vSAN and Data-At-Rest Encryption – Why SED’s are not Supported (i.e. Part 3)

I first wrote about vSAN and Encryption here: Virtual SAN and Data-At-Rest Encryption

And then again here: vSAN and Data-At-Rest Encryption – Rebooted (i.e. Part 2)

And then vSAN Encryption went live in vSAN 6.6 announced here: vSAN 6.6 – Native Data-at-Rest Encryption

Today I was asked if vSAN supports Self Encrypting Drives (SED). The answer is No. The vSAN product team looked at SEDs but there are too few choices, they are too expensive, and they increase the operational burden.

vSAN only supports vSAN Encryption, VM Encryption, or other 3rd party VM encryption solutions like HyTrust DataControl.

vSAN is Software Defined Storage so the product team decided to focus on software-based encryption to allow vSAN to support data at rest encryption (D@RE) on any storage device that exists today or will come in the future. When vSAN went live supporting Intel Optane, this new flash device was immediately capable of D@RE. The vSAN Encryption operational model is simple. Just click a check box to enable it on the vSAN datastore and point to a Key Management Server. One encryption key to manage for the entire vSAN datastore. The additional benefits of vSAN Encryption is that it supports vSAN Dedupe and Compression and vSAN 6.7 encryption has achieved FIPS 140-2 validation.

Another choice is to leverage VMware’s VM Encryption described here: What’s new in vSphere 6.5: Security
This is per VM encryption, so you point vCenter to a Key Management Server and then enable encryption per VM via policy. This flexibility allows some VM’s to be encrypted and some not to be. And, if the VM is migrated to another vSphere cluster or to VMware Cloud on AWS, the encryption and key management follows the VM. This requires the administrator to manage a key per VM, and because the encryption happens immediately as the write leaves the VM and goes through the VAIO filter, no storage system will be able to dedupe the VM’s data since each block is unique.

Finally, there are various 3rd party per VM encryption solutions on the market that vSAN would also support. For instance, HyTrust Datacontrol.

I hope this helps clear up what options there are for vSAN encryption and the various tradeoffs.

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vSphere 6.7 and vSAN 6.7 in the News

Yesterday was a big day for vSphere and vSAN with the launch of the 6.7 release. There are many great blogs written so rather than repeat the content, here’s a list with links.

VMware Written Content

VMware Web Site: What’s New: vSAN 6.7
VMware Virtual Blocks: Extending Hybrid Cloud Leadership with vSAN 6.7
VMware Virtual Blocks: What’s New with VMware vSAN 6.7
VMware Virtual Blocks: vSpeaking Podcast Episode 75: What’s New in vSAN 6.7
Yellow-Bricks.com: vSphere 6.7 announced!
CormacHogan.com: What’s in the vSphere and vSAN 6.7 release?
Tohuw.Net: The Art in the Architecture – vSAN & Shared Nothing

Industry Analyst Content

 

VMworld Hands-on-Labs – 9,640 Labs Were delivered by vSAN

The Hands-on-Labs (HoL) at VMworld are always a big hit. A ton of work goes into putting them on and supporting them and everyone seems to love them. This was a big year for vSAN in the HoL. At VMworld Las Vegas, 11,444 labs were completed and the vSAN lab, HOL-1808-01-HCI – vSAN 6.6, was the #2 overall lab completed. Our NSX friends held the #1 spot.

The HoL’s were delivered from 5 different data centers. Each handled approximately 20% of the workloads. vSAN was the storage in 4 of the data centers. 2 of the 4 were VMware data centers running vSphere, NSX, and vSAN for software defined compute, network and storage. Another was IBM BlueMix (SoftLayer) built with VMware Cloud Foundation (vSphere, NSX, vSAN, and SDDC Manager). And the other was VMware Cloud on ASW also built with VMware Cloud Foundation (vSphere, NSX, vSAN, and SDDC Manager). The 5th data center was another VMware data center running traditional storage. This is a great Hybrid Cloud / Multi Cloud example leveraging 3 of our own datacenters and 2 of the largest public cloud data centers offering Infrastructure as a Service (Iaas).

 

VMware Cross Cloud Architecture

 

9,640 of the HoL’s were deployed across the 4 vSAN data centers. This represents 84% of the labs delivered at VMworld US were delivered by vSAN. To support the HoL’s, over 90,000 VM’s were provisioned in just 5 days. Actually, more than that since extra HoL’s are pre-provision that don’t all get used. This is a huge win for HCI and vSAN as it performed like a champ for this heavy workload.

These stats are too impressive not to share and they are a great testament to all the people that make it happen.

 

 

 

 

 

vSAN IP Networking Versus Fibre Channel

Today I was asked by a customer: “By taking all of our storage traffic off of our Fibre Channel network and putting it onto our IP network, won’t that cause major network congestion?”

Quick answer is no if you implement some form of traffic “Isolation”. There are many ways to achieve isolation of vSAN traffic. All of them are identical to how you would isolate NAS or iSCSI storage traffic.

vSAN traffic can be isolated using dedicate physical switches. But most customers implementations leverage existing core switches that support all other IP traffic. In this case, for vSAN, the strong recommendation is to create a dedicated VLAN for the vSAN traffic.

On the host side, you can dedicate physical NIC’s for vSAN traffic. Some customers do this but others find that shared physical 10GbE NICs (2 for redundancy) on hosts provides enough bandwidth. When doing this, it is recommend to implement vSphere Distributed Switches and then configure vSphere NIOC to allocate bandwidth shares for different vSphere traffic. Typically vSAN should be allocated 50% of the shares.

There is an updated networking design guide for more details on all of this here:

VMware® Virtual SAN™ Design and Sizing Guide 

vSAN Maintenance Mode Considerations

There are 3 options when putting a host in maintenance mode when that host is a member of a vSphere Cluster with vSAN enabled.  You follow the normal process to put a host in maintenance mode, but if vSAN is enabled, these options will pop up:

  1. Ensure accessibility
  2. Full data migration
  3. No data migration

There’s a 4th consideration that I’ll describe at the end.

I would expect most virtualization administrators to pick “Ensure accessibility” almost every time.

Ensure accessibility

Before we investigate, I want to reinforce that vSAN, by default, is designed to work and continue to provide VM’s access to data even if a host disappears.  The default vSAN policy is “Number of Failures To Tolerate” equal to 1 (#FTT=1), which means a HDD, SSD, or whole host (thus all the SSD and HDD on that host) can be unavailable, and data is available somewhere else on another host in the cluster.  If a host is in maintenance mode, then it is down, but vSAN by default has another copy of the data on another host.

VMware documents the options here:

Place a Member of Virtual SAN Cluster in Maintenance Mode

Ensure accessibility

This option will check to make sure that putting the particular host in maintenance mode will not take away the only data copy of any VM.  There are two scenarios I can think of that this would happen:

  • In Storage Policy Based Management, you created a Storage Policy based on vSAN with #FTT=0 and attached at least 1 VM to that policy and that VM has data on the host going into maintenance mode.
  • Somewhere in the cluster you have failed drives or hosts and vSAN self-healing rebuilds haven’t completed. You then put a host into maintenance mode and that host has the only good copy of data remaining.

As rare as these scenarios are, they are possible.  By choosing the “Ensure accessibility” option, vSAN will find the single copies of data on that host and regenerate them on other hosts. Now when the host goes into maintenance mode, all VM data is available.  This is not a full migration of all the data off that host, its just a migration of the necessary data to “ensure accessibility” by all the VM’s in the cluster.  When the host goes into maintenance mode, it may take a little bit of time to complete the migration but you’ll know that VM’s won’t be impacted.  During the maintenance of this host, some VM’s will likely be running in a degraded state with 1 less copy that the policy specifies.  Personally, I think this choice makes the most sense most of the time, it is the default selection, and I expect vSphere administrators to choose this option almost every time.

No data migration

This option puts the host in maintenance mode no matter what’s going on in the cluster.  I would expect virtualization administrators to almost never pick this option unless:

  • You know the cluster is completely healthy (no disk or host failures anywhere else)
  • The VM’s that would be impacted aren’t critical.
  • All the VM’s in the cluster are powered off.

For the reasons explained in the “Ensure accessibility” above, its possible that the host going into maintenance mode has the only good copy of the data.  If this is not a problem, then choose this option for the fastest way to put a host into maintenance mode.  Otherwise, choose “Ensure accessibility”.

Full data migration

I would expect virtualization administrators to choose this option less frequently than “Ensure Accessibility” but will choose it for a couple of reasons:

  • The host is being replaced by a new one.
  • The host will be down for a long time, longer than the normal maintenance window of applying a patch and rebooting.
  • You want to maintain the #FTT availability for all VM’s during the maintenance window

Keep in mind, if you choose this option you must have 4 or more hosts in your cluster, and you don’t mind waiting for the data migration to complete.  The time to complete the data migration is dependent on the amount of capacity consumed on the host going into maintenance mode.  Yes, this could take some time.  The laws of physics apply.  10GbE helps to move more data in the same amount of time. And it helps if the overall environment is not too busy.

When the migration is complete, the host is essentially evacuated out of the cluster and all it’s data is spread across the remaining hosts.  VM’s will not be running in a degraded state during the maintenance window and will be able to tolerate the failures per their #FTT policy.

4th consideration

I mentioned there is a 4th consideration.  For the VM’s that you want protected with at least two copies of data (#FTT=1) even during maintenance windows, you have two options.  One is to set the #FTT=2 for those VM’s so they have 3 copies on 3 different hosts.  If one of those hosts is in maintenance mode and you didn’t choose “Full Data Migration” then you still have 2 copies on other hosts, thus the VM’s could tolerate another failure of a disk or host.  You could choose to create a storage policy based on vSAN with #FTT=2 and attach your most critical VM’s to it.  For more information on running business critical applications on vSAN see:

Running Microsoft Business Critical Application on Virtual SAN 6.0

I hope this helps in your decision making while administering vSAN.  I recommend testing the scenarios prior to implementing a cluster in production so you get a feel for the various options.

Podcast Fun!

In my role I have to drive a lot around New England. To pass the time I listen to a number of podcasts. Some of my favorites include:

Job Related:

Fun stuff:

But by far my favorite and the most entertaining is:

Virtually Speaking

I guess it’s partly because it focuses on storage for VMware environments, but, it’s also because Pete Flecha and John Nicholson are the right amount of funny, geek, and attitude all rolled into one.

A few weeks ago I had the chance to sit with John Nicholson and Duncan Epping to record some sound bits regarding customer experiences with vSAN in the field. I get to meet and work with a lot of remarkable customers up and down the eastern USA and over the last 3 years I’ve seen them accomplish great things with vSAN. You name an application or use case and it’s pretty likely its being done with vSAN. I was able to share a few stories as was Josh Fidel (@jcefidel) who’s doing great things with vSAN at customers in the Michigan, Ohio, Indiana, and Kentucky areas. He’s no SLOB and don’t let him fool you, he’s as smart as he is interesting. Check out what I mean by listening to this episode:

Virtually Speaking Podcast Episode 36: vSAN Use Cases

https://blogs.vmware.com/virtualblocks/2017/02/21/vspeaking-podcast-episode-36-vsan-use-cases/

 

 

 

vSAN and Data-At-Rest Encryption – Rebooted (i.e. Part 2)

 

Encryption is here, now shipping with vSphere 6.5.

I first wrote about vSAN and Encryption here:

Virtual SAN and Data-At-Rest Encryption – https://livevirtually.net/2015/10/21/virtual-san-and-data-at-rest-encryption/

At the time, I knew what was coming but couldn’t say. Also, the vSAN team had plans that changed. So, let’s set the record straight.

vSAN

  • Does not support Self Encrypting Drives (SEDs) with encryption enabled.
  • Does not support controller based encryption.
  • Supports 3rd party software based encryption solutions like HyTrust DataControl and Dell EMC Cloud Link.
  • Supports the VMware VM Encryption released with vSphere 6.5
  • Will support its own VMware vSAN Encryption in a future release.

At VMworld 2016 in Barcelona VMware announced vSphere 6.5 and with it, VM Encryption. In the past, VMware relied on 3rd party encryption solutions, but now, VMware has its own. For more details, check out:

What’s new in vSphere 6.5: Security – https://blogs.vmware.com/vsphere/2016/10/whats-new-in-vsphere-6-5-security.html

In this, Mike Foley briefly highlights a few advantages of VM Encryption. Stay tuned for more from him on this topic.

In addition to what Mike highlighted, VM encryption is implemented using VAIO Filters, can be enabled per VM object (vmdk), will encrypt VM data no matter what storage solution is implemented (e.g. object, file, block using vendors like VMware vSAN, Dell Technologies, NetApp, IBM, HDS, etc.), and satisfies data-in-flight and data-at-rest encryption. The solution does not require SED’s so it works with all the commodity HDD, SSD, PCIe, and NVMe devices and integrates with several third party Key Management solutions. Since VM Encryption is set via policy, that policy could extended across to public clouds like Cloud Foundation on IBM SoftLayer, VMware Cloud on AWS, VMware vCloud Air or to any vCloud Air Network partner. This is great because your VM’s could live in the cloud but you will own and control the encryption keys. And you can use different keys for different VM’s.

At VMworld 2016 in Las Vegas VMware announced the upcoming vSAN Beta. For more details see:

Virtual SAN Beta – Register Today! – https://blogs.vmware.com/virtualblocks/2016/09/07/virtual-san-beta-register-today/

This vSAN Beta includes vSAN encryption targeted for a future release of vSphere. vSAN Encryption will satisfy data-at-rest encryption. You might ask why vSAN Encryption would be necessary if vSphere has VM Encryption? I will say that you should always look to use VM Encryption first. The one downside to VM Encryption is that since the VM’s data is encrypted as soon as it leaves the VM and hits the ESXi kernel, each block is unique, so no matter what storage system that data goes to (e.g. VMware vSAN, Dell Technologies, NetApp, IBM, HDS, etc.) that block can’t be deduped or compressed. The benefit of vSAN encryption will be that the encryption will be done at the vSAN level. Data will be send to the vSAN cache and encrypted at that tier. When it is later destaged, it will be decrypted, deduped, compressed, and encrypted when its written to the capacity tier. This satisfies the data-at-rest encryption requirements but not data-in-flight. It does allow you to take advantage of the vSAN dedupe and compression data services and it’s one key for the entire vSAN datastore.

It should be noted that both solutions will require a 3rd party Key Management Server (KMS) and the same one can be used for both VM Encryption and vSAN Encryption. The KMS must support the Key Management Interoperability Protocol (KMIP) 1.1 standard. There are many that do and VMware has tested a lot of them. We’ll soon be publishing a list, but for now, check with your KMS vendor or your VMware SE for details.

VMware is all about customer choice. So, we offer a number of software based encryption options depending on your requirements.

It’s worth restating that VM Encryption should be the standard for software based encryption for VM’s. After reviewing vSAN Encryption, some may choose it instead to go with vSAN encryption if they want to take advantage of deduplication and compression. Duncan Epping provides a little more detail here:

The difference between VM Encryption in vSphere 6.5 and vSAN encryption – http://www.yellow-bricks.com/2016/11/07/the-difference-between-vm-encryption-in-vsphere-6-5-and-vsan-encryption/

 

In summary:

  1. Use VM Encryption for Hybrid vSAN clusters
  2. Use VM Encryption on All-Flash if storage efficiency (dedupe/compression) is not critical
  3. Wait for vSAN native software data at rest encryption if you must have dedupe/compression on All-Flash