreate /dev/sdb
  Physical volume "/dev/sdb" successfully created

If this solution doesn’t work for you or there were no partitions on disk previously and still, if you get this error then you may want to look at your multipath configurations. The hint is to look at your verbose pvcreate output to check where it’s failing. Use pvcreate -vvv /dev/<name> command.