[linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table

[linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table

[Sean McGlynn]

[-- Attachment #1: Type: text/plain, Size: 2588 bytes --]

Hello,

I did an fdisk -l to review my partition table (see results below), and found four entries that end with "Disk /dev/dm-X doesn't contain a valid partition table."  I don't recall seeing this in the past, so I believe it is something new.

I recently began using kernel 2.6.21.1, up from 2.6.9-42.  I don't know if perhaps this had some effect, or if the entries are normal and I just never noticed them.

What led me here is that sar -d output includes four entries for hard drives (dev253 entries) when there are only three on my system.  Fdisk is reporting four DM devices, so I'm thinking there is some correlation, but I don't know what.

Any constructrive feedback would be appreciated.

Thank you.

Disk /dev/sda: 1900.1 GB, 1900120375296 bytes
255 heads, 63 sectors/track, 231009 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1      231009  1855579761   8e  Linux LVM

Disk /dev/sdb: 146.1 GB, 146163105792 bytes
255 heads, 63 sectors/track, 17769 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1          38      305203+  83  Linux
/dev/sdb2              39       17769   142424257+  8e  Linux LVM

Disk /dev/sdc: 146.1 GB, 146163105792 bytes
255 heads, 63 sectors/track, 17769 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1       17769   142729461   8e  Linux LVM

Disk /dev/dm-0: 137.4 GB, 137405399040 bytes
255 heads, 63 sectors/track, 16705 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/dm-0 doesn't contain a valid partition table

Disk /dev/dm-1: 8388 MB, 8388608000 bytes
255 heads, 63 sectors/track, 1019 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/dm-1 doesn't contain a valid partition table

Disk /dev/dm-2: 146.1 GB, 146150522880 bytes
255 heads, 63 sectors/track, 17768 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/dm-2 doesn't contain a valid partition table

Disk /dev/dm-3: 1900.1 GB, 1900111986688 bytes
255 heads, 63 sectors/track, 231008 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/dm-3 doesn't contain a valid partition table


      ____________________________________________________________________________________Shape Yahoo! in your own image.  Join our Network Research Panel today!   http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7 


[-- Attachment #2: Type: text/html, Size: 3976 bytes --]

Re: [linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table

[Bryn M. Reeves]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Sean McGlynn wrote:
> Hello,
> 
>  
> 
> I did an fdisk -l to review my partition table (see results below), and
> found four entries that end with "Disk /dev/dm-X doesn't contain a valid
> partition table."  I don't recall seeing this in the past, so I believe
> it is something new.

Later kernels include dm devices in the list of partitions in proc, so
fdisk will attempt to scan them for partition tables. It's not harmful,
just noise.

> I recently began using kernel 2.6.21.1, up from 2.6.9-42.  I don't know
> if perhaps this had some effect, or if the entries are normal and I just
> never noticed them.

If you don't like it & you've not configured anything to use /dev/dm-*
devices directly (instead of /dev/mapper/* or /dev/<volgroup>/* or
whatever) then you can reconfigure udev to not create the dm-* nodes.

- From memory, you need to comment out the rule that begins
"KERNEL="dm-[0-9]*" in /etc/udev/rules.d/50-udev.rules, or, for newer
udevs you can add ignore_device:

KERNEL=="dm-[0-9]*", ACTION=="add", OPTIONS+="ignore_device"

>  
> 
> What led me here is that sar -d output includes four entries for hard
> drives (dev253 entries) when there are only three on my system.  Fdisk
> is reporting four DM devices, so I'm thinking there is some correlation,
> but I don't know what.

Those "dev253" entries are your device-mapper devices. Take a look at
/dev/dm-* with ls -l and you will see that the major number is 253.

Kind regards,
Bryn.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org

iD8DBQFGUayT6YSQoMYUY94RAqJKAJ9dFJtaRg3fONo7kLOkDezcS/FizwCcDwFj
2McvW5Wl+zudmUZDO2aE1fQ=
=NHOE
-----END PGP SIGNATURE-----

Re: [linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table

[Sean McGlynn]

[-- Attachment #1: Type: text/plain, Size: 2624 bytes --]

Bryn,

Thank you for taking the time to reply.

I'm glad to see this is not an issue. 

As for "dev253," if I only have three physical devices, why four dm entries?

Thanks again.


----- Original Message ----
From: Bryn M. Reeves <breeves@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>
Sent: Monday, May 21, 2007 10:28:35 AM
Subject: Re: [linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Sean McGlynn wrote:
> Hello,
> 
>  
> 
> I did an fdisk -l to review my partition table (see results below), and
> found four entries that end with "Disk /dev/dm-X doesn't contain a valid
> partition table."  I don't recall seeing this in the past, so I believe
> it is something new.

Later kernels include dm devices in the list of partitions in proc, so
fdisk will attempt to scan them for partition tables. It's not harmful,
just noise.

> I recently began using kernel 2.6.21.1, up from 2.6.9-42.  I don't know
> if perhaps this had some effect, or if the entries are normal and I just
> never noticed them.

If you don't like it & you've not configured anything to use /dev/dm-*
devices directly (instead of /dev/mapper/* or /dev/<volgroup>/* or
whatever) then you can reconfigure udev to not create the dm-* nodes.

- From memory, you need to comment out the rule that begins
"KERNEL="dm-[0-9]*" in /etc/udev/rules.d/50-udev.rules, or, for newer
udevs you can add ignore_device:

KERNEL=="dm-[0-9]*", ACTION=="add", OPTIONS+="ignore_device"

>  
> 
> What led me here is that sar -d output includes four entries for hard
> drives (dev253 entries) when there are only three on my system.  Fdisk
> is reporting four DM devices, so I'm thinking there is some correlation,
> but I don't know what.

Those "dev253" entries are your device-mapper devices. Take a look at
/dev/dm-* with ls -l and you will see that the major number is 253.

Kind regards,
Bryn.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org

iD8DBQFGUayT6YSQoMYUY94RAqJKAJ9dFJtaRg3fONo7kLOkDezcS/FizwCcDwFj
2McvW5Wl+zudmUZDO2aE1fQ=
=NHOE
-----END PGP SIGNATURE-----

_______________________________________________
linux-lvm mailing list
linux-lvm@redhat.com
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/


       
____________________________________________________________________________________
Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games.
http://sims.yahoo.com/  

[-- Attachment #2: Type: text/html, Size: 4387 bytes --]

Re: [linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table

[Bryn M. Reeves]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Sean McGlynn wrote:
> Bryn,
>  
> Thank you for taking the time to reply.
>  
> I'm glad to see this is not an issue. 
>  
> As for "dev253," if I only have three physical devices, why four dm entries?
>  
> Thanks again.
> 

The "dev253" entries are the logical volumes (or other device-mapper
devices), not the physical devices themselves.

I see you have three PVs in the volume group (sda1, sdb2 & sdc1), but
how many LVs do you have in your volume group?

Just post the output of the "lvs" command if you're unsure.

Kind regards,
Bryn.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org

iD8DBQFGUb5n6YSQoMYUY94RAomyAKDAbKh46jVdf/rnfjPrx8deodF4tQCZAWJj
aBE96ivGnSiu1/X1lNX4QIM=
=Tvod
-----END PGP SIGNATURE-----

Re: [linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table

[Sean McGlynn]

[-- Attachment #1: Type: text/plain, Size: 1626 bytes --]

I see.  I thought it was physical disks.  Yes, I have four logical volumes.

Thank you again for all your help.


----- Original Message ----
From: Bryn M. Reeves <breeves@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>
Sent: Monday, May 21, 2007 11:44:39 AM
Subject: Re: [linux-lvm] Disk /dev/dm-0 doesn't contain a valid partition table


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Sean McGlynn wrote:
> Bryn,
>  
> Thank you for taking the time to reply.
>  
> I'm glad to see this is not an issue. 
>  
> As for "dev253," if I only have three physical devices, why four dm entries?
>  
> Thanks again.
> 

The "dev253" entries are the logical volumes (or other device-mapper
devices), not the physical devices themselves.

I see you have three PVs in the volume group (sda1, sdb2 & sdc1), but
how many LVs do you have in your volume group?

Just post the output of the "lvs" command if you're unsure.

Kind regards,
Bryn.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org

iD8DBQFGUb5n6YSQoMYUY94RAomyAKDAbKh46jVdf/rnfjPrx8deodF4tQCZAWJj
aBE96ivGnSiu1/X1lNX4QIM=
=Tvod
-----END PGP SIGNATURE-----

_______________________________________________
linux-lvm mailing list
linux-lvm@redhat.com
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/


 
____________________________________________________________________________________
Get your own web address.  
Have a HUGE year through Yahoo! Small Business.
http://smallbusiness.yahoo.com/domains/?p=BESTDEAL

[-- Attachment #2: Type: text/html, Size: 2821 bytes --]