Linux operating system completely clear error disk/dev/mapper/ddf1_4c53492 ....

Description of the phenomenon

disk/dev/mapper/ddf1_4c5349202020202010000055000000004711471100000a28p1:666.0 GB, 666000889344 bytes

255 heads, Sectors/track, 80969 cylinders

Units = Cylinders of 16065 * 8225280 bytes

Sector size (logical/physical): bytes/512 bytes

I/O size (minimum/optimal): bytes/512 bytes

Disk identifier:0x00000000

Disk/dev/mapper/ddf1_4c5349202020202010000055000000004711471100000a28p1 doesn ' t contain a valid partition table

Reason:

This is because the hard disk has raid information, and when the second-hand drive is plugged into the server, the system automatically discovers the raid based on the remaining information (which we do not want to happen).

And the hard disk can not be formatted, the format will be error, the hard disk is being used.

How to solve this problem, try some methods, finally solved the problem with dmraid.

Due to the automatic recognition of the system, the hard disk is built into a raid (even if there is no real raid), which is why the report is being used and cannot be formatted.

Let's use Dmraid to disable the active state.

1:

[Email protected] ~]# dmraid-a no

ERROR:ddf1:wrong # of devices in RAID set "Ddf1_4c5349202020202010000055000000004711471100000a28" [On/dev/sdb]

RAID Set "Ddf1_4c5349202020202010000055000000004711471100000a28" is not active

RAID Set "Ddf1_4c5349202020202010000055000000004711471100000a28" is not active

Dmraid–a no command is to cancel the active state, the first line of error do not tube, it is said/dev/sdb only 1/2raid information, information is not complete,

This also lets us know which disk has the raid information, of course, you can directly change the SDB to a clean plate is also possible.

You can see from the latter two sentences that the RAID array is not active.

2. Next use Dmraid–x to clear the raid information

[Email protected] ~]# dmraid-x

ERROR:ddf1:wrong # of devices in RAID set "Ddf1_4c5349202020202010000055000000004711471100000a28" [On/dev/sdb]

About to delete RAID set ddf1_4c5349202020202010000055000000004711471100000a28

Warning:the metadata stored on the Raidset (s) is not being accessible after deletion

Want to continue? [y/n]:

Select Y

Error:raid set deletion is not supported in "DDF1" format

Display error, but still deleted,fdisk–l no RAID information

The partition is then deleted and rebuilt, the format succeeds, and the load is successfully mounted.

Linux operating system completely clear error disk/dev/mapper/ddf1_4c53492 ....