On Sun, Aug 30, 2015 at 12:52 AM, William Park <opengeometry@yahoo.ca> wrote:

On Sat, Aug 29, 2015 at 10:34:24PM -0500, o1bigtenor wrote:
> On Sat, Aug 29, 2015 at 9:30 PM, Lennart Sorensen <
> lsorense@csclub.uwaterloo.ca> wrote:
> > What entry do you have for your raid stuff in /etc/fstab?
...
> nothing listed for md0 or md/0

You can always add it. But, if manual mounting doesn't work, then
/etc/fstab won't work either.

> > And as already said, software raid does NOT use /dev/dm devices, it uses
> > /dev/md devices. dm is for device mapper, which you will see if you use
> > dmraid (which I think most people have fortunately stopped doing), or lvm
> > (which many people are using) or encrypted disks (which some people use).
> >
> > What does fdisk -l /dev/md0 show? Did you partition the raid or is the
> > filesystem on the full raid?
> >
>
>
> # fdisk -l /dev/md0
> Disk /dev/md0: 1.8 TiB, 2000403038208 bytes, 3907037184 sectors
> Units: sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 4096 bytes
> I/O size (minimum/optimal): 524288 bytes / 1048576 bytes
> Disklabel type: gpt
> Disk identifier: 1EB47793-0CDF-4E16-AE84-33EC825AC448

> sdb
> ??????sdb1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
> ??????md0
> sdc
> ??????sdc1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
> ??????md0
> sde
> ??????sde1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
> ??????md0
> sdf
> ??????sdf1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
> ??????md0

There is no filesystem on /dev/md0. It seems that it has GPT table with
no partitions. If you do
gdisk -l /dev/md0
you'll probably get similar result as 'fdisk -l'.

# gdisk -l /dev/md0
GPT fdisk (gdisk) version 1.0.0

Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/md0: 3907037184 sectors, 1.8 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): 1EB47793-0CDF-4E16-AE84-33EC825AC448
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 3907037150
Partitions will be aligned on 2048-sector boundaries
Total free space is 3907037117 sectors (1.8 TiB)

Number Start (sector) End (sector) Size Code Name

What is very interesting is that

# lsblk -f
NAME    FSTYPE            LABEL        UUID                                 MOUNTPOINT
sda
├─sda1 vfat                           8642-E734                            /boot/efi
├─sda2
├─sda3 ext4                           a3fbea19-5b7d-47af-b06c-08c49171211b /
├─sda4 swap                           354a6e33-5743-4c97-bfb9-fd6f9d4521e6 [SWAP]
└─sda5 ext4                           b36dbfc6-6897-4311-aa87-9a958ccad072 /home
sdb
└─sdb1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
└─md0
sdc
└─sdc1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
└─md0
sdd
├─sdd1 ext2                           a0ce336b-35cd-4413-a1c7-e77a1a4e91a6
├─sdd4
├─sdd5 ext4                           bbe77e50-0eaa-4048-934e-9f1b72b157ff
├─sdd6 ext4                           533f504b-30a6-4cf6-86e9-56772c87bae3
├─sdd7 ext4                           ff6bcbe9-f25f-4738-ba6b-5ea3c2fe0b70
├─sdd8 ext4                           2d0d1953-dae6-4e33-8d04-cc685e2e36fb
├─sdd9 ext4                           df754d9a-3dcf-470f-8e26-d38ef6f82df0
└─sdd10 swap                           04daef55-ff1b-4fe5-a897-ebe397a145b6 [SWAP]
sde
└─sde1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
└─md0
sdf
└─sdf1 linux_raid_member debianbase:0 79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3
└─md0
sr0

shows that I have two different identifiers for the array

# blkid
/dev/sda1: UUID="8642-E734" TYPE="vfat" PARTUUID="50750607-76d9-49ea-9319-25b4dc3325f2"
/dev/sda2: PARTLABEL="/boot" PARTUUID="784e5c57-6df4-4942-9eef-99c2c707c6e2"
/dev/sda3: UUID="a3fbea19-5b7d-47af-b06c-08c49171211b" TYPE="ext4" PARTLABEL="/" PARTUUID="0c2154c4-ccf8-44a8-a80a-8b27d9dd1da8"
/dev/sda4: UUID="354a6e33-5743-4c97-bfb9-fd6f9d4521e6" TYPE="swap" PARTLABEL="swap" PARTUUID="58495d3d-e71a-4412-bc8d-99710c326e5c"
/dev/sda5: UUID="b36dbfc6-6897-4311-aa87-9a958ccad072" TYPE="ext4" PARTUUID="b321042f-127c-4a29-b3a4-89ac3291093f"
/dev/sdb1: UUID="79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3" UUID_SUB="a80c76db-eaea-61af-bcb9-cbbbac99e467" LABEL="debianbase:0" TYPE="linux_raid_member" PARTUUID="000e4ced-01"
/dev/md0: PTUUID="1eb47793-0cdf-4e16-ae84-33ec825ac448" PTTYPE="gpt"
/dev/sdc1: UUID="79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3" UUID_SUB="840fc99d-6f60-7ea8-9a4a-9b0aa965c85c" LABEL="debianbase:0" TYPE="linux_raid_member" PARTLABEL="Linux filesystem" PARTUUID="a79c809a-0333-41d7-918a-e340febddcf4"
/dev/sdd1: UUID="a0ce336b-35cd-4413-a1c7-e77a1a4e91a6" TYPE="ext2" PARTUUID="000c9868-01"
/dev/sdd5: UUID="bbe77e50-0eaa-4048-934e-9f1b72b157ff" TYPE="ext4" PARTUUID="000c9868-05"
/dev/sdd6: UUID="533f504b-30a6-4cf6-86e9-56772c87bae3" TYPE="ext4" PARTUUID="000c9868-06"
/dev/sdd7: UUID="ff6bcbe9-f25f-4738-ba6b-5ea3c2fe0b70" TYPE="ext4" PARTUUID="000c9868-07"
/dev/sdd8: UUID="2d0d1953-dae6-4e33-8d04-cc685e2e36fb" TYPE="ext4" PARTUUID="000c9868-08"
/dev/sdd9: UUID="df754d9a-3dcf-470f-8e26-d38ef6f82df0" TYPE="ext4" PARTUUID="000c9868-09"
/dev/sdd10: UUID="04daef55-ff1b-4fe5-a897-ebe397a145b6" TYPE="swap" PARTUUID="000c9868-0a"
/dev/sde1: UUID="79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3" UUID_SUB="cb37e722-d3a9-8f88-1343-9de2bdad9d2b" LABEL="debianbase:0" TYPE="linux_raid_member" PARTUUID="000dc7e1-01"
/dev/sdf1: UUID="79baaa2f-0aa2-b9fa-18e2-ea6b6e2846b3" UUID_SUB="9e749fa9-a0ef-e791-ea09-d2e272b99f6c" LABEL="debianbase:0" TYPE="linux_raid_member" PARTUUID="0002d71f-01"

here it is even not a UUID its a PTUUID

Not sure what that means.

In that case, you have to follow through and create partitions on
/dev/md0. This is similar to regular harddisk /dev/sda with empty MBR
table, where you have to follow through and create partitions /dev/sda1,
etc.

It already has partitions. (Been running the array long enough to have disc failure.)

Talking you for your ideas and assistance.

Dee