The OpenStack Summit this week continued to fan the flames of the software-defined data center. The software-defined data center is just a term for replacing traditional data center hardware functionality with the same features implemented in software, running on commodity x86 servers. While software-defined approaches to data center features are at least nominally less expensive than their hardware counterparts the real promise in the approach is flexibility and management ease with high levels of integration. Reconfiguring a network to support the security requirements of a new application is now just a function of software and APIs. Expanding storage is just simply adding another node with more storage attached, and the cluster compensates automatically. Even things like firewall rules and load balancer configurations can now be stored as templates along with the applications, to be provisioned in minutes.
Articles Tagged with ESXi
I recently had the joys of helping deal with an All Paths Down (APD) situation which presented itself when removing a LUN from all the hosts in a cluster. If you do not detach the device first, which will also initiate an unmount operation before you physically unpresent the LUN from the ESX, it causes an APD situation to happen. ADP is when ESXi server no longer has any active paths to a device. When the device is no longer present and you rescan the adapters ESXi server will still retain the information on the removed devices and hostd will continue to try to open a connection to the disk device by issuing different commands like read capacity and read requests to validate the partitions tables are set. If SCSI Sense codes are not returned from a device (you are unable to contact the storage array, or the storage array that does not return the supported “SCSI codes”), then the device is in an All-Paths-Down (APD) state, and the ESXi host continues to send I/O requests until it times out.
At the NE VMUG, while walking the floor I saw a new virtualization backup player, perhaps the first generic Replication Receiver Cloud: TwinStrata. And information gained while not at the NE VMUG. There is also a new virtualization backup player just for Hyper-V: Altaro. As well as a new release of Quest vRangerPro. The Virtualization Backup market is a very dynamic market with new ideas, technologies, and concepts being put into the market at every turn. In many ways, the market leaders are not the bigger companies but the smaller and fast growing companies. In the past, it was about features associated with pure backup, but now it is about features and fast disaster recovery and recovery testing.
With the announcement of vSphere 5.0, VMware has kept its word on only having VMware ESXi for the physical host operating system. This is the first release of vSphere with just VMware ESXi as an option. I must admit that I was not a big fan of the concept when it was introduced as an option in the 3.x days. I had a very slick automated process in place that was one of my pride and joys at the moment and VMware ESXi was just lagging behind in functionality compared to what I was able to do with VMware ESX. My attitude started to change with the release of VMware ESX 4.1 as presented in an earlier post and now that vSphere 5.0 is announced I must admit that I think VMware has gone about this process of a cutover to ESXi quite well and the functionality that is presented in this release is quite impressive.
In my last post I talked about how to resolve an issue where a disgruntled employee walked out with the USB memory stick that had VMware ESXi installed on it. In that particular case, the VMware ESXi host kept on running and I was able to get a backup and restore the current running configuration via some PowerShell magic. All in all it was a pretty easy issue to resolve with very little down time. This got me thinking about which method would be the best option to use in the Enterprise. Installing to local disks or installing to a USB memory stick.
Each method has its own pros and cons that should be considered when designing your deployment. Let’s look at each method and present a few options:
I got a call from a client today that is running a VMware ESXi server as a proof of concept in their SMB environment. The admin that setup the VMware ESXi Server configured the ESXi server to boot and run ESXi from a USB memory stick. Things have been running fine but the company and the administrator that setup the server had a falling out, so to speak, and the administrator left the company and took the USB memory stick with him. The server continues to run fine as ESXi basically runs from memory but, rebooting this host is now not an option since there are no files available for the host to boot from. So what is the best way to recover and get things back to normal? I did a little research and the information that I have found will work will both ESXi 3.x as well as vSphere ESXi.