[CentOS] Bare drive RAID question, was RE: *very* ugly mdadm issue [Solved, badly]

Fri Sep 5 13:18:42 UTC 2014
Richard Zimmerman <rzimmerman at riverbendhose.com>

>-----Original Message-----
>From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On Behalf Of m.roth at 5-cent.us
>Sent: Thursday, September 04, 2014 4:31 PM
>To: CentOS mailing list
>Subject: Re: [CentOS] *very* ugly mdadm issue [Solved, badly]
>Ok, folks,
>   Here's the answer: making a software RAID on a bare drive with no GPT works fine. If it has a GPT, and no partition, it fails on reboot, even with an /etc/mdadm.conf.
>   I've proved this:
>       first, I created the array on the bare drive, rebooted, and
>/dev/md0 was there;
>       then, I used parted to create a gpt, then the array, reboot, no md0, even with mdadm --assemble, even with /etc/mdadm.conf.
>       finally, I got rid of the disk label (parted to make an msdos label, the zeroing out the beginning of the disk), and again made the RAID on the bare drives, reboot, and md0 is there.
>   So that's what killed me. Admins, take heed....
>    mark

If you all would mind...

Until I read this thread, I've never heard of building RAIDs on bare metal drives. I'm assuming no partition table, just a disk label?

What is the advantage of doing this?

Many thanks,


Richard Zimmerman
Systems / Network Administrator
River Bend Hose Specialty, Inc.
1111 S Main Street
South Bend, IN   46601-3337
(574) 233-1133
(574) 280-7284 Fax