The VMguy

vSphere Replication and Site Recovery Manager make it very easy to replicate your VMs to your DR site (ahem, once they are set up).  Some customers asked me if there is any way to throttle the bandwidth used for replication.  The good news is that there is a way in vMware software but it cannot be found in SRM.  Unfortunately, it can only be found in the Enterprise Plus Edition of vSphere 5.  It’s Network I/O Control in the Distributed vSwitch (DvS) in v5.  I’m not going to go into a deep dive on Network I/O Control but I will recommend that you read the Network I/O Control best practices doc here.

To enable Network I/O Control we need to have a DvS in place.  If we select the distributed switch and then select the Resource Application tab on the right, this gives us the “properties” option on the far right.  By selecting the Properties option, you can enable Network I/O Control on the DvS.  Once enabled you can see all of the System network resource pools.  There is one at the bottom of the list labeled “vSphere Replication (VR) Traffic”.  Selecting it and then clicking the “Edit Settings” link just below it opens up the settings window.

From here, you can edit the adapter shares.  The shares are to balance the bandwidth so that network flows can use the bandwidth thats available from a given dvuplink.  The shares are for a given dvUplink.

Alternatively, you can uncheck the Unlimited checkbox and set a host limit.  Keep in mind that this is Megabits per sec, not MegaBytes.  This is also the limit of the combined set of dvUplinks on a given host.

Lastly, a QOS priority tag can be used.  The traffic will have a 802.1p tag applied to it.  The IEEE does not standardize or mandate the use of the priority tag applied to the packets but the switches should treat higher tags with higher priority.  The choices are None, 1-7.

While not the granular controls that we may wish for, say individual bandwidth controls on a per VM or per-site replication limits, these settings and options are a start.  Hopefully in the future in vSphere Replication v2 we will have more granular controls for bandwidth throttling but until then, these are what we can use.  Happy computing.

VMware saw an issue with the SMB customers in that some were not adopting the higher editions of their software because most of the features required shared storage and some SMBs might not have been ready to bite off the costs of that storage.  So VMware decided to get creative and create a redundant shared storage solution using local storage.

Here are some of the features:

• Deploys as an appliance, very easy to install
• Must be deployed on a new ESXi 5.0 installation
• Deploys a VSA Cluster Service on the vCenter server
• The VSA Cluster Service can deploy the VSA “Agent VMs” to each of the ESXi 5.0 hosts
• The appliance will use the local space available and present the storage on the network as an NFS datastore
• Replicates the local storage to the local storage on another host in the cluster for redundancy.
• If a host fails, the appliance storing the replica will immediately take over the failed “Agent VM’s” IP address and share the storage from the replica
• v1.0 supports 2 or 3 ESXi hosts in a cluster (Typically for the essentials kits)
• Sold as a separate SKU with one price with no license capacity restrictions (no technical size limits that I could find)
• Supports 25 VMs (configured on 2 ESXi hosts) or 35 VMs (configured on 3 ESXi hosts)
• It is the only scenario where VMware recommends running vCenter on a physical or standalone ESXi hypervisor (To protect you from running into a Catch-22 as vCenter is managing the VSAs
• Recommended to use RAID10 on the hardware RAID controllers in the hosts (to protect from a single drive failure)
• Uses RAID 1 (Mirroring) between hosts for redundancy
• Supports Storage vMotion for when you are ready to migrate to hardware shared storage
• Can put the whole VSA cluster in maintenance mode or just a single node.  Can also replace a node and have the VSA rebuild onto it for redundancy or for rolling upgrades.

Here’s how it works: Imagine I have 3 hosts numbered 1,2 and 3.  Once the VSA gets installed, it creates two volumes on the available local storage on each host.  So host 1 will have volumes 1A and 1B, host 2 has 2A and 2B, host 3 has 3A and 3B.  Once the VSAs are configured, they will be redundant so that 1A (which stores VMs) mirrors to 2B, 2A mirrors to 3B and 3A mirrors to 1B.  If any VSA get’s dropped, the VSA running the mirror copy takes the IP address of the failed VSA and keeps right on chugging.

My Take

The Pros: Great solution for SMBs without shared storage to take advantage of HA, vMotion, etc.  I also think this is an outstanding solution for companies with remote offices who want to have redundancy in 2 or 3 ESXi hosts but don’t want to put shared storage in each site.

The Cons:  Way too much overhead.  VMware is recommending hardware RAID10 from the local drives if possible.  If I have 4 x 1TB drives in a server (4TB RAW disk capacity).  I use RAID10 as per VMware’s recommendation, this means 2TB gets presented to the ESXi host.  Now the VSA uses half of that storage for VMs and half as a target to mirror the VSA from one of the other hosts.  So out of 4TB of RAW disk, I get <1TB of capacity to store VMs on (don’t forget, I need room to store ESXi itself).  Thats a 75% reduction from RAW capacity = too much overhead.

Overall I still think it’s worth it.  It’s still going to be less expensive that a shared storage frame (even with the overhead loss).  I think for remote sites, you can’t beat it.  I can’t wait to see what they add to it in v2.0.

As I was wading thru all of the new materials from yesterday, I thought it would be helpful to create a big list of all of the new features in vSphere 5.0.  There were really only a few named in the presentation (or else the preso would have been 3 hours and put the analysts to sleep).  While we wait for the release notes, I put together this list for you.  This is not every new feature, but rather as many as I could find or remember.  I’ve also added a quick blurb on what that feature does and my comments in parenthesis.  If you are aware of something that I missed, please add in the comments below (with your own comments/opinions of course).  Here we go:

VMware vSphere 5.0

• ESXi Convergence – No more ESX, only ESXi (they said they would do it, they meant it)
• New VM Hardware:  Version 8 – New Hardware support (VS5 still supports VM Hardware 4 & 7 as well if you still want to migrate to the old hosts)
  • 3D graphics Support for Windows Aero
  • Support for USB 3.0 devices

• Platform Enhancements (Blue Requires Hardware v8)
  • 32 vCPUs per VM
  • 1TB of RAM per VM
  • 3D Graphics Support
  • Client-connected USB devices
  • USB 3.0 Devices
  • Smart-card Readers for VM Console Access
  • EFI BIOS
  • UI for Multi-core vCPUs
  • VM BIOS boot order config API and PowerCLI Interface
• vSphere Auto Deploy – mechanism for having hosts deploy quickly when needed ( I’m going to wait and see how customers use this one.)
• Support for Apple Products – Support for running OSX 10.6 Server (Snow Leopard) on Apple Xserve hardware. (although I betting technically, you can get it to run on any hardware, you will just not be compliant in your license) Read the rest of this entry »

One of the greatest things VMware ever did in vSphere was add the Storage Views tab.  Storage views let’s you see detailed information on the size of your VMs, how much space each VM takes up in snaps, etc.  One question I very often get asked is:  “How do I export that information from Storage Views to excel or CSV?  The answer is simple, but it’s probably not where you have been looking.

Let’s go thru an example.  First things first, before you export, make sure you have all the information you need.  In the vSphere client, pick your level to look at the Storage View (the vCenter Server, the datacenter, a cluster, a host, etc) and select the Storage Views tab on the right.  Right-click the title bar in the right pane and make sure you have all of the fields you need.  The menu will look something like this one here:

Make sure you select all of the columns of data that you want (or don’t want).  Once you have that cleaned up, we go for the export.  Your instinct would be to go to File and Export like this:

Notice how the Export List option is greyed out?  That’s where you would expect to find the export function for the Storage Views.  I think there is a bug in the interface as that is not really where it is located in this case.  For Storage Views, move the cursor to some white space on the right or the bottom of the right pane and right-click.  You should see a popup menu that looks like something like this:

Select “Export List” from the menu and you can save the storage view as Excel, HTML, CSV, etc.  There, now you have some great data for graphs or whatever you like.

One more tip:  If you export the fields to Excel, the cells will all be text and the data values will have “GB” in the cells with them.  If you want to remove the “GB” and convert to numeric so you can work with the values here’s how:

Let’s say Cell C3  has a value of “7.77 GB”.  Create a new column and for the value put in  =VALUE(LEFT(C3,LEN(C3)-3))

The LEFT() function will cutoff the “GB” and the VALUE() function will convert the TEXT to a numeric value that you can add, subtract, etc.

Now you can add a cell at the bottom and use the AVERAGE() function and find out what your average VM size really is!  Or SUM() the Snapshot column and find out how much space your VM snaps are taking up on storage.  There are all kinds of options, have fun and enjoy!

Hopefully this issue will get fixed soon.  I was working on a new deployment for a customer when I noticed this issue.  The issue is this:  I created a few windows VMs for this customer to use as templates.  I created them as thick, figuring I would patch, defrag, shrink, then convert to thin.  When I did, I noticed that my disks went from 50GB to 49.9GB, huh?  Looking inside the VM, the C drive was using 8GB of space.  Where was this 49.9GB coming from?  After a bit of searching on the net, I came across this thread in the communities. I looked thru the article and sure enough the listed fix works.  I had a extra LUN for this customer that had not been used yet.  I deleted the datastore and created a new one with a different block size as the others.  I tried the svmotion with converting to thin again and this time, Bingo, 8GB as expected.  I was then able to svmotion back to my original LUN telling the svmotion to keep the same type.  Worked great and stayed 8GB.

Duncan wrote an explanation in the community thread for what is going on:

“It most definitely has to do with the type of datamover used. When a different blocksize is used for the destination the legacy datamover is used which is the FSDM. When the blocksize is equal the new datamover is used which is FS3DM. FS3DM decides if is will use VAAI or just the software component, in either case unfortunately the zeroes will not be gobbled. I have validated it and reported it to engineering that this is desireable. The team will look into it but unfortunately I cannot make any promises if or when this feature would be added.”

It sounds to me like if your storage supports VAAI and ESXi offloads the svmotion to it, there’s no hope of shrinking because VAAI is not that intelligent.  When you svmotion between two different LUN block sizes (or between iSCSI, NFS or FC) it uses old-school svmotion (probably because the VMFS block layout changes) which will actually convert the VM to thin when it moves.

Hopefully VMware engineering will change svmotion to automatically use old-school svmotion when you select to change from thick or thin and only use VAAI when you choose to keep the same format during the move.  We’ll have to wait and see….