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As written in a previous post, with the introduction of vSphere 5.0 in addition to the installable version of vCenter Server (which still requires a Windows operating system), there is also a Virtual Appliance version (called VMware vCenter Server Virtual Appliance).
VMware vCenter Server Virtual Appliance (vCSA) is a VMware’s official VA that can be used as an alternative way to implement a full vCenter Server, instead to install on a Windows Server (that must be deployed first). Unlike the installable version, it does not require a Windows Server license and instance, but is rather based on a Linux distribution (it’s a SuSE Enterprise).
Across the various versions after the 5.0, this appliance has been improved to make it more effective and optmized, both in the deploy (available finally also in the form of single OVA file), both in the occupation of space (now the downloadable OVA is smaller also the ISO). Also the embedded database has been improved from the in-flexible IBM DB2 has changed to a more function PostgreSQL (or vPostgres as named by VMware). And finally the upgrade process has been improved and simplified.
With the release of vSphere 5.5, vCenter Server Appliance has become even more attractive not just for test environments or small installations, but also for medium and large size, because it introduces new limits (using the embedded database) really interesting: maximum 100 hosts or 3000 VMs (this must not surprising that much, since it was already known that these limits were reached in the infrastructure for the Hands on Labs).
So vCenter Server Appliance could be the solution and the first option in each deployment? Before all you have to make some evaluation on the possible drawbacks:
- it’s a virtual appliance , as this can be an advantage or a disadvantage depending on your point of view (for further considerations refer to this post)
- could only be deployed as a virtual machine, this is not necessary a disadvantage, but must be consider (for more consideration see also this post)
- it requires more memory rather than the installable version (minimum 8 GB RAM), however if you install the embedded database and put the vSphere Web Client Server on the installable versione, it easy require the same amount of memory
- it supports only its embedded database or an external Oracle database, Microsoft SQL Server is currently not supported (maybe in future versions)
- it lacks of the linked mode support, that limits its use in large environments with multiple vCenter Server (actually could not then be a limit if these large environments are managed by vCloud Director or VMware Horizon View, where the management interface will be another one than and vCenter Server is just an infrastructure block)
- there isn’t a Linux version of vSphere Update Manager (VUM), so you need a Windows server for implement it (and then you lose the advantage of saving a Windows license and certainly no longer have the approach to single appliance that implements all services in a box)
- there isn’t a Linux version of VMware Horizon View Composer, so you need a Windows server for implement it (and then you lose the advantage of saving a Windows license and certainly no longer have the approach to single appliance that implements all services in a box)
- vCenter Server Linked Mode does not work (it is based on Active Directory Lightweight Directory Services instances)
- vCenter Server Heartbeat is not compatible with vCSA and therefore the only solution for the vCenter Server high availability remain VMware HA (which may be fine for most cases, but does not meet some more strictly SLAs)
- there may be problems with some plugins, especially in the case of plug-ins for the old vSphere Client
Of course there are several pros:
- deployment is really faster (in 10 minutes you have a system ready to be configured)
- the download is simplified (and even more compact ISO vCenter installed)
- update is relatively simpler than the installable version and can update/upgrade not just the vCenter Server but also the the entire machine (and the related OS)
- in version 5.5, its embedded database can cover many of the needs of SMB and medium-sized enterprise
- already includes an embedded database and all the components of vCenter Server (apart VUM), including the Dump and Syslog Collector
- the Web Client server part is already included and ready for use (more time saved in the deployment, although from version 5.5 this part became also a default component installed by Simple Mode)
- is a virtual appliance, with the advantages of a black box approach, but there could be also some disadvantage depending on your point of view (for further considerations refer to this post)
For more information see also those posts:
- VMware vCenter Server 5.5: Installable vs Appliance
- What has changed in vCenter Server Appliance 5.5 (vCSA)?
- Windows vCenter Server versus vCenter Server Appliance
- KB 2002531 (Services bundled with vCenter Server Appliance)
- VMware vCenter Server Virtual Appliance (vCSA) Feature Parity
- vCenter Server Appliance 5.5 limitations