Assuming this is not a server internal disk.
Please check the following:
- is there a read only lun allocation from storage perspective?
- is there a disk read only attribute on OS level?
OS read only attribute example:
C:\Users\Administrator> diskpart
Microsoft DiskPart version 6.0.6002 Copyright (C) 1999-2007 Microsoft Corporation. On computer: COMPUTERNAME
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt -------- ---------- ------- ------- --- --- Disk 0 Online 64 GB 0 B Disk 1 Online 78 GB 2048 KB
DISKPART> select disk 1
Disk 1 is now the selected disk.
DISKPART> detail disk
Disk Device Disk ID: 02872505 Type : iSCSI Bus : 0 Target : 0 LUN ID : 0 Read-only : Yes <--- Make sure of read-only mode Boot Disk : No Pagefile Disk : No Hibernation File Disk : No Crashdump Disk : No
There are no volumes.
DISKPART> attribute disk clear readonly
Disk attributes cleared successfully.