Looking for a Root cause?

[pravin_utekar12]

HI Techies,

I come across the situation where one of shared lun goes offline and due to which all the host on the vcenter started disconnecting one by one?

I an not able to find the cause for this please assist  if any one have faced such issue.

[a_p_]

The most straight forward way to troubleshoot is checking the log files. This could e.g. be caused by an issue with the storage system (less likely) or maybe by a Windows host with access to the LUN. If a Windows system with "Automount" enabled has write access to a VMFS LUN it may change the partition type to NTFS. Depending on the ESXi/VMFS version you are using, you may use either fdisk or partedUtil to check the VMFS datastores.

André

[pravin_utekar12]

Hi a.p, Thanks for reply...

My concern is when the lun goes offline after some time host from vcenter started getting disconnected from vcenter and vice versa when lun comes online host connected automatically.

I want to know what is connection between host disconnection and lun offline.

Thanks

[Sundararajan]

The cause might me your ESXi is installed on the lun..

[a_p_]

Ok, so the LUN comes back automatically!?

Which ESX/ESXi version/build do you use? If you are running an older version without the latest patches, the missing LUN may cause an APD (All Paths Down) condition on the host. Do you see any errors/messages in the host's vmkernel logs?

André