If your VM is running on a NFS datastore and Changed Block Tracking (CBT) is enabled, you might experience the following symptoms:
When removing the snapshot of the virtual machine residing on the NFS storage in an ESX/ESXi 4.1 host, you may experience these symptoms:
The virtual machine appears to be in a hung state within the console view
The virtual machine stops responding to ping requests
The virtual machine is inaccessible via remote desktop
But why is this VM freezing? The explanation is the locking mechanism which NFS uses:
This issue may occur if you are using a backup application that utilizes Changed Block Tracking (CBT) and the ctkEnabled option for the virtual machine is set to true. The virtual machine becomes unresponsive for up to 30 seconds as NFS locks on the .ctk file are changed.
The workaround is to disable CBT:
Wait for the virtual machine to become responsive and for the snapshot operation to complete.
Schedule an outage window for the affected virtual machine.
Shut down the virtual machine.
In the Inventory pane, right-click the virtual machine and click Edit Settings.
Click the Options tab and click General.
Click Configuration Parameters.
If the ctkEnabled parameter is not listed, click Add Row, add ctkEnabled, and set it to false.
Power on the virtual machine.
This workaround can impact the backup performance because you can’t use CBT. To Disable CBT in a Veeam job, you have to edit the job and disable CBT in the Advanced Settings under the vSphere tab:
Or if you’re using PHD Virtual Backup you can change the CBT settings in the Options tab on the properties page of a Backup Job:
Earlier this year I wrote a post about how to query the Veeam Backup SQL database to get the total job running time. I wanted to see if I was able to run this Query via Powershell. So I started to search on Google and I found a great series of articles on http://www.databasejournal.com about how to use Powershell to access Microsoft SQL databases. After reading part two, I was able to create a script to run my Query.
The only thing you have to change are the next three variables:
Run the next script to query the Veeam Backup database and return the total job time.
$dbServer="servername\instance"$db="VeeamBackup"$veeamJob="VeeamJobName"$Query="SELECT [job_name],CONVERT(char(10),[creation_time], 101) AS start_date `
,CONVERT(varchar, [creation_time], 108) AS job_start,CONVERT(char(10), [end_time], 101) AS end_date `
,CONVERT(varchar, [end_time], 108) AS job_end, `
LEFT(CONVERT(VARCHAR,CAST([end_time] AS DATETIME)-CAST([creation_time] AS DATETIME), 108),5) AS total_time `
FROM [VeeamBackup].[dbo].[BSessions] WHERE [job_name] = '$veeamJob' ORDER BY start_date"$SqlConnection=New-ObjectSystem.Data.SqlClient.SqlConnection$SqlConnection.ConnectionString ="Server=$dbServer;Database=$db;Integrated Security=True"$SqlCmd=New-ObjectSystem.Data.SqlClient.SqlCommand$SqlCmd.CommandText =$Query$SqlCmd.Connection =$SqlConnection$SqlAdapter=New-ObjectSystem.Data.SqlClient.SqlDataAdapter$SqlAdapter.SelectCommand =$SqlCmd$DataSet=New-ObjectSystem.Data.DataSet$SqlAdapter.Fill($DataSet)
$DataSet.Tables | Format-Table-AutoSize
New Features • Added support for replication and remote backup over slow and unreliable links with moderate packet loss. Resolved Issues • .NET Framework bug affecting some non-English locales (confirmed to exist on Norwegian locale) results in sporadic corruption of backup files chain (missing VBK files, extra VRB files). • Backup file repair after unsuccessful backup cycle fails if backup storage is low on free disk space. • Network backup in service console agent mode may fail with the following error: “Failed to validate command "dd if="/vmfs/volumes/…”. • Attempting to enable SSH connection to ESX host on Japanese locale fails with the following error: ["Could not find any resources appropriate for the specified culture or the neutral culture. Make sure "VeeamSSH.strings.ja.resources" was correctly embedded or linked into assembly "Veeam.SSH" at compile time, or that all the satellite assemblies required are loadable and fully signed."]. • Veeam VSS processing fails on specific OS configurations with various “Access denied” errors while specified VSS account has suffient permissions. • Veeam VSS processing fails on specific OS configurations with the following error: "The specified service does not exist as an installed service". • Veeam VSS integration does not support guests with Datacenter Edition of Microsoft Windows 2003.
More and more organizations are choosing VMware Infrastructure to virtualize their mission‐critical applications (Active Directory, Exchange, SharePoint, SQL Server) to create a flexible, easily administered virtual infrastructure. Virtual machines (VMs) and any applications they contain must be protected against failure. Typically, in the virtual world, this is done by performing an image‐level backup of the whole machine (for instance, using VMware Consolidated Backup). This method results in what is known as a crash‐consistent image. Restoring a crash‐consistent image is essentially equivalent to rebooting a server after a hard reset. For operating systems, this has not been an issue, since they can easily handle this type of activity. For database applications as well as for applications featuring replication, however, such a restore will often result in lost data, data corruption, or application failure. To illustrate this concept, let’s review the consequences of using different VM disaster recovery methods for one of the most common mission‐critical applications: a Microsoft Active Directory domain controller (DC). Depending on the solution used, the following results will be achieved: