[linux-lvm] Problem with partition table on LV

[linux-lvm] Problem with partition table on LV

[Mufit Eribol]

Hello,

After loosing all the data on my production server by issuing wrong lvm 
commands in restoring the logical volume, I have worked for weeks to 
setup my server again from scratch up. Now, today I noticed another 
problem, but scared to death to touch it.

This time I have to ask you before issuing any commands as obviously I 
haven't learned LVM internals.

Please find the details below. I would appreciate any help.

Thanks,
Mufit

Problem:
The system works but fdisk -l gives the following error:

[root@server ~]# fdisk -l
...
    Device Boot      Start         End      Blocks   Id  System

Disk /dev/sdc: 799.9 GB, 799937658880 bytes
255 heads, 63 sectors/track, 97253 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdc doesn't contain a valid partition table

Specs:
RHEL 5.1

/dev/sdc is a hardware raid array

/dev/raid_vg0/raid_lv0 -> /dev/mapper/raid_vg0-raid_lv0

[root@server ~]vi /etc/fstab
...
/dev/raid_vg0/raid_lv0  /mnt/raid               ext3    defaults        0 0

[root@server ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sdc
  VG Name               raid_vg0
  PV Size               745.00 GB / not usable 27.67 MB
  Allocatable           yes
  PE Size (KByte)       32768
  Total PE              23839
  Free PE               15
  Allocated PE          23824
  PV UUID               cyjzuJ-34VJ-l1S6-5Wcj-Qtw7-8Zcb-TR36bV

[root@server ~]# vgdisplay
  --- Volume group ---
  VG Name               raid_vg0
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               744.97 GB
  PE Size               32.00 MB
  Total PE              23839
  Alloc PE / Size       23824 / 744.50 GB
  Free  PE / Size       15 / 480.00 MB
  VG UUID               8XRQX4-g3bN-yaRB-RAG4-9qpx-7uXJ-p7VxYS

[root@server ~]# lvdisplay
  --- Logical volume ---
  LV Name                /dev/raid_vg0/raid_lv0
  VG Name                raid_vg0
  LV UUID                bYKncb-bUAW-FkFn-rYUr-O7RI-KL3y-18R0Oc
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                744.50 GB
  Current LE             23824
  Segments               1
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:0

[root@server ~]# pvscan
  PV /dev/sdc   VG raid_vg0   lvm2 [744.97 GB / 480.00 MB free]
  Total: 1 [744.97 GB] / in use: 1 [744.97 GB] / in no VG: 0 [0   ]

[root@server ~]# vgscan
  Reading all physical volumes.  This may take a while...
  Found volume group "raid_vg0" using metadata type lvm2

[root@server ~]# lvscan
  ACTIVE            '/dev/raid_vg0/raid_lv0' [744.50 GB] inherit

Re: [linux-lvm] Problem with partition table on LV

[David Robinson]

On Sat, Mar 29, 2008 at 01:33:58PM +0200, Mufit Eribol wrote:
> Hello,
>
> After loosing all the data on my production server by issuing wrong lvm 
> commands in restoring the logical volume, I have worked for weeks to setup 
> my server again from scratch up. Now, today I noticed another problem, but 
> scared to death to touch it.
>
> This time I have to ask you before issuing any commands as obviously I 
> haven't learned LVM internals.
>
> Please find the details below. I would appreciate any help.
>
> Thanks,
> Mufit
>
> Problem:
> The system works but fdisk -l gives the following error:
>
> [root@server ~]# fdisk -l
> ...
>    Device Boot      Start         End      Blocks   Id  System
>
> Disk /dev/sdc: 799.9 GB, 799937658880 bytes
> 255 heads, 63 sectors/track, 97253 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>
> Disk /dev/sdc doesn't contain a valid partition table

That's not an error. Its simply saying that there is no partition table on sdc.
You don't necessarily need a partition table. A lot of people actually setup
their system like this, especially when the device is from a SAN.

>  --- Physical volume ---
>  PV Name               /dev/sdc

LVM is using the correct device. You don't need to change anything.

> [root@server ~]# pvscan
>  PV /dev/sdc   VG raid_vg0   lvm2 [744.97 GB / 480.00 MB free]
>  Total: 1 [744.97 GB] / in use: 1 [744.97 GB] / in no VG: 0 [0   ]

--Dave

Re: [linux-lvm] Problem with partition table on LV

[Mufit Eribol]

David Robinson wrote:
>> Disk /dev/sdc doesn't contain a valid partition table
>>     
>
> That's not an error. Its simply saying that there is no partition table on sdc.
> You don't necessarily need a partition table. A lot of people actually setup
> their system like this, especially when the device is from a SAN.
>
>   
>>  --- Physical volume ---
>>  PV Name               /dev/sdc
>>     
>
> LVM is using the correct device. You don't need to change anything.
>
>   
>> [root@server ~]# pvscan
>>  PV /dev/sdc   VG raid_vg0   lvm2 [744.97 GB / 480.00 MB free]
>>  Total: 1 [744.97 GB] / in use: 1 [744.97 GB] / in no VG: 0 [0   ]
>>     
>
> --Dave
Sorry for being late. Thank you very much for your reply, Dave. I feel 
better.

Best wishes,
Mufit