Forum Discussion

Aspirant

Apr 18, 2016

Solved

RN31600 and RAID1 with 5 disks

Hello all. I just bought a RN31600 and need to use it with 5 disks in RAID1 mode. However, as long as i put more than 2 disks in, the option only allows to create raid5 or raid6 with my 5 drives. I...

ReadyNAS OS 6 on Legacy models

Retired_Member

Apr 18, 2016

Creating a RAID1 on 5 HDDs is possible from SSH though.

Don't know if I should advise that, it depends on your experience in Linux systems.

I tried it on my unit and it worked:

## Switch to Flex-RAID from GUI
## Destroy the current volume from GUI (obviously, this wipes all data there is on it)

# mdadm --create --verbose /dev/md127 --level=mirror --raid-devices=5 /dev/sd[a-e]3
[...]
# cat /proc/mdstat
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md127 : active raid1 sde3[4] sdd3[3] sdc3[2] sdb3[1] sda3[0]
      483536832 blocks super 1.2 [5/5] [UUUUU]
      [>....................]  resync =  1.4% (6895616/483536832) finish=114.8min speed=69136K/sec


# mkfs.btrfs -L `hostid`:data /dev/md127
[...]
# mount /dev/md127 /data
mount: mount point /data is not a directory
# ls -al /data
lrwxrwxrwx 1 root root 9 Apr 18 03:50 /data -> /dev/null
# rm /data
# mkdir /data
# mount /dev/md127 /data
# mount | grep md127
[...]
# df -h
[...]

## Check that volume is seen from GUI
## Reboot gracefully from GUI to finalize procedure (so ReadyNAS OS mounts everything it needs,

anna_arun

NETGEAR Expert

Apr 18, 2016

Raid 1 does not function that way , Raid 1 with 5 Drives is not possible .Raid 1 or Raid 1+0 (Raid10) needs multiples of 2 Drives . Each HDD has a Mirror copy .

Best you can do is Raid 10 with 4 Drives and use one drive as hot spare or use 6 Drives on Raid10

Retired_Member

Apr 18, 2016

RAID1 with 1 HDD and 4 mirrors is a perfectly valid RAID. It's just not possible on ReadyNAS...

RAID1 and RAID10 are two different things.

Desmoquattro83
Aspirant
Apr 18, 2016
Agreed. Mirroring with RAID1 is perfect for me on 5 disks, and lower range ReadyNAS allow this ! (i already have a 314 which allows this on 3 disks inside + 1 disk outside.)
With RAID5 or RAID6, am I able to swap whatever drive i want from time to time .?
- Retired_Member
  Apr 18, 2016
  Again, I don't think this is a good idea, but you're master of your own property ;)
  On RAID5/6, the parity is distributed, so you can indeed swap whatever HDD.
  To achieve what you want, I wouldn't advise to use RAID5. Imagine you swap a drive and another drive goes bad... RAID5 has one parity, RAID6 has two.
  - Desmoquattro83
    Aspirant
    Apr 18, 2016
    Thank you very much for your information jak0lantash .
    I will then indeed use RAID6 !
    
    cheers
- StephenB
  Guru - Experienced User
  Apr 18, 2016
  Desmoquattro83 wrote:
  
  i already have a 314 which allows this on 3 disks inside + 1 disk outside.
  
  The R316 runs the same firmware as the RN314, so whatever you did to set it up on the 314 should work on the RN316.
  
  Personally I think you'd be better off using rsync to back up the array to a rotating group of USB drives.
  - Retired_Member
    Apr 18, 2016
    StephenB wrote:
    
    Personally I think you'd be better off using rsync to back up the array to a rotating group of USB drives.
    For sure, that's a better solution.
    Actually, (almost) everything is a better solution than swapping a HDD from the RAID1 itself. But op insisted :-P