ESXi

The Host Virtual MAC Address Riddle

September 5, 2016 Bilal Ahmed 1

For ages I have been pondering over ‘something’ which seems very trivial and the fact I can’t get any solid info on it is driving me nuts: Why does every pNIC also have a virtual MAC address? So here with have the VMkernel ports, a VSS and pNICS: Just as you would expect, every physical NIC (pNIC) on a host has a MAC address. BUT when you type ‘esxcfg-info -n‘ in the shell, you will notice that every vmnic also has a Virtual MAC Address!   \==+Physical Nic : |—-Name…………………………………………..vmnic3 |—-PCI Segment…………………………………….0 |—-PCI Bus………………………………………..2 |—-PCI Slot……………………………………….0 |—-PCI function……………………………………1 |—-MAC Address…………………………………….XX:XX:XX:32:06:1f |—-Virtual MAC Address……………………………..00:50:56:52:06:1f |—-FPT Shareable………………………………..true Now as you can see the Virtual MAC Address starts off with a VMware MAC and then finishes at the […]

Dell Compellent and SCSI UNMAP

May 15, 2016 Bilal Ahmed 0

Dead space reclamation (SCSI UNMAP) Basically the UNMAP command is used when you have Thin Provisioned LUNs, you run it against VMFS  5 datastores, hopefully freeing up some space. This will allow the hosts to correctly report the list of deleted blocks on the datastore to the array. It basically is a space reclamation feature that helps reclaim space left by deleted data. The main reasons you would want to run this on all Thin Provisioned LUNs, would be because of: Storage vMotion, VM snapshots and VM deletion. As even though the VM/Snapshot etc has been deleted it doesn’t mean the array is aware of this! It was disabled in ESXi 5.0, due to various issues and enabled in 5.1 by using […]

Setting a persistant scratch location on a ESXi host

May 11, 2016 Bilal Ahmed 0

I noticed one of the hosts had a warning saying that: So basically I did what this KB article said: VMware KB article I had a look at another host, and had a look at the Advanced Settings value for: ScratchConfig.ConfiguredScratchLocation It showed a VMFS volumes /vmfs/volumes/UUID/Scratch folder for that host. So it showed me the UUID such as this: vmfs/volumes/51dda02d-fade5016-8a08-005056171889/HOSTNAME So it looked like there was a folder on this LUN every host! So since I am new to this environment I had to find a way to translate the UUID to the name of the actual SAN datastore being used. I did this by using the: esxcli storage filesystyem list | grep UUID This gave me the actual […]