mdadm --create --verbose /dev/md0 --level=10 --raid-devices=4 /dev/sda /dev/sdb /dev/sdc /dev/sdd

could this be right? I am looking up the mdadm instructions. I won't do anything until told.

mdadm --create --verbose /dev/md0 --level=10 --raid-devices=4 /dev/sda /dev/sdb /dev/sdc /dev/sdd

could this be right? Doing a little research on mdadm. I'm not doing anything until told.

How do you delete a post you have accidentally made?????

You added --verbose in there. I showed --create=md0 I think it would work as "--create=md0 --verbose" instead.

update: verbose does not work with create

I posted exactly as I put in. Exactly as you wrote. It seemed to throw an error. I did a little research and that is where I found --verbose. I did not use it. This is exactly what I did.

root@openmediavault:~# mdadm --create=md0 --raid-device=4 --level=10 /dev/sda /dev/sdb /dev/sdc /dev/sdd
mdadm: option '--create' doesn't allow an argument
Usage: mdadm --help
for help

I did not see that.
Try "--create /dev/md0" and if that does not work then use "--create" and with that it should create /dev/md127/

root@openmediavault:~# --create /dev/md0
-bash: --create: command not found

I am a very literal person today. Do you mean "--create /dev/md0" or "mdadm --create /dev/md0"?

sorry, I meant to replace the previous command with this change

root@openmediavault:~# mdadm --create /dev/md0 --raid-device=4 --level=10 /dev/sda /dev/sdb /dev/sdc /dev/sdd
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.


root@openmediavault:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid10 sdd[3] sdc[2] sdb[1] sda[0]
5860268032 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
[>....................] resync = 0.2% (13060736/5860268032) finish=532.8min speed=182898K/sec
bitmap: 44/44 pages [176KB], 65536KB chunk

unused devices: <none>



root@openmediavault:~# mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Sat Jan 2 12:01:23 2021
Raid Level : raid10
Array Size : 5860268032 (5588.79 GiB 6000.91 GB)
Used Dev Size : 2930134016 (2794.39 GiB 3000.46 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Sat Jan 2 12:03:27 2021
State : clean, resyncing
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : near=2
Chunk Size : 512K

Consistency Policy : bitmap

Resync Status : 0% complete

Name : openmediavault:0 (local to host openmediavault)
UUID : c19fc57c:a2629c71:a54e493d:1509d62d
Events : 25

Number Major Minor RaidDevice State
0 8 0 0 active sync set-A /dev/sda
1 8 16 1 active sync set-B /dev/sdb
2 8 32 2 active sync set-A /dev/sdc
3 8 48 3 active sync set-B /dev/sdd

Excellent, now just the partitioning and formatting is needed.
Have you decided on BTRFS or other for that array?

The cat of /proc/mdstat does tell you that a full sync will take so you may want to wait for about 10 hours to do more. Enjoy the day while it finishes the resync.

Resync status is now at 1%. I am to be patient until 100% correct?

I am lost as to the partitioning but I think for now a LVM (this makes the 4 disks appear as 1 yes?) on ext4 (stable and lots of information out there about, yes?) after partitioning? I have some research to do on partitioning, purpose/strategy.

There is a program called "watch" the I can see the progress every 2 seconds, right? (watch /proc/md0)?

THANK YOU! Don't get your cape caught in the door.

The raid makes this a single device. Using LVM handles the partitioning.

Now you get to learn about LVM management.
You will need to create a volume group (vg), add a physical volume (pv), create a logical volume (lv), then format the lv partition.
The first step is to use gparted to create a single partition on /dev/md0 with type LVM. Then the rest of the steps can be followed here or here. Note the ability to use multiple physical devices in a VG, but you will only use one - the array. The names used for the VG and LVs are only examples so use what you wish for your system.

I can work with you if needed but read up and the guides should be useful. It is really easy to expand an LV if it gets near full so I suggest you start with about 1 TB size for the file system and expand it as needed. My raid array is one VG on one PV of about the same size as yours. I started with 1.5 TB in the LV when I moved the data from a single disk and over the past 4 years have grown it to now 3.5 TB at about 75% used. My videos use about 2 TB of that space. The array still has about 2 TB unused space.

1 members found this post helpful.

At 14%

LVM. Gotit! Got some reading to do. BTW, I try to look up the man pages on my OMV5 install and can't. I get ...

root@openmediavault:~# man watch
-bash: man: command not found

Do I have to install the manpages?

I suppose I should also create a user so I am not on root.

I forgot which distro you are on but the man command "should" be there, although you may need to install it. It is being expanded/replaced over time with the info command so try "info watch" and see if that works. However you should not need to keep that close watch on the progress. How much time does it now say is remaining?

Yes, you should create a user and routinely log in with that. It does not matter much until the initial admin steps are finished but will later.

Once the user is created the user should be added to sudo so logging in as root is no longer necessary. This should help if needed.

openmediavault (debian based)

19% now.

'info' not working either.

I have found tutorials on setting up users in OMV so I think I might have a handle on that but getting the man pages are troublesome.

'apt install man'?