Fatal Error while trying to detect swap signature

Question

I've installed CentOS 6.5 On VMWare Workstation. I added a SCSI Virtual Disk (.vmdk) to this Machine when it was Powered On. I decided to store the Disk as a single file & allocated all disk space at once.

I try to run pvcreate /dev/sdb & I get the following error message.

[root@localhost dev]# pvcreate /dev/sdb
  /dev/sdb: read failed after 0 of 4096 at 0: Input/output error
  /dev/sdb: read failed after 0 of 4096 at 21474770944: Input/output error
  /dev/sdb: read failed after 0 of 4096 at 21474828288: Input/output error
  /dev/sdb: read failed after 0 of 4096 at 4096: Input/output error
  Fatal error while trying to detect swap signature on /dev/sdb.

I've looked up this error on Google but got nowhere with the first few search results. Can someone please help me out with this ?

Answer 1

your Virtual disk is not in active state, Once you rebooted its came to active state.

Answer 2

I was able to solve the issue with a reboot of the Virutal Machine. After reboot, I was able to run

pvcreate /dev/sdb successfully.

Any idea what happened after a reboot. I'd like to know more on why a reboot resolved the issue.