[Last Call] Learn how to a build a cloud-first strategyRegister Now

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1223
  • Last Modified:

Need help with pvcreate

I have a WD ShareSpace NAS which is a POS.  No support.

I found a ton of people having the same problem I am having and there are some posted solutions.  I am having an error that they didn't have and I don't understand it.

On this page: http://community.wdc.com/t5/WD-ShareSpace/Datavolume-doesn-t-exist-message/td-p/4440/page/2

There are two posted solutions by fibreiv and Cohiba88.

One lists the solution as:
pvcreate /dev/md2
vgcreate lvmr /dev/md2
lvcreate -l 714329 lvmr -n lvm0
lvcreate -l 714218 lvmr -n lvm0
fsck.ext fsck.ext2 fsck.ext3
fsck.ext3 /dev/lvmr/lvm0
(read their post for more info)

The other lists the solution as:

mdadm --assemble /dev/md2 /dev/sda4 /dev/sdb4 /dev/sdc4 /dev/sdd4
pvcreate /dev/md2
vgcreate lvmr /dev/md2
lvcreate -l 714329 lvmr -n lvm0
fsck.ext3 /dev/lvmr/lvmr0
mount -t ext3 /dev/lvmr/lvmr0 /DataVolume -o rw,noatime
(read their post for more info)

I issued this command:
mdadm --assemble /dev/md2 /dev/sda4 /dev/sdb4 /dev/sdc4 /dev/sdd4

And received:
mdadm: /dev/md2 assembled from 3 drives - not enough to start the array while not clean - consider --force.

Then I try:
pvcreate /dev/md2

And receive:
No physical volume label read from /dev/md2
/dev/md2: Size must exceed minimum of 1024 sectors.
Failed to setup physical volume "/dev/md2"

I am stuck...

I really need to get my NAS up even if only temporarily so I can copy some important files off of it.
0
beapit
Asked:
beapit
  • 9
  • 5
1 Solution
 
arnoldCommented:
Run fdisk -l
To see the available drives and the available partitions.

Is /dev/md2 already defined or are you trying to create it from scratch?
Does each drive have a fourth partition?
You are trying to reassemble, so issuing pvcreate/veg create is not advisable.
0
 
beapitAuthor Commented:
Results of fdisk -l:
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/sda1               1          26      208844+  fd  Linux raid autodetect
/dev/sda2              27         156     1044225   fd  Linux raid autodetect
/dev/sda3             157         176      160650   fd  Linux raid autodetect
/dev/sda4             177      121601   975346312+  fd  Linux raid autodetect

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/sdb1               1          26      208844+  fd  Linux raid autodetect
/dev/sdb2              27         156     1044225   fd  Linux raid autodetect
/dev/sdb3             157         176      160650   fd  Linux raid autodetect
/dev/sdb4             177      121601   975346312+  fd  Linux raid autodetect

Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/sdc1               1          26      208844+  fd  Linux raid autodetect
/dev/sdc2              27         156     1044225   fd  Linux raid autodetect
/dev/sdc3             157         176      160650   fd  Linux raid autodetect
/dev/sdc4             177      121601   975346312+  fd  Linux raid autodetect

Disk /dev/sdd: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/sdd1               1          26      208844+  fd  Linux raid autodetect
/dev/sdd2              27         156     1044225   fd  Linux raid autodetect
/dev/sdd3             157         176      160650   fd  Linux raid autodetect
/dev/sdd4             177      121601   975346312+  fd  Linux raid autodetect

I don't totally understand what is going on.  I suspect that I am creating it from scratch, but I am not sure.

From the solutions at the top where I posted the questioni, does it look to you like it is being created from scratch?

Throughout that link I provided in the original question, there are 13 pages of people saying that it worked for them.  It did not appear to be a permanent solution.  I think it just allowed the volume and shares to be mounted and the data copied off.  Then the NAS is erased and recreated from scratch.

In a nutshell, here is the situation.  The NAS says there is no DATAVOLUME.  Since there is no DATAVOLUME, there is no access to the shares.  Many people have said that the commands allowed temporary access to the data so that it could be copied off and the storage destructively reconfigured.

mdadm --detail /dev/md0 returns:
/dev/md0:
        Version : 0.90
  Creation Time : Wed Jun  2 23:53:21 2010
     Raid Level : raid1
     Array Size : 208768 (203.91 MiB 213.78 MB)
  Used Dev Size : 208768 (203.91 MiB 213.78 MB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Sat Sep  1 11:44:14 2012
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0

           UUID : 60cc5e1c:622701f4:6dd2f708:6491739e
         Events : 0.109672

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
       2       8       33        2      active sync   /dev/sdc1
       3       8       49        3      active sync   /dev/sdd1


mdadm --detail /dev/md1 returns:
/dev/md1:
        Version : 0.90
  Creation Time : Wed Jun  2 23:53:21 2010
     Raid Level : raid1
     Array Size : 1044160 (1019.86 MiB 1069.22 MB)
  Used Dev Size : 1044160 (1019.86 MiB 1069.22 MB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Sat Aug 11 20:22:50 2012
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0

           UUID : 37e5dbbb:9addb814:db622b44:c7cdc32d
         Events : 0.11136

    Number   Major   Minor   RaidDevice State
       0       8        2        0      active sync   /dev/sda2
       1       8       18        1      active sync   /dev/sdb2
       2       8       34        2      active sync   /dev/sdc2
       3       8       50        3      active sync   /dev/sdd2

mdadm --detail /dev/md2 returns:
mdadm: md device /dev/md2 does not appear to be active.


cat /proc/mdstat returns:
Personalities : [linear] [raid0] [raid1] [raid5]
md1 : active raid1 sdd2[3] sdc2[2] sdb2[1] sda2[0]
      1044160 blocks [4/4] [UUUU]

md2 : inactive sda4[0] sdd4[3] sdc4[2] sdb4[1]
      3901384960 blocks
md0 : active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0]
      208768 blocks [4/4] [UUUU]

That is all I know.
0
 
arnoldCommented:
Try mdadm --scan --run /dev/md2 /dev/sd[a-d]4
mdadm --examine /dev/md2 --detail
mdamd --run /dev/md2 --force after the assembly and the device is reflected as inactive.


Once the array is online, pvdisplay, vgdisplay, lvdisplay should reflect the volumes that are /dev/md2 would show up without the need to recreate them.  The logical volume might be listed inactive, to make it active run vgchange -ay /dev/lvmr
0
VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

 
beapitAuthor Commented:
The first line gives me:
mdadm: --scan does not set the mode, and so cannot be the first option.
0
 
beapitAuthor Commented:
So I tried:
mdadm --assemble --scan --run /dev/md2 /sd[a-d]4

And got:
mdadm: /dev/md2 not identified in config file.
mdadm: /sd[a-d]4 not identified in config file.
0
 
arnoldCommented:
What are the contents of /etc/mdadm.conf?

Was it a raid5 volume?
0
 
beapitAuthor Commented:
The file does not exist.
0
 
beapitAuthor Commented:
Yes, RAID5.
0
 
arnoldCommented:
Retry the command you used and include --force as suggested.
You seemingly have a four drive raid 5. The assemble seems to point to a failure in one of them
Mdadm reports that three are not enough which seemingly strange.
Once you bring the array online, use lvmdiskscan, pvdisplay, vgdisplay, lvdisplay to see where the issue might be.
0
 
beapitAuthor Commented:
--force got me further.

mdadm --assemble /dev/md2 /dev/sd[a-d]4 --force
    mdadm: /dev/md2 has been started with 3 drives (out of 4).

pvcreate /dev/md2
    No physical volume label read from /dev/md2
    Physical volume "/dev/md2" successfully created

vgcreate lvmr /dev/md2
    Volume group "lvmr" successfully created

lvcreate -l 714218 lvmr -n lvm0
    Logical volume "lvm0" created

fsck.ext3 /dev/lvmr/lvmr0
    e2fsck 1.38 (30-Jun-2005)
    fsck.ext3: while trying to open /dev/lvmr/lvmr0
    The superblock could not be read or does not describe a correct ext2
    filesystem.  If the device is valid and it really contains an ext2
    filesystem (and not swap or ufs or something else), then the superblock
    is corrupt, and you might try running e2fsck with an alternate superblock:
        e2fsck -b 8193 <device>


lvmdiskscan
  /dev/sda  [      931.51 GB]
  /dev/md0  [      203.88 MB]
  /dev/md1  [     1019.69 MB]
  /dev/md2  [        2.72 TB] LVM physical volume
  /dev/sda3 [      156.88 MB]
  /dev/sdb  [      931.51 GB]
  /dev/sdb3 [      156.88 MB]
  /dev/sdc  [      931.51 GB]
  /dev/sdc3 [      156.88 MB]
  /dev/sdd  [      931.51 GB]
  /dev/sdd3 [      156.88 MB]
  4 disks
  6 partitions
  0 LVM physical volume whole disks
  1 LVM physical volume

pvdisplay
  --- Physical volume ---
  PV Name               /dev/md2
  VG Name               lvmr
  PV Size               2.72 TB / not usable 2.00 TB
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              714218
  Free PE               0
  Allocated PE          714218
  PV UUID               743ujW-vfGM-k5TX-xv7b-oPxF-4PwA-ASVDKI

vgdisplay
  --- Volume group ---
  VG Name               lvmr
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                255
  Cur LV                1
  Open LV               0
  Max PV                255
  Cur PV                1
  Act PV                1
  VG Size               2.72 TB
  PE Size               4.00 MB
  Total PE              714218
  Alloc PE / Size       714218 / 2.72 TB
  Free  PE / Size       0 / 0
  VG UUID               M7L28o-jAVa-tnBR-K48O-5yQO-91FE-iKb9VK

lvdisplay
  --- Logical volume ---
  LV Name                /dev/lvmr/lvm0
  VG Name                lvmr
  LV UUID                FWkuGA-Uw3S-KBR1-TfeK-cOsI-hVDj-SrfRpd
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                2.72 TB
  Current LE             714218
  Segments               1
  Allocation             next free (default)
  Read ahead sectors     0
  Block device           253:0

I really appreciate your time and help.  Getting closer!  Not sure how to read this.
0
 
beapitAuthor Commented:
Looks like there was a typo on the page.

fsck.ext3 /dev/lvmr/lvmr0

should have been
fsck.ext3 /dev/lvmr/lvm0

It's doing some stuff.  I'm getting excited!!
0
 
beapitAuthor Commented:
BTW, this is what it is doing:

fsck.ext3 /dev/lvmr/lvm0
    e2fsck 1.38 (30-Jun-2005)
    Couldn't find ext2 superblock, trying backup blocks...
    ext3 recovery flag is clear, but journal has data.
    Recovery flag not set in backup superblock, so running journal anyway.
    NASRAID: recovering journal
    Pass 1: Checking inodes, blocks, and sizes
0
 
beapitAuthor Commented:
Success!

You rock, thanks for the help!
0
 
arnoldCommented:
For future reference when an LVM is present, there is no need to run pvcreate/vgcreate
When you rerun pvcreate/vgcreate on a previously defined volume you are and might be overwriting reference points that could lead to data loss.
when trying to recover data bad words in options/commands are: initialize, create, build, sync, etc.
You have to be sure what you are looking at when resyncing/rebuilding to make sure that the data you have is not overwritten by data you do not want.

run mdadm --detail /dev/md2 to see which drive/partition of the four is being reflected as bad.
0

Featured Post

[Webinar] Cloud and Mobile-First Strategy

Maybe you’ve fully adopted the cloud since the beginning. Or maybe you started with on-prem resources but are pursuing a “cloud and mobile first” strategy. Getting to that end state has its challenges. Discover how to build out a 100% cloud and mobile IT strategy in this webinar.

  • 9
  • 5
Tackle projects and never again get stuck behind a technical roadblock.
Join Now