Infrastructure at your Service

Category Archives: Hardware & Storage

David Barbarin

Weird issue with sys.fn_hadr_backup_is_preferred_replica() function

By | Hardware & Storage | No Comments

A couple of days ago, I faced a weird backup issue with SQL Server AlwaysOn and availability groups at one of my customer (thank to him to point out this issue ). After installing our DMK tool (Database Management Kit) about database maintenance for AlwaysOn, my customer noticed that their databases have not backed up. Ouch … what’s going on? I never ran into this issue before… Do the problem comes from our tool? In…

 
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David Barbarin

Vsphere 6.0 improvements for Windows Failover Clusters

By | Hardware & Storage | No Comments

A couple of days ago, VMWare announced vSphere 6.0. I guess many of our customers have been waiting for this new release and probably I will see in the next few months this new version rolled out on the top of their virtual SQL Server vitual machines. If you missed this event, you can still register here. I’m not a VMWare expert but VSphere 6.0 seems to be a storage-oriented version with a lot of improvements…

 
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Grégory Steulet

All you need to know about Oracle Database licensing with VMware

By | Hardware & Storage | 79 Comments

You are running Oracle on VMware and are not 100% sure that you are compliant with the Oracle licensing rules? This article is for you! As I have been confronted several times with Oracle License reviews with VMware installations, I decided to write this article in order to provide answers to the most frequent questions I have received from customers. Introduction Licensing is not an easy topic to address and this difficulty is not specific…

 
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David Barbarin

WSFC : Manual or automatic failover? That is the question!

By | Hardware & Storage | 2 Comments

During the night, you receive an alert concerning your SQL Server failover cluster or your availability groups and you’re in panic mode because the message displayed is : a failover has occured .. see the log for more details … So keep quiet and after connecting to your environment you are not able to find anything … What was happen? Maybe someone has triggered manually a failover and you are not aware of it. I’m…

 
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David Barbarin

SQL Server: Forced failover with AlwaysOn & Availability Groups

By | Hardware & Storage | No Comments

During a workshop at one of my customer about the implementation of SQL Server AlwaysOn and availability groups, I had an interesting discussion. It was about asynchronous replication between 2 replicas and the effect of the forced failover operation with allowed data loss. Does SQL Server resynchronize availability databases if I loose some transactions during the failover process? The quick answer is yes but probably the most interesting question is how SQL Server achieves resynchronization…

 
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Alain Lacour

High availability in the Oracle landscape

By | Hardware & Storage | No Comments

It’s now several weeks I attended some event about high availability (HA). But what is actually high availability? According to our friend Wikipedia, HA is based on 3 main principals: Elimination of Single Point of Failure (SPoF) Reliable crossover (with minimal or no downtime) Detection of failures when they arrive If those principals are met, end users may never realize about a failure. The aim of that blog is not to dive into too much…

 
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David Barbarin

SQL Saturday 323: SQL Server AlwaysOn and availability groups session slides

By | Hardware & Storage | 4 Comments

This SQL Saturday’s edition in Paris is now over. It was a great event with a lot of French and international speakers. There were also many attendees indicating that this event is a great place to share about SQL Server technologies. Maybe the Montparnasse tower in Paris played a role here with its panoramic view over Paris from the 40th floor! For those who didn’t attend on Saturday, you will find our SQL Server AlwaysOn…

 
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Nathan Courtine

Backup a SQL Server database from On-Premise to Azure

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SQL Server database backup & restore from On-Premise to Azure is a feature introduced with SQL Server 2012 SP1 CU2. In the past, it could be used with these three tools: Transact-SQL (T-SQL) PowerShell SQL Server Management Objects (SMO) With SQL Server 2014, backup & restore can also be enabled via SQL Server Management Studio (SSMS). Concept This feature is quite similar to a “classic” backup & restore tool. Indeed, the main different lies in…

 
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David Barbarin

SQL Server 2014: Availability groups failover impossible with Failover Cluster Manager

By | Hardware & Storage | 2 Comments

A couple of weeks ago, I worked for a customer that wanted to implement SQL Server 2012 (and not SQL Server 214) AlwaysOn with availability groups. During our tests we performed a bunch of failover tests and the customer tried to perform a failover of one of the installed availability group by using the failover cluster manager (FCM). Of course, I told him this is not best practice because the failover cluster manager is not…

 
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Franck Pachot

Oracle et Dbvisit Replicate pour migrer sans arrêt de service… et sans stress

By | Hardware & Storage, Oracle | No Comments

Je viens d’assister au Webinar Zero Downtime Migration pour Oracle, présenté par Chris Lawless qui est récemment passé de Product Manager Golden Gate à Product Manager Dbvisit.  Je vais détailler ici un point très important évoqué par Chris Lawless. La migration par réplication n’est pas seulement envisagée pour éviter un arrêt de service. Arrêt nécéssaire lors de la migration proprement dite (qui peut aller de quelques minutes à plusieurs heures en fonction de la taille…

 
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