home server

[RobertKH]

I also found this, but I am having a hard time figuring out what is important here...
http://www.linuxsa.org.au/mailing-li...3-07/1270.html

[RobertKH]

Here is what happened after I created my /dev/md0 array
Screenshot from 2013-03-24 23:16:22.jpg

Note there should be 4 drives in my status bar on the left. After creating two of them disappeared. Is this normal? Is there a line I missed here?

Also I've read that the array won't automatically start back up after a reboot. How do I get it to do that? What's that command look like?

[darkod]

OK, lets go step by step.

1. Those /dev/mapper/... devices look like LVM. Do you want to keep it or destroy it? Or redo it again from scratch?
2. When creating mdadm array from partitions that were once members of another array, you have to destroy the superblock info so that it won't interfere. I think the --create command destroyed it, but you wouldn't get those errors and warnings.
3. What status bar on the right are you exactly talking about, where you expect to see 4 disks? In the Disks application you can see 4 separate disks, plus one external usb (it looks like that). How many physical disks and of which sizes do you have?

To see which arrays are present in the configuration you can look into /etc/mdadm/mdadm.conf. All ARRAY definitions there will assemble at boot. Now, whether an assembled array will mount automatically or not that is a question of /etc/fstab, not mdadm. But all of that is easy to do later, lets first figure out what do you expect to have in your configuration/system and are you getting that.

Because honestly I don't understand it much. You have a mix of mdadm raid and LVM which seem unrelated. You would usually use them in relation, if you want to use LVM at all.

For example, you create one or mode mdadm md devices to give you raid redundancy protection, and then you configure LVM on top of those md devices. They will serve as base, foundation, for the LVM.

In your case, they seem unrelated.

[darkod]

One more thing. The discussion got quite large and many things were mentioned. I think it's time to summarize what you actually want to do, in order to have a clearer path forward.

So, as mentioned in my previous post, it would be nice to specify how many disks you have and their sizes, and to tell us what you want to configure: like how many arrays, what raid level, number of disks, etc. That could help so we can provide exact commands.

The software like FTP, mail, etc, that's for later. Lets start with HW configuration first because I believe that part is not done yet too.

[RobertKH]

Ok so let's start with drives. Right now I have 2 WD Red 1TB drives that I want to have in a single RAID1 array. I haven't done anything with the LVM so I am not so sure how they became logical. I also have a 500gb WD green for extra storage of movies or whatever that I don't need redundant (mirrored). Attached through USB is my 1TB Seagate FreeAgent Desk external HD. I was planning on backing up the RAID array to this for a little extra security. So if we just move forward with my 2x 1TB WD Red drives that might be a little more precise.

Let's start with what I have done based on what I wanted in mind. I have gone through already once and created this array. When I did that one of the drives on the dock disappeared, which looking back should have been normal. I could see /dev/md0 in the disks utility. Then I was thinking that something must have been wrong so I manually failed a drive in order to remove it. I went through this whole problem with /dev/md127 (which I found out in the disks utility)and finally figured out how to remove it. I also ran what I think was the zero superblock command. My array seemed to go away and after a restart I had both of my drives back. Then yesterday I started to rebuild the array and that is how we got to where we are... I think.

When I say status bar I meant dock. I am not actually sure what you call it in Ubuntu, but on a Mac it's the dock. On the left... not the right. I think I might be a bit dyslexic. <-- But I spelled that right!

So currently I can see the /dev/md0 in the disks utitility, but I do not know how to mount it or even move files to it as I can't seem to find the place to do so. Does that make sense?

[RobertKH]

Oops forgot to mention the 320gb Seagate that my OS is running on. That is the 2.5" drive in the pictures.

[darkod]

OK, I would like to address the possible LVM first. Add the lvm2 package (you might already have it, so if you do just continue), and scan for Physical Volume (partition used in LVM):

sudo apt-get install lvm2
sudo pvscan

Let us know if it finds a PV or not.

Another thing is the mdadm raid. To see what you have right now, post the output of these commands:

cat /proc/mdstat
cat /etc/mdadm/mdadm.conf
df -h

That should help us for a start.

[RobertKH]

OK so running pvscan I get this
PV /dev/sdc5 VG ubuntu lvm2 [297.85 GiB / 16.00 MiB free]
Total: 1 [297.85 GiB] / in use: 1 [297.85 GiB] / in no VG: 0 [0 ]
server@server-box:~$

When I run the mdadm stats I get the following
server@server-box:~$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdd1[1] sda1[0]
976629568 blocks super 1.2 [2/2] [UU]

unused devices: <none>
server@server-box:~$ cat /etc/mdadm/mdadm.conf
# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#


# by default (built-in), scan all partitions (/proc/partitions) and all
# containers for MD superblocks. alternatively, specify devices to scan, using
# wildcards if desired.
#DEVICE partitions containers


# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes


# automatically tag new arrays as belonging to the local system
HOMEHOST <system>


# instruct the monitoring daemon where to send mail alerts
MAILADDR root


# definitions of existing MD arrays


# This file was auto-generated on Wed, 20 Mar 2013 23:47:41 -0400
# by mkconf $Id$
ARRAY /dev/md0 metadata=1.2 name=server-box:0 UUID=f89f6f39:5fba213b:8237f121:d8f1b86a
server@server-box:~$ df -h
df: `/root/.gvfs': Permission denied
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/ubuntu-root 292G 6.4G 271G 3% /
udev 1.8G 12K 1.8G 1% /dev
tmpfs 715M 1.2M 714M 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 1.8G 284K 1.8G 1% /run/shm
none 100M 56K 100M 1% /run/user
/dev/sdc1 228M 54M 163M 25% /boot
/dev/sde1 932G 439G 493G 48% /media/server/1TB External
/dev/sdb1 466G 114G 352G 25% /media/server/B684-12A0





Does that help at all?

[RobertKH]

So here is my newest problem. I restarted my server and when I did so I ran into this /dev/md127 problem again. Why would it rename my array from md0 to md127?
md127.png

[RobertKH]

I found out how to restart my /dev/md0 raid although I don't want to have to run this every time.
server@server-box:~$ sudo mdadm --stop /dev/md127
mdadm: stopped /dev/md127
server@server-box:~$ sudo mdadm --assemble --scan
mdadm: /dev/md0 has been started with 2 drives.
so it changed back to /dev/md0 from the /md127 but I want it to boot that way.

I know I am getting ahead of where we just were, however I needed to rebuild after that restart.