Tag Archives: VMware Cloud Foundation

vSAN 7.0U1 – A New Way to Add Capacity

October 2, 2020 MrVSAN Leave a comment

As we all know there are a number of ways of scaling capacity in a vSAN environment, you can add disks to existing hosts and scale the storage independently of compute, or you can add nodes to the cluster and scale both the storage and compute together, but what if you are in a situation where you do not have any free disk slots available, and / or you are unable to add more nodes to the existing cluster? Well vSAN 7.0U1 comes with a new feature called vSAN HCI Mesh, so what does this mean and how does it work?

Let’s take the scenario below, we have two vSAN clusters in the same vCenter, Cluster A is nearing capacity from a storage perspective, but the compute is relatively under utilised, there are no available disk slots to expand out the storage. Cluster B on the other hand has a lot of free storage capacity but is more utilised on the compute side of things:

Now the vSAN HCI Mesh will allow you to consume storage on a remote vSAN cluster providing it exists within the same vCenter inventory, there are no special hardware / software requirements (apart from 7.0U1) and the traffic will leverage the existing vSAN network traffic configuration.

This cool feature adds an elastic capability to vSAN Clusters, especially if you need to have some additional temporary capacity for application refactoring or service upgrade where you want to deploy the new services but keep the old one operational until the transition is made.

VMware has not left the monitoring capabilities of such use out either, in the UI you can monitor the usage of “Remote VM” from a capacity perspective as well as within the performance service

So this clearly allows dissagregation of storage and compute in a vSAN environment and offers that flexibility and elasticity of storage consumption are there any limitations?

A vSAN cluster can only mount up to 5 remote vSAN Datastores
The vSAN Cluster must be able to access the other vSAN cluster(s) via the vSAN Network
vSphere and vCenter must be running 7.0U1 or later
Enterprise and Enterprise Plus editions of vSAN
Enough hosts / configuration to support storage policy, for example if your remote cluster has only four hosts, you cannot use a policy which requires RAID6

So this is a pretty cool feature and sort of elliminates the need for Storage Only vSAN nodes which was discussed in the past at many VMworlds

Informational

Why vSAN is the storage of choice for VMware Cloud Foundation

December 4, 2019 MrVSAN Leave a comment

Recently VMware annouced that Cloud Foundation would support external storage connectivity, when I first heard this I thought to myself are VMware out of their minds? Amongst customers who I meet and talk to more or less on a daily basis, I also spoke to a lot of customers at VMworld about this but the stance or direction from VMware has not changed, if you want a truly Software Defined Data-Center then vSAN is the storage of choice.

So why have VMware decided to allow external storage in Cloud Foundation?

Many customers who are either about to start or have already started their journey to a Software Defined Data Center and/or Hybrid Cloud are still using existing assets that they wish to continue to sweat out, it may well be that their traditional storage is only a couple of years old and VMware are not expecting customers to simply throw out existing infrastructure that was either recently purchased or still being sweat out as that would be a tall ask right?

Customers also still have workloads that can’t simply be migrated to the full SDDC, they take some time to plan the migration, maybe there is a re-architecture of the workload that needs to be performed, or maybe there’s a specific need where a traditional storage array has to be used until any obstacles have been overcome, VMware recognises this hence the support for external storage in Cloud Foundation.

There are also specific use cases where Hyper Converged powered by vSAN isn’t an ideal fit, cold storage or archive storage is one of these, so supporting an array that can provide a suplemental storage architecture to meet these requirements is also a plus point.

Will I lose any functionality by leveraging traditional storage with Cloud Foundation? Simple answer is yes for the following reasons:

No lifecycle management for external storage through SDDC Manager which means patching and updating of the storage is still a manual task.
No single pane of glass management out of the box for external storage without installing third party plugins which in my experience have a tendancy to break other things.
No automation of stretched cluster deployment on external storage, all the replication etc has to be configured manually.
Day-2 operations such as Capacity Reporting, Health Check and Performance Monitoring are lost without installing any third party software for the external storage.
Auto deployment of the storage during a Workload Domain deployment, all the external storage has to be prepared beforehand.
Losing the true “Software Defined Storage” aspect and granular object control, currently external storage support for VVOLS is not there right now either.

Also remember that with Cloud Foundation, the Management Workload Domain has to run on vSAN, you can not use external storage for this.

So if you want a truly Software Defined Data Center with all the automation of deployment, all the nice built in features for day-2 operations then vSAN is the first choice of storage, if you have existing storage you wish to sweat out whilst you migrate to a full SDDC then that’s supported too, and yes you can have a vSAN cluster co-exist with external storage too, which makes migrations so much easier.

The other aspect to look at this is in a Hybrid Cloud or Multi Cloud strategy, Cloud Foundation is all about providing a consistent infrastructure between your private and public clouds, so if your public cloud is using Cloud Foundation with vSAN then the logical choice is to have vSAN as your storage for your Cloud Foundation Private Cloud to have that consistent infrastructure for your workloads no matter where they may run.

Informational

Oracle performance on HPE Synergy, vSAN and Intel Optane

March 11, 2019 MrVSAN Leave a comment

I had the privilege recently to work with a customer who had asked HPE to perform some performance benchmarks not just with HCI Bench, but because they run quite a lot of Oracle workloads they wanted to determine if the performance of vSAN on HPe Synergy would be sufficient in order to run their workloads.

Whilst agreeing on the hardware specification, the customer had referenced my previous post on Optane™ Performance and had asked HPE to perform the tests using Optane™ as the cache tier in the Synergy configuration, this was not only to provide a superior performance experience, but it also would free up two capacity slots in the disk tray of the chassis per Synergy compute node meaning the customer could have more capacity.

Synergy Specification:

HPE Virtual Connect SE 40Gb F8 Module for Synergy
HPE Synergy D3940 Storage Module with SAS expanders
3x HPE Synergy 480 Gen10 nodes, each equipped with:
2x Intel® Xeon® Gold 6154 CPU @ 3.00GHz
2x Intel® Optane™ 750 GB SSD DC P4800X Series PCIe (x4)
768 GB Memory (24x 32 GB RDIMM @ 2666 MHz)
2x Disk Group config with 1x Optane + 3x 800GB SAS per Disk Group
LACP based 40GbE interconnection between Compute Nodes

Please note: At the time of writing the 750GB U.2 Optane drives were undergoing certification for HPE Synergy.

In order to perform the Oracle workload testing HPE engaged with their own internal Oracle specialists to determine the correct workloads that needed to be performed, and with a target of <2ms specified by the customer they decided to use Kevin Closson’s SLOB tool, SLOB was configured in the following way:

128 SLOB Schemas
Each Schema was 8GB in Size
Total of 1TB Test data

For the purpose of testing HPE decided that they would perform different tests in the following way:

(A) Single Oracle VM Instance with 128 Schemas, 70% Read, 30% Write
(B) Single Oracle VM Instance with 128 Schemas, 50% Read, 50% Write
(C&D) Single Oracle VM Instance with Heavy REDO activity and Large SGA and REDO_STRESS=Heavy, 50% Read, 50% Write, with 128 Schemas and 32 Schemas
(E) Single Oracle VM Instance
(F & G) 2 Parallel Oracle VM Instances with 64 / 128 Schemas Each, 70% Read, 30% Write

Test	SGA	PGA	Schemas	Scale	REDO_STRESS
A	5G	1G	128	8G	Lite
B	5G	1G	128	8G	Lite
C	256G	100G	128	8G	Heavy
D	256G	100G	32	8G	Heavy
E	5G	1G	128	8G	Lite
F	5G	1G	64	8G	Lite
G	5G	1G	128	8G	Lite

Before the tests were performed, and Oracle I/O Calibration was performed which is a feature of Oracle Databases and is used to assess the performance of the I/O subsystem by issuing an I/O intensive read-only workload in order to determine the maximum IOPS and throughput whilst maintaining close to 0ms latency.

Each test ran for 60 minutes in order to ensure enough data was filling up the write buffer, so let’s take a look at the results:

As you can see from the results, the target of <2ms was achieved successfully and at one point with two oracle VMs achieveing a staggering 250k IOPS at 1.305ms latency is very impressive across a 3-Node cluster, not only was the customer pleased with the results, but the Oracle Specialist within HPE said that the results exceeded their expectations also.

So as you can see, a composable infrastructure deployment of vSAN such as HPE Synergy with Intel Optane™ can still deliver the same levels of performance as standard rack mount servers, combined with VMware Cloud Foundation delivering a full SDDC package from both a hardware and software perspective.

It's all about VMware vSAN