How to create a software raid5 array without a spare

Solution 1:

This tutorial covers building a raid5 array with mdadm. You can't use raid5 with less than three devices.

What do you mean by a spare? Raid5 is designed to provide redundancy to survive the failure of one device. If it doesn't do that then it isn't raid5 anymore.

Edit after question edit:

   When creating a RAID5 array, mdadm will automatically create a degraded
   array with an extra spare drive.  This is because  building  the  spare
   into a degraded array is in general faster than resyncing the parity on
   a non-degraded, but not clean, array.  This feature can  be  overridden
   with the --force option.

That seems to be it, mdadm is setting up the new array as degraded with a spare, and then putting the spare in to build the array.

Solution 2:

if you got clean disks, and you are making a brand new array, the faster option around the initial rebuild is

(in my case)

mdadm --create --verbose --force --assume-clean /dev/md0 --level=5 --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1

Solution 3:

It also shows as currently recovering and your spare drive is showing rebuilding. I'd be interested to see what your output looks like after it finishes.