cat /proc/mdstat is your best friend when running mdm raid. It tells you the current state of each "drive" as well as the state of the components. Example from my machine: Personalities : [raid1] md0 : active raid1 sda3[1] 243175808 blocks [2/1] [_U] unused devices: <none> I have one raid one device, md0. It has one dead device (the _). --- Wayne Johnson, | There are two kinds of people: Those 3943 Penn Ave. N. | who say to God, "Thy will be done," Minneapolis, MN 55412-1908 | and those to whom God says, "All right, (612) 522-7003 | then, have it your way." --C.S. Lewis >________________________________ > From: Mike Miller <mbmiller+l at gmail.com> >To: TCLUG Mailing List <tclug-list at mn-linux.org> >Sent: Monday, April 2, 2012 9:18 AM >Subject: Re: [tclug-list] testing that RAID1 is working using mdadm > >On Sun, 1 Apr 2012, Mr. B-o-B wrote: > >> 1) The Drive is Dead >> 2) The Drive is Disconnected >> 3) Something went terribly wrong, and was never set-up correctly. > >I'll be studying this further, but I would put my money on "1" because I remember hearing a strange noise coming from inside the box a few weeks ago. At the time I wondered if it was one of the HDDs. I wasn't sure how to check if they both were working. Then I forgot about it until now. > >That machine is important to me, but not as important as the other machine I am about to set up. In fact, the RAID1 on the machine in question was done partly as practice for setting up this other machine. > >Thanks *very* much, Mr. B-o-B for your help with this. You have done a lot for me and I really appreciate it. > >Mike >_______________________________________________ >TCLUG Mailing List - Minneapolis/St. Paul, Minnesota >tclug-list at mn-linux.org >http://mailman.mn-linux.org/mailman/listinfo/tclug-list > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mailman.mn-linux.org/pipermail/tclug-list/attachments/20120402/aa05cc49/attachment.html>