Having trouble setting up plex with my new Raid 5 setup

Plex Media Server Desktops & Laptops
1

First time posting about this so sorry if I am not doing it right. I used to have plex setup on my linux server with Raid 1 and had it working fine. Now I am trying to get it setup in a raid 5 since I added another 4TB HDD. I have a total of 3 4TB drives now. I am a beginner with linux and am having quite a bit of trouble getting this going. Please let me know what else i need to provide.

NAME      MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda         8:0    0   3.7T  0 disk  
└─sda1      8:1    0   3.7T  0 part  
  └─md127   9:127  0   7.3T  0 raid5 
sdb         8:16   0 465.8G  0 disk  
├─sdb1      8:17   0   512M  0 part  /boot/efi
├─sdb2      8:18   0 401.3G  0 part  /
└─sdb3      8:19   0    64G  0 part  [SWAP]
sdc         8:32   0   3.7T  0 disk  
└─sdc1      8:33   0   3.7T  0 part  
  └─md127   9:127  0   7.3T  0 raid5 
sdd         8:48   0   3.7T  0 disk  
└─sdd1      8:49   0   3.7T  0 part  
  └─md127   9:127  0   7.3T  0 raid5 
sde         8:64   1   3.8G  0 disk  
└─sde1      8:65   1   3.8G  0 part  /media/jason/D-LIVE 9_8_
sr0        11:0    1  1024M  0 rom

every time I try to mount my md127 it says that /dev/sdc1 is already mounted or /disks/Plex busy.

I am using mount /disks/Plex


# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda2 during installation
UUID=5a3cd776-8576-4d0b-beb8-295edb291c16 /               ext4    errors=remoun$
# /boot/efi was on /dev/sda1 during installation
UUID=802A-83E3  /boot/efi       vfat    umask=0077      0       1
# swap was on /dev/sda3 during installationUUID=a743f8b5-fb82-4336-a4ad-cf19776$
/dev/sr0        /media/cdrom0   udf,iso9660 user,noauto     0       0
#/dev/md0        /mnt/md0  defaults,noatime     0       2

#Mount Plex
UUID=7272ec60-9ac0-7307-1069-e5789dbc9d94 /disks/Plex ext4 defaults,auto,rw,nof$
2

As I read this:

  1. RAID members are: sda, sdc, and sdd which is a bit out of sequence.
  2. boot/system is on sdb. Normally sda is the boot/run device unless your cabling worked out differently?

Is this correct?

  1. You should have an entry for swap in fstab. Did you delete that by accident?
  2. What does mount | grep md127 and mount | grep md0 show?
  3. The contents of cat /proc/mdstat are?
3

When I setup the server I must have plugged in the cables that way. My old raid 1 was using sda and sdc if i recall correctly. I tried to delete the previous raid 1 and setup this new one but might have messed up something.

  1. as for deleting swap in fstab I do not remember doing that but it could have happened.
  2. When I type those commands in i do not see anything happen.
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md127 : active raid5 sdd1[3] sda1[0] sdc1[1]
      7813771264 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
      bitmap: 0/30 pages [0KB], 65536KB chunk

unused devices: <none>
4

@ChuckPa
If it would be better for me to start over I will do so. I tried before to completely format those 3 drives but kept getting an error that said they were in use.

5

How much difficulty would it be to to reinstall Linux and get the base OS stable?

I am thinking:

  1. Destroy the mdadm RAID which exists now
  2. Reinstall the OS
  3. Update it / get it ready
  4. Create the RAID volume on the 3 8TB drives
6

I have actually already started doing that. OS is reinstalled and now it is rebuilding the new raid.

NAME   MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda      8:0    0 465.8G  0 disk  
├─sda1   8:1    0   512M  0 part  /boot/efi
├─sda2   8:2    0 401.3G  0 part  /
└─sda3   8:3    0    64G  0 part  [SWAP]
sdb      8:16   0   3.7T  0 disk  
└─md0    9:0    0   7.3T  0 raid5 /disks/Plex
sdc      8:32   0   3.7T  0 disk  
└─md0    9:0    0   7.3T  0 raid5 /disks/Plex
sdd      8:48   0   3.7T  0 disk  
└─md0    9:0    0   7.3T  0 raid5 /disks/Plex
root@Server:/home/jason# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4] 
md0 : active raid5 sdd[3] sdc[1] sdb[0]
      7813774336 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [UU_]
      [===>.................]  recovery = 16.6% (650434584/3906887168) finish=365.5min speed=148464K/sec
      bitmap: 2/30 pages [8KB], 65536KB chunk

unused devices: <none>
7

that looks a LOT better

As test

mount /dev/md0   /mnt

Don’t forget mkfs -t ext4 if you’ve not done it

I use XFS for large volumes … works well for me.

8

i did this already

mkfs.ext4 -F /dev/md0
9

Then mount it up.

10

i thought i already had it mounted at /disks/Plex. Am I wrong about that?

11

what is fstab looking like since the installation?

I was suggesting reinstall, you stated you’d started.
You now have md0 versus md127 earlier.

12

I have not yet modified it yet but here is its current state.


# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda2 during installation
UUID=eae1b909-f918-49ed-a129-02974ac91141 /               ext4    errors=remount-ro 0       1
# /boot/efi was on /dev/sda1 during installation
UUID=802A-83E3  /boot/efi       vfat    umask=0077      0       1
# swap was on /dev/sda3 during installation
UUID=1a52461a-0b2d-4ab3-8bd0-f6a85f77036a none            swap    sw              0       0
13

Good

Now test mounting it manually

mount /dev/md0 /mnt

If this mounts successfully, we will next make the fstab entry

14

it changed my mountpoint from the /disks/Plex where I’d like to have it to just /mnt

root@Server:/home/jason# mount /dev/md0 /mnt
root@Server:/home/jason# lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda      8:0    0 465.8G  0 disk  
├─sda1   8:1    0   512M  0 part  /boot/efi
├─sda2   8:2    0 401.3G  0 part  /
└─sda3   8:3    0    64G  0 part  [SWAP]
sdb      8:16   0   3.7T  0 disk  
└─md0    9:0    0   7.3T  0 raid5 /mnt
sdc      8:32   0   3.7T  0 disk  
└─md0    9:0    0   7.3T  0 raid5 /mnt
sdd      8:48   0   3.7T  0 disk  
└─md0    9:0    0   7.3T  0 raid5 /mnt
root@Server:/home/jason#
15

excellent.

  1. Unmount it.
  2. Make the entry /dev/md0 /mount/dir/here ext4 auto,defaults,rw 1 2
  3. Test it mount /mount/dir (see if it maps to md0 correctly)
16

last time i built my raid 1 setup i had issues while it was located at /mnt. My server would error out on reboot until i changed the location (probably had nothing to do with the /mnt)

17

where am i putting that entry? in the fstab?

18

Yes Add it to the bottom of fstab

19

ok as soon as i did umount /dev/md0 and rand the lsblk it shows it still mounted on the /disks/Plex

20

so it should say this?

/dev/md0 /mount/disks/Plex ext4 auto,defaults,rw 1 2