Change extended partition id

Solution Unverified - Updated -

Environment

  • Red Hat Enterprise Linux (RHEL)

Issue

  • We are currently seeing the following (below) when doing an fdisk -l on one of our servers. We see a partition that has a label f which is W95 Ext'd (LBA). We noticed that this partition /dev/sda4 seems to have the same start as /dev/sda5 and the same end as /dev/sda7 which are both Linux LVM partitions. After doing df, pvs, fdisk -l, blkid, etc we don't see where the /dev/sda4 partition is being used so we are wondering if this can be removed or relabeled?? Currently this is causing issues with our backups since this label is not supported.
Disk /dev/sda: 68.7 GB, 68719476736 bytes
255 heads, 63 sectors/track, 8354 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        1798    14338012+  83  Linux
/dev/sda3            1799        2320     4192965   82  Linux swap / Solaris
/dev/sda4            2321        7148    38780910    f  W95 Ext'd (LBA)
/dev/sda5            2321        3748    11470378+  8e  Linux LVM
/dev/sda6            3749        5189    11574801   8e  Linux LVM
/dev/sda7            5190        7148    15735636   8e  Linux LVM

Resolution

Unfortunately there is no way to achieve same without re-creating partitions.

What you can do is, attach new disk and copy all data from these partitions to that new disk. After this, delete this extended partition and re-create it with same starting and end cylinder.

Root Cause

/dev/sda4 is extended partition and other partitions (sda5-sda7) are logical partitions.

I tried to change extended partition type but its not allowed :


# fdisk /dev/loop0 
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help): p

Disk /dev/loop0: 209 MB, 209715200 bytes, 409600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x3f8862cf

      Device Boot      Start         End      Blocks   Id  System
/dev/loop0p1            2048       22527       10240   83  Linux
/dev/loop0p2           22528      409599      193536    5  Extended

Command (m for help): t
Partition number (1,2, default 2): 
Hex code (type L to list all codes): f

You cannot change a partition into an extended one or vice versa.
Delete it first.

Type of partition 2 is unchanged: Extended

Command (m for help):

If you want to change extended partition id from "W95 Ext'd (LBA)" then its not possible. Only way is to re-create it.

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