raid 1 with mdadm on 2 empty disks

tomislav91 · 09-01-2018, 06:35 AM

hello, i am making a raid 1 for my two new empty disks.
I have linux ubuntu server on several disk, and i make md0 array and mount it to /mnt/md0 folder.

i follow this tutorial
Link

I have one question.
I am making a samba share folder inside mounted /mnt/md0.
Folder path: /mnt/md0/test
Everything went fine, just one maybe not issue.
WHen i pulled out one disk, i lost my all data, when pulled in, data in /mnt/md0 is present.
When take out another, everything is ok.

My question is:
Is it secure to left it like this?
I didnt create any partitions on that 2 empty disks, just on md0 array (ext4 fs, like is in tutorial).
If one of my disks for data fail, will I have access to all data?

Code:

Filesystem                   Size  Used Avail Use% Mounted on
/dev/mapper/johnas--vg-root  223G  1.4G  210G   1% /
/dev/md0                     1.8T  898M  1.7T   1% /mnt/md0

Code:

lsblk -o NAME,SIZE,FSTYPE,TYPE,MOUNTPOINT
NAME                    SIZE FSTYPE            TYPE  MOUNTPOINT
sda                   232.9G                   disk
└─sda1                232.9G LVM2_member       part
  ├─johnas--vg-root     227G ext4              lvm   /
  └─johnas--vg-swap_1   5.9G swap              lvm   [SWAP]
sdb                     1.8T linux_raid_member disk
└─md0                   1.8T ext4              raid1 /mnt/md0
sdc                     1.8T linux_raid_member disk
└─md0                   1.8T ext4              raid1 /mnt/md0

Code:

root@myuser:/mnt/raid/test# cat /proc/mdstat
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdc[1] sdb[0]
      1953383488 blocks super 1.2 [2/2] [UU]
      bitmap: 0/15 pages [0KB], 65536KB chunk

unused devices: <none>

smallpond · 09-01-2018, 07:03 AM

I prefer to make RAID on partitions to leave room for a label and to simplify replacing a failed drive.

You should not lose access to your data with one failed drive. Can you post the error that you got?

tomislav91 · 09-01-2018, 09:05 AM

It just return me input output error. I cant read files.
I got message to /mnt/md0/test folder (files inside it).
It is just a test and trying to figure out this.

Just not have idea why it gives me that error.
Input Output error gives me just when went out ONE DISK, with another everything is fine.