SteWeBe
Contributor
Contributor

"Unable to read partition information from this disk"

On ESX Server 3.01 I can see a 400GB SAN LUN through the fibre channel hbas. When I try to use that storage by "Add Storage" i choose Disk/Lun, then i see the 400GB device, choose it, click next and get this:

"Unable to read partition information from this disk"

In another enty on the board I found a hint about using fdisk and creating a partition table. Did that, can access the LUN with fdisk. But still have the same problem when i try to make it available to ESX Server.

Can anybody help?

Thanks!

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8 Replies
swamy
Enthusiast
Enthusiast

i got an error similar to this

then wat i actually did is

#fdisk /dev/lunidentifier

comand (m for help) : n

comand (m for help) : w

#partporbe

#fdisk /dev/lunidentifier

comand (m for help) : d

comand (m for help) : w

#partprobe

now i am able to add this lun through vi client

and then i formatted it with vmfs3

i know the suggestion wat i gave is not worth but giv it a shot

Message was edited by:

swamy

christianZ
Champion
Champion

SteWeBe
Contributor
Contributor

Thanks everybody for leading me in the right direction.

For me the following steps worked:

1. using fdisk to create a new partition with the full available space on the LUN and to mark it as unknown[/b]

Here is how to create a single primary partition which takes up all the disk, changing the type to 0xfb:

\# fdisk /dev/sdf

Command (m for help): p

Disk /dev/sdf: 140 heads, 62 sectors, 1018 cylinders

Units = cylinders of 8680 * 512 bytes

Device Boot Start End Blocks Id System

Command (m for help): n

Command action

e extended

p primary partition (1-4)

p

Partition number (1-4): 1

First cylinder (1-1018, default 1):

Using default value 1

Last cylinder or +size or +sizeM or +sizeK (1-1018, default 1018):

Using default value 1018

Command (m for help): t

Partition number (1-4): 1

Hex code (type L to list codes): fb

Changed system type of partition 1 to fb (Unknown)

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

Run fdisk -l option to review your partition table.

\# fdisk -l /dev/sdf

Disk /dev/sdf: 140 heads, 62 sectors, 1018 cylinders

Units = cylinders of 8680 * 512 bytes

Device Boot Start End Blocks Id System

/dev/sdf1 1 1018 4418089 fb Unknown

2. creating a new vmfs using vmkfstools[/b]

vmkfstools -C vmfs3 -b 1m -S myVMFS /vmfs/devices/disks/vmhba1:0:17:1

IMPORTANT: vmkfstools only worked fine when VI Client was closed. Otherwise vmkfstools could not write to the LUN![/b]

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Dave_M
Contributor
Contributor

Great answer to a strange problem, assigned 9 1TB LUNs to the 6 ESX Servers in a cluster. I could create vmfs datastores on 8 of them, but 1 of them had this error.

But now it is fixed - thanks - make me look like the guru in my customer's eyes.

Regards

Dave

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mkats
Contributor
Contributor

Thanks for all the help. VMKFSTOOLS did not work but fdisk o did. Ran fdisk /vmfs/devices/disks/vmhbaW:X:Y:Z:0

Command (m for help): o

Building a new DOS disklabel. Changes will remain in memory only,

until you decide to write them. After that, of course, the previous

content won't be recoverable.

Went back into VI Client -> Add Storage -> saw the lun and available capacity.

Hope this helps -Mike

Happened again but this it looks like the LUN was not visible because it could not see a partion table.

Ran fdisk vmhba:W:X:Y:Z:0

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

Message was edited by: mkats

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admin
Immortal
Immortal

Very helpful

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SINTM
Contributor
Contributor

Hello,

I actually have the same problem with ESX 3.5 and an EMC CX3-10 SAN.

We add recently a new SATA2 disk rack with 6 disks, create the Raid group, the LUN and add it to the Storage Group.

When scanning hbas on VIclient, I can see the LUN but when I try to add it in Storage, I have the same message "unable to read partition info..."

After reading this post and some others on this subject, I create a VMFS partition with fdisk but nothing changes.

What I didn't try is the VMKFSTOOLS because I can't understand on which disk I have to do this : when I type ls /vmfs/devices/disks/ there is a lot of hbas with this format hbax:x:x:x whil the canonical name of the LUN I try to add is hbax:x:x

I don't want to format a LUN already in use, so if you have an idea about the disk I have to format, any suggestion is welcome.

Thanks by advance

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juchestyle
Commander
Commander

These are my notes on the subject:

Unable to read partition information from this disk

Can't have a partition outside the disk

Error

Step 1: Identify the lun:

  1. From cl: esxcfg-mpath -l (L)

  2. Look for the lun in question, as a helpful hint use the add storage wizard from the vmware client to identify as much information as possible. Vmhba1:2:97 for example will help you find the Lun in question and this can be found from the client. Also verify in the client on the cl the SAN Identifier: 50:06:04:82:d5:2d:7e:27 for example. Match these two things up to find the /dev/sdby for example in the cl.

Step 2: Make a msdos label

  1. From the command line: parted /dev/sdby

  2. Type print to see information about this lun before you wipe it out

  3. This next step will wipe out the lun make sure you have the right one

  4. Mklabel msdos

  5. Quit to exit and you should be able to add the storage in the client gui now

Kaizen!

Kaizen!
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