Re: need help with RAID1 EFI GPT disks

Top Page
Attachments:
Message as email
+ (text/plain)
Delete this message
Reply to this message
Author: George Toft
Date:  
To: michael, Main PLUG discussion list
Subject: Re: need help with RAID1 EFI GPT disks
Hi Michael,

lsblk does not show the third partition, but gdisk knows it's there -
see below. See also results when trying to mount the 3rd partition.

[root@localhost ~]# ls -l /mnt
total 6
drwxr-xr-x. 2 root root 4096 Feb  2 15:33 raid
drwxrwxrwx. 1 root root 2304 Feb  2 15:46 sdd1
[root@localhost ~]# mount --read-only /dev/sdc3 /mnt/raid
mount: you must specify the filesystem type
[root@localhost ~]# mount --read-only -t ext4 /dev/sdc3 /mnt/raid
mount: special device /dev/sdc3 does not exist
[root@localhost ~]# lsblk
NAME                        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                           8:0    0 596.2G  0 disk
├─sda1                        8:1    0   500M  0 part /boot
└─sda2                        8:2    0 595.7G  0 part
   ├─VolGroup-lv_root (dm-0) 253:0    0    50G  0 lvm  /
   ├─VolGroup-lv_swap (dm-1) 253:1    0   7.8G  0 lvm [SWAP]
   └─VolGroup-lv_home (dm-2) 253:2    0 537.9G  0 lvm /home
sdb                           8:16   0   2.7T  0 disk
sdc                           8:32   0   2.7T  0 disk
├─sdc1                        8:33   0   200M  0 part
└─sdc2                        8:34   0     2G  0 part
sr0                          11:0    1   200M  0 rom
sdd                           8:48   0   3.7T  0 disk
└─sdd1                        8:49   0   3.7T  0 part /mnt/sdd1
[root@localhost ~]# gdisk /dev/sdc
GPT fdisk (gdisk) version 0.8.8


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

Found valid GPT with protective MBR; using GPT.

Warning! Secondary partition table overlaps the last partition by
4294968498 blocks!
You will need to delete this partition or resize it in another utility.

Command (? for help): p
Disk /dev/sdc: 5860531055 sectors, 2.7 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): BC837200-8528-4F8C-A78B-C529DA2B56CB
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1565563725
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
    1            2048          411647   200.0 MiB   EF00
    2          411648         4605951   2.0 GiB     8200
    3         4605952      5860532223   2.7 TiB     FD00


Command (? for help):




Maybe this is as simple as getting the Linux to see the 3rd partition?
I have another email in the works, but I'm waiting for the 3TB to dd to
another drive . . .

Regards,

George Toft

On 2/3/2014 12:23 AM, Michael Butash wrote:
> The only time I've used gpt with linux was with a efi-boot-only
> laptop, but prior I can raid the boot sector drive still with software
> and not have to use fakeraid at all for full partition redundancy.
> Still kind of a new concept for a lot of people I think. Ubuntu
> otherwise happily still uses mbr, so was a bit of a curve for me to
> have to adapt as they don't bake their gpt or raid tools well in the
> initrd or install.
>
> If you raided your /boot and *other* raid volume, I'd say just redo
> the partitions with gdisk and resync the raid which is pretty easy (I
> have to do this somewhat commonly with my ssd's). I can run swap and
> root from lvm on the raid otherwise for full redundancy and easy disk
> rebuilds if/when needed. That keeps failure recovery very easy. Only
> EFI complicates this with crappy non-raidable fat32 partitions needed
> now (eww, thanks microsoft).
>
> My gpt/efi laptop looks much the same with dual ssd's, but has the
> first partition as an identical fat32 partition on each to satiate
> ubuntu as /boot/EFI and /bootEFI1, plus a mdraided /boot second, and
> crypt volume third. If not adding encryption, lvm atop the mdraid pv
> for a lot more flexibility in volume/redundancy restoration among
> disks. I just rsync the stupid efi fat32 disks.
>
> mb@host:~$ lsblk
> NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
> sdh 8:112 0 111.8G 0 disk
> ├─sdh1 8:113 0 100M 0 part
> │ └─md127 9:127 0 100M 0 raid1 /boot
> └─sdh2 8:114 0 111.7G 0 part
> └─md126 9:126 0 111.7G 0 raid1
> └─spv0 (dm-0) 252:0 0 111.7G 0 crypt
> ├─vg0-root (dm-1) 252:1 0 2G 0 lvm /
> ├─vg0-swap (dm-2) 252:2 0 2G 0 lvm [SWAP]
> ├─vg0-var (dm-3) 252:3 0 2.5G 0 lvm /var
> ├─vg0-usr (dm-4) 252:4 0 10G 0 lvm /usr
> ├─vg0-home (dm-5) 252:5 0 32G 0 lvm /home
> sdi 8:128 0 111.8G 0 disk
> ├─sdi1 8:129 0 100M 0 part
> │ └─md127 9:127 0 100M 0 raid1 /boot
> └─sdi2 8:130 0 111.7G 0 part
> └─md126 9:126 0 111.7G 0 raid1
> └─spv0 (dm-0) 252:0 0 111.7G 0 crypt
> ├─vg0-root (dm-1) 252:1 0 2G 0 lvm /
> ├─vg0-swap (dm-2) 252:2 0 2G 0 lvm [SWAP]
> ├─vg0-var (dm-3) 252:3 0 2.5G 0 lvm /var
> ├─vg0-usr (dm-4) 252:4 0 10G 0 lvm /usr
> ├─vg0-home (dm-5) 252:5 0 32G 0 lvm /home
>
> -mb
>
>
>
> On 02/02/2014 08:44 PM, George Toft wrote:
>> installed gdisk and it looks like /dev/sdb is damaged, but /dev/sdc
>> is good :) doing a dd on the whole drive to a file on another drive
>> so I have a backup. I'll check back in a couple days when it's done.
>>
>> Regards,
>>
>> George Toft
>>
>> On 2/2/2014 2:58 PM, Matt Graham wrote:
>>>>> # fdisk -l | egrep "GPT|dev"
>>>>> WARNING: fdisk doesn't support GPT.
>>>>> /dev/sdb1 1 267350 2147483647+ ee GPT
>>>
>>>>> # mdadm --assemble --run /dev/md0 /dev/sdb1
>>>>> mdadm: cannot open device /dev/sdb1: No such
>>>>> file or directory
>>>
>>> This is an odd message to get, and probably means that udev didn't
>>> find the device and create it because udev and/or the rescue
>>> system's GPT support is flaking out. Does the kernel in this rescue
>>> system support GPT? "mknod /dev/sdb1 b 8 17" to create it. You may
>>> wish to "mknod /dev/sdc1 8 33" in case the other softRAID-1 disk has
>>> better stuff on it.
>>>
>>> As other people have said, there should be no need to use mdadm to
>>> assemble an array out of RAID-1 partitions. "mount /dev/sdb1
>>> /mnt/somewhere" should do something useful if the device node and
>>> /mnt/somewhere exist.
>>>
>>> On 2014-02-02 12:57, Michael Butash wrote:
>>>> Use gdisk if/when doing gpt
>>>
>>> That too. (One day, we will forsake our filesystems and break all
>>> bonds of block devices to get a disk larger than 2T for actual
>>> experience with GPT, but today is *not* this day. This day, we
>>> *SOLVE TECH PROBLEMS!!!1!*)
>>>
>>
>> ---------------------------------------------------
>> PLUG-discuss mailing list -
>> To subscribe, unsubscribe, or to change your mail settings:
>> http://lists.phxlinux.org/mailman/listinfo/plug-discuss
>
> ---------------------------------------------------
> PLUG-discuss mailing list -
> To subscribe, unsubscribe, or to change your mail settings:
> http://lists.phxlinux.org/mailman/listinfo/plug-discuss


---------------------------------------------------
PLUG-discuss mailing list -
To subscribe, unsubscribe, or to change your mail settings:
http://lists.phxlinux.org/mailman/listinfo/plug-discuss