EqualLogic VMware iSCSI Setup – Part 2: Network Configuration

SAN LAN Network

The EqualLogic iSCSI network consists of the switches, EqualLogic arrays and ESX hosts, all of which need configuring properly to make the most of each others load balancing, performance and availability features. In terms of the network fabric, there are a few things we need to consider:

  1. High availability – multiple links and switches to provide redundancy
  2. Performance – elimination of bottlenecks
  3. Management – monitoring and management network

This guide can apply to a range of hardware as long as we are using EqualLogic arrays and VMware ESX/ESXi hosts. The switches can be Dell or Cisco for example, as long as they are on the Dell Approved Hardware list. The hardware I used when making this guide is as follows:

  • 2 x PowerConnect 7048
  • 6 x PowerEdge R710
  • 2 x EqualLogic PS6000

Here is some brief detail about my hardware specifications, and how I put the key design considerations mentioned earlier into practice when configuring each component. Continue reading

Veeam Backup job failed. Cannot create a shadow copy of the volumes containing writer’s data.

Backup job failed

Backup job failed

Occasionally one of our Veeam backup jobs will fail and most of the time it is due to shadow copy or VSS writer issue which a simple reboot will resolve, this solution has become our default answer to a failed backup with an error mentioning the words “shadow copy” or “VSS”. One of our SQL servers had a failed backup last night and gave us the error “Cannot create a shadow copy of the volumes containing writer’s data”, here is the full error message:

Failed to prepare guest for hot backup. Error: VSSControl: -2147467259 Backup job failed. Cannot create a shadow copy of the volumes containing writer’s data. VSS asynchronous operation is not completed. Operation: [Shadow copies commit]. Code: [0x8004231f].
Error: VSSControl: -2147467259 Backup job failed. Cannot create a shadow copy of the volumes containing writer’s data. VSS asynchronous operation is not completed. Operation: [Shadow copies commit]. Code: [0x8004231f].

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EqualLogic VMware iSCSI Setup – Part 1: Preparation

Dell VMwareEqualLogic VMware iSCSI setup best practices have gone through many changes recently, fortunately Dell and VMware seem to have partnered well and made some good improvements towards the integration of their products. Development may well settle down now along with the release of ESXi 5.0/5.1 and Dell’s own Multipathing Extension Module (MEM) available to those with Enterprise vSphere licencing.

There is a lot of documentation – whitepapers, manuals and blog posts on the topic of iSCSI setup which can become overwhelming quite quickly.The setup is actually really simple with the correct up to date documentation to hand. The entire process of the SAN network installation can be broken down into the following steps:

  1. SAN fabric design
  2. Switch configuration
  3. Array configuration
  4. Host configuration
  5. Monitoring

Continue reading