Snapshot 101: Copy-on-write vs Redirect-on-write

Good post by W. Curtis Preston (thank you)

There are two very different ways to create snapshots: copy-on-write and redirect-on-write. If IT is considering using the snapshot functionality of their storage system, it is essential to understand which type of snapshot it creates and the pros and cons of using either method.

Rather than the more common term volume, this column will use the term protected entity to refer to the entity being protected by a given snapshot. While it is true that the protected entity is typically a RAID volume, it is also true that some object storage systems do not use RAID. Their snapshots may be designed to protect other entities, including containers, a NAS share, etc. In this case, the protected entity may reside on a number of disk drives, but it does not reside on a volume in the RAID or LUN sense.

Read on here

Traffic Isolation Zoning – The mistake of FOS

30506851-road-traffic-isolation-facilities-in-the-street-closeup-of-photo

Good post by Erwin van Londen (thank you)

If there is one thing I would consider “the” blunder of FOS engineering it has to be Traffic Isolation zoning. I mean, creating such an administrative nightmare with obscure directions causing confusion and nasty pitfalls when one thing goes wrong is in many occasions a recipe for disaster.

Read on here

How often do you upgrade your storage array software?

Good post by Alex Galbraith (thank you)

Upgrades are scary!

Having managed and implemented upgrades on highly available systems such as the old Sun StorageTech line of rebranded HDS USP/VSP arrays back in the day, I can tell you that we did not take upgrades lightly!

Unless there was a very compelling reason for an upgrade, the line taken was always “if it ain’t broke, don’t fix it”, but then we were looking after storage in a massively high security environment where even minor changes were taken very seriously indeed.

Read on here

Where VSAN doesn’t shine: Sources explain EMC’s ScaleIO purpose

Good post by Chris Mellor (thank you)

EMC introduced its scale-out ScaleIO Node virtual SAN a couple of weeks ago, with hybrid flash-disk and all-flash server chassises. It overlaps as a product with EMC-owned VMware’s VSAN, and therefore EMC’s EVO:RAIL implementation of that, and also competes with scale-out all-flash arrays.

Discussions with sources have clarified EMC’s thinking on the topic, and showed that the overlap is less than originally thought.

Read on here

VVOLs and VMware

Post by Christine Taylor (thank you)

The definition of VVOLs is simple but the effect is ground-breaking. Here is the simple definition part: Virtual Volumes (VVOL) is an out-of-band communication protocol between array-based storage services and vSphere 6.

And here is the ground-breaking part: VVOLs enables a VM to communicate its data management requirements directly to the storage array. The idea is to automate and optimize storage resources at the VM level instead of placing data services at the LUN (block storage) or the file share (NAS) level.

Read on here

Conventional Storage QoS falls short on VMware and Virtualized Workloads

Post by George Crump (thank you)

An increasing number of storage systems are coming to market with Quality of Service (QoS) functionality that allows an administrator to guarantee and in some cases, limit the amount of storage performance that a VMware or other virtualized workloads will experience. This is an important feature as the number and variety of workloads continues to increase in the data center. QoS should allow mission critical workloads to be intermixed with less critical workloads, without fear of the impact of a noisy neighbor stealing all available storage performance.

Read on here

SDS – The Missing Link – Storage Automation for Application Service Catalogs

Post by Rawlinson Rivera (thank you)

Automation technologies are a fundamental dependency to all aspects of the Software-Defined Data center. The use of automation technologies not only increases the overall productivity of the software-defined data center, but it can also accelerate the adoption of today’s modern operating models.

In recent years, a subset of the core pillars of the software-defined data center has experienced a great deal of improvements with the help of automation. The same can’t be said about storage. The lack management flexibility and capable automation frameworks have kept the storage infrastructures from delivering operational value and efficiencies similar to the ones available with the compute and network pillars.

VMware’s software-defined storage technologies and its storage policy-based management framework (SPBM) deliver the missing piece of the puzzle for storage infrastructure in the software-defined data center.

Read on here

Why Virtual Volumes?

Post by Andrew Sullivan (thank you)

How many times in the last 3-4 years have you heard “Virtual Volumes”, “VVols”, “Storage Policy Based Management”, or any of the other terms associated with VMware’s newest software-defined storage technology?  I first heard about VVols in 2011, when I was still a customer, and the concept of no longer managing my virtual machine datastores, but rather simply consuming storage as needed with features applied as requested, was fascinating and exciting to me.

Read on here

The More You Know Series: Forced Flushing

Good post by Reliant Technologies (thank you)

Over the past few weeks, we have talked a lot about different key performance indicators and how these may indicate an underlying issue associated with your performance problems. One of the recurring issues brought up was forced flushing. So, today we are going to dive a little deeper into what forced flushing is.

Read on here

Why Have VVOLs Taken So Long to Deliver?

Post by Chris M Evans (thank you)

Another VMworld has come and gone and still we haven’t seen the production deployment of VVOLs.  Just to recap, VVOLs are the evolution of the packaging of virtual machines that currently reside in data stores.  The main benefit is to be able to apply storage performance and availability policies to a VM object rather than an entire datastore as we do today. Although we’ve seen demonstrations of VVOLs for some time, VVOL code has not yet made it into a GA vSphere launch.  Presumably this will change with the release of vSphere 6.0 sometime next year.

Read on here