All Paths Down (APD) is a situation which occurs when a storage device is removed from the ESXi host in an uncontrolled manner, either due to administrative error or device failure. Over the previous number of vSphere releases, VMware has made significant improvements to handling the APD, the All Paths Down, condition. This is a difficult condition to manage since we don’t know if the device is gone forever or if it might come back, i.e. is it a permanent device loss or is it a transient condition.
In this post, I want to highlight a number of storage improvements made in vSphere 5.1 that are going to be leveraged by the next release of vCloud Director.
This is possibly the most exciting new storage feature in the vSphere 5.1 release. Space Efficient Sparse Virtual Disks (or SE Sparse Disks for short) were designed to alleviate two issues. Let’s describe these issues first of all. Problem Statement #1 – Let’s take a Guest OS running on a linked clone (View desktop if you will), and this Guest OS issues a 4KB write. vmfsSparse disk (which is the format used by traditional linked clones) has a block allocation unit size of 512 bytes. In other words, this Guest OS is backed by 512 byte blocks. Depending on the…
Welcome to the first in a series of posts related to new storage enhancements in vSphere 5.1. The first of these posts will concentrate on VMFS. There are two major enhancements to VMFS-5 in the vSphere 5.1 release. VMFS File Sharing Limits Increase Prior to vSphere 5.1, the maximum number of ESXi hosts which could share a read-only file on a VMFS filesystem was 8. This was a limiting factor for those products and features which used linked clones. Linked Clones are simply “read/write” snapshots of a “master or parent” desktop image. In particular, it was a limitation for vCloud…
I’d met Virsto Software at previous VMworld conferences, but never had a chance to have a meaningful discussion regarding their products and solutions. On a recent trip to the US, I had the pleasure of meeting with Eric Burgener at the Virsto offices in Sunnyvale. He kindly took the time to give me an overview of their Virsto for vSphere 1.5 product.
I recently had the pleasure of chatting with Jesse St. Laurent, Product Director at a new storage startup called SimpliVity. SimpliVity finally exited stealth mode today, but has been around since the end of 2009, with development starting in earnest in 2010. The name of the hardware storage appliance which SimpliVity have just announced is the OmniCube. Having asked Jesse to describe the features of the appliance, he listed the following:
EMC Isilon are providing even further vSphere integration features in their upcoming ‘Mavericks’ release of their OneFS operating system. This is great to see. The integration is in the area of vSphere APIs, both for Array Integration (VAAI) & Storage Awareness (VASA). Let’s have a look at the VAAI enhancements first.