Storage management places a burden on more than just traditional storage administrators. Today many VMware (or VI) administrators find that they are spending more and more time on storage operations and storage-related issues.
For example, the task of bringing storage online is a multistep process that requires the coordination of information and tasks between storage and VMware admin teams. Unfortunately for VI admins, they are responsible for a large portion of the tasks related to this fundamental operation.
Figure 1) VMware storage provisioning processes. Note that most tasks are done by VMware admins.
NetApp engineering has worked with VMware engineering to simplify storage management. The result is our plug-ins for VMware® vCenter™ Server: the Rapid Cloning Utility (RCU) and the Virtual Storage Console (VSC). When used together they streamline storage operations for both storage admins and VI admins.
If you’ve been reading Tech OnTap in recent months, you may be familiar with these utilities. (Refer to A Quantum Leap in Virtual Management for more.) In this article, I talk about the overall operational impact of these plug-ins, rather than delve into the specifics of each tool. In doing so I introduce a new model for VMware storage management—one that significantly simplifies storage provisioning, cloning, monitoring, and management.
The New Model for Storage Admins
In the new model, storage admins continue to be responsible for configuring physical storage systems, providing data protection, and managing overall utilization, as always. Once the physical architecture is deployed, however, all that a NetApp storage admin supporting VMware has to do is provision pools of storage resources (aggregates, FlexVol® volumes, and storage network interfaces) that VI admins can then configure as needed for use with VMware virtual machines.
This model significantly simplifies storage admin tasks while allowing the VMware admin to directly provision and manage datastores and the storage constructs associated with them (LUN masking, storage I/O path management, etc.) using the resources assigned by the storage admin.
To assign resources, the storage admin logs in to vCenter and opens the RCU configuration panel. This is where he or she may assign a controller or controllers and storage resources. Once a resource has been assigned it is used exclusively by virtual infrastructure. Resources not assigned are ignored and are inaccessible to the virtual infrastructure.
Figure 2) Assigning storage resources to VMware using RCU.
To prevent further changes the storage administrator has the option to lock or restrict the ability to assign additional resources. (Taking this step is a recommended best practice.) Checking a box followed by entering a user name and password is all that’s needed to perform the securing process.
That's it! That’s all a storage admin needs to do to provide storage for a VMware environment. There are no LUNs, no LUN masking, no NFS exports, no multipathing.
The New Model for VMware Admins
Now, let’s look at the impact the new model has on VMware admins in terms of provisioning and managing datastores.
Provisioning Datastores from Assigned Resource Pools
Figure 3) Provisioning datastores from vCenter.
Instant Provisioning of VMs
Today, this technology has evolved to the point where you can deploy a single VM, multiple VMs, or a pool of virtual desktops almost instantly, without consuming any additional storage in the process. A VMware admin can deploy space-efficient clones by simply selecting a running or shut-down VM, template, or vApp as a starting point.
Unlike some cloning technologies, NetApp clones are permanent, high-performance VMs that can be treated in the same manner as any other VM. There are no restrictions. Perhaps as a result, NetApp FlexClone technology has been integrated into vCenter, View Manager, XenDesktop, and Quest vWorkspace.
Audit and Automate VMware Storage Settings
This audit process can be run at any time without disruption to production, providing the ability to enable optimal uptime as your environment grows. These storage settings are currently not covered by VMware host profiles, so the NetApp plug-ins extend the completeness of an automated deployment process. The ability to update host settings is limited to vSphere™ hosts. VI3 hosts lack the API calls to automate this process. Should a system be identified as being out of compliance, the storage settings can be changed manually as outlined in TR-3428.
Report on Storage Details and Utilization
A key benefit is the ability to report on storage utilization through the various storage layers beginning at the datastore and ending at the NetApp aggregate (a collection of RAID-protected disks). The value of NetApp integration with vCenter becomes obvious when storage-saving technologies such as data deduplication, FlexClone, or thin provisioning have been enabled.
Report Storage Faults
Enable Optimal I/O Settings Within VMs
Second, MBRscan and MBRalign combine to audit and correct the partitions and file systems within a VM to make sure that VM I/O operations are aligned to storage system block boundaries. The problem of virtual machine disk alignment is not unique to VMware, nor is it unique to NetApp storage. This problem can occur in any virtual environment on any storage platform. (I wrote a recent post on this issue for my Virtual Storage Guy blog with help from Duncan Epping of VMware.)
This problem occurs because, by default, many guest operating systems, including Windows® 2000 and 2003 and various Linux® distributions, start the first primary partition at sector (logical block) 63. This behavior leads to misaligned file systems because the partition does not begin at a block boundary. As a result, every time the virtual machine wants to read a range of data blocks, an additional block has to be read. This results in unnecessary load on the storage controller. You can learn more about the problem and how to correct it in TR-3747. This document has been reviewed and approved by VMware, Microsoft, Citrix, and NetApp.
Table 1) Storage system and VMware plug-in requirements.
The advantages created by the use of NetApp storage and our vCenter plug-ins are substantial. The original multistep provisioning model presented in the introduction (see Figure 1) is effectively reduced to a simple two-step model.
Figure 4) New VMware provisioning model made possible by RCU and VSC.
Working from within vCenter, both storage admins and VMware admins can complete tasks faster with fewer complications and much more control.
Got opinions about VMware storage provisioning?
Ask questions, exchange ideas, and share your thoughts online in NetApp Communities.
This NetApp Community is public and open website that is indexed by search engines such as Google. Participation in the NetApp Community is voluntary. All content posted on the NetApp Community is publicly viewable and available. This includes the rich text editor which is not encrypted for https.