Pure Storage – Page 13 – Cody Hosterman

July 30, 2018

Virtual Volumes and Array Snapshots Part I: Managed Snapshots

One of the first technical benefits users can enjoy around VVols is the use of snapshotting. Snapshots created through VMware of VMs have always been a point of contention which as severely limited their usability (see a post I did around the performance impact of them here).

With VVols, when you right-click on a VM and choose take snapshot, VMware does not create the performance-impacting delta VMDK files that were traditionally used, but instead VMware entirely offloads this process to the array. So the array creates the snapshots and VMware just tracks them.

But since VMs are now a collection of individual volumes on the array (a VVol is just an array volume) you can also snapshot and restore individual virtual disks as well directly on the array.

So what does all of this mean?

Continue reading “Virtual Volumes and Array Snapshots Part I: Managed Snapshots”

July 19, 2018

Site Recovery Manager and ActiveCluster Part III: Creating Protection Groups and Recovery Plans

Now that all of the prerequisites are complete, it is time to start creating protection groups and recovery plans.

This is part 3 of this series, the earlier parts were:

Continue reading “Site Recovery Manager and ActiveCluster Part III: Creating Protection Groups and Recovery Plans”

July 19, 2018

Site Recovery Manager and ActiveCluster Part II: Configuring SRM

In my last post, I walked through configuring ActiveCluster and your VMware environment to prepare for use in Site Recovery Manager.

Site Recovery Manager and ActiveCluster Part I: Pre-SRM Configuration

In this post, I will walk through configuring Site Recovery Manager itself. There are a few pre-requisites at this point:

Everything that was done in part 1.
Site Recovery Manager installed and paired
Inventory mappings in SRM are complete (network, folders, clusters, resource pools etc).
Downloaded and installed the FlashArray SRA 3.x or later on both SRM servers.

Continue reading “Site Recovery Manager and ActiveCluster Part II: Configuring SRM”

July 19, 2018July 20, 2018

Site Recovery Manager and ActiveCluster Part I: Pre-SRM Configuration

About four years ago, we (Pure Storage) released support for our asynchronous replication and Site Recovery Manager by releasing our storage replication adapter. In late 2017, we released our support for active-active synchronous replication called ActiveCluster.

Until SRM 6.1, SRM only supported active-passive replication, so a test failover or a failover would take a copy of the source VMFS (or RDM) on the target array and present it, rescan the ESXi environment, resignature the datastore(s) then register and power-on the VMs in accordance to the SRM recovery plan.

The downside to this of course is that the failover is disruptive–even if there was not actually a disaster that was the impetus for the failover. But this is the nature of active-passive replication.

In SRM 6.1, SRM introduced support for active-active replication. And because this type of replication is fundamentally different–SRM also changed how it behaved to take advantage of what active-active replication offers. Continue reading “Site Recovery Manager and ActiveCluster Part I: Pre-SRM Configuration”

July 9, 2018March 4, 2020

Troubleshooting Virtual Volume Setup

VVols have been gaining quite a bit of traction of late, which has been great to see. I truly believe it solves a lot of problems that were traditionally faced in VMware environments and infrastructures in general. With that being said, as things get adopted at scale, a few people inevitably run into some problems setting it up.

The main issues have revolved around the fact that VVols are presented and configured in a different way then VMFS, so when someone runs into an issue, they often do not know exactly where to start.

The issues usually come down to one of the following places:

Initial Configuration
Registering VASA
Mounting a VVol datastore
Creating a VM on the VVol datastore

July 5, 2018October 31, 2019

PowerCLI and vVols Part II: Finding vVol UUIDs

One of the great benefits of vVols is that fact that virtual disks are just volumes on your array. So this means if you want to do some data management with your virtual disks, you just need to work directly on the volume that corresponds to it.

The question is what virtual disk corresponds to what volume on what array?

Well some of that question is very array dependent (are you using Pure Storage or something else). But the first steps are always the same. Let’s start there for the good of the order.

June 7, 2018

What’s New in Purity 5.1: WRITE SAME Handling Improvement

In Purity 5.1 there were a variety of new features introduced on the FlashArray like CloudSnap to NFS or volume throughput limits, but there were also a variety of internal enhancements. I’d like to start this series with one of them.

VAAI (VMware API for Array Integration) includes a variety of offloads that allow the underlying array to do certain storage-related tasks better (either faster, more efficiently, etc.) than ESXi can do them. One of these offloads is called Block Zero, which leverages the SCSI command called WRITE SAME. WRITE SAME is basically a SCSI operation that tells the storage to write a certain pattern, in this case zeros. So instead of ESXi issuing possibly terabytes of zeros, ESXi just issues a few hundred or thousand small WRITE SAME I/Os and the array takes care of the zeroing. This greatly speeds up the process and also significantly reduces the impact on the SAN.

WRITE SAME is used in quite a few places, but the most commonly encountered scenarios are:

Creating an eagerzeroedthick virtual disk
Zeroing-on demand in zeroedthick disks or thin disks Continue reading “What’s New in Purity 5.1: WRITE SAME Handling Improvement”

May 31, 2018July 11, 2018

What’s New in Core Storage in vSphere 6.7 Part V: Rate Control for Automatic VMFS UNMAP

vSphere 6.7 core storage “what’s new” series:

VMware has continued to improve and refine automatic UNMAP in vSphere 6.7. In vSphere 6.5, VMFS-6 introduced automatic space reclamation, so that you no longer had to run UNMAP manually to reclaim space after virtual disks or VMs had been deleted.

Continue reading “What’s New in Core Storage in vSphere 6.7 Part V: Rate Control for Automatic VMFS UNMAP”

May 16, 2018March 21, 2019

ESXi iSCSI, Multiple Subnets, and Port Binding

With the introduction of our Active-Active Synchronous Replication (called ActiveCluster) I have been getting more and more questions around multiple-subnet iSCSI access. Some customers have their two arrays in different datacenters, and also different subnets (no stretched layer 2).

With ActiveCluster, a volume exists on both arrays, so essentially the iSCSI targets on the 2nd array just look like additional paths to that volume–as far as the host knows it is not a two arrays, it just has more paths.

Consequently, this discussion is the same as if you happen to have a single array using more than one subnet for its iSCSI targets or if you are using active-active across two arrays.

Though there are some different considerations which I will talk about later.

First off, should you use more than one subnet? Well keeping things simple is good, and for a single FlashArray I would probably do that. Chris Wahl wrote a great post on this awhile back that explains the ins and out of this well:

http://wahlnetwork.com/2015/03/09/when-to-use-multiple-subnet-iscsi-network-design/

Continue reading “ESXi iSCSI, Multiple Subnets, and Port Binding”