Simpler storage management for VOEs

Via Web Services, Xiotech moves storage administration out of its device-centric ghetto into the world of virtual operating environments.

By Jack Fegreus, openBench Labs

The rule of thumb for staffing storage administrators today pegs 25TB as the nominal amount of storage that a single administrator can handle. More importantly, a full-featured 25TB SAN array costs less than $50,000. That means operating expense (OpEx) outlay will be greater than capital expense (CapEx) outlay in the first year. It also explains why senior IT executives rank IT Service Management (ITSM) as strategic as the virtualization of an operating environment.

Traditionally, IT has tried to improve productivity by acquiring software tools designed to resolve ad hoc resource problems. That "better firefighting" approach was doomed to failure from inception. Studies consistently cite changes in the computing environment introduced by IT as the cause of 80% of all computing disruptions. Given that statistic, ITSM relies on a classic quality control solution to process management—a scheme favored by CEOs—to automate standard IT administrator tasks.

Software typically used by IT, however, greatly complicates any application of process management or an attempt to establish a virtual operating environment (VOE). IT tools are all but universally device-centric, while virtualization is about generic devices and process management is about work flows across devices. For IT, the mandate is to move operations out of the device-centric ghetto.

Xiotech's Emprise 7000 SAN storage system fits perfectly into the VOE and ITSM construct through a management framework that employs standard Web Services protocols to automate storage-related tasks not just across multiple storage systems, but also across operating systems and VOEs. Utilizing protocols such as XML, SOAP, and WSDL, Emprise 7000 management software, dubbed ICON Manager, leverages Web Services support built into Windows Server, Linux, and VMware ESX Server.

The impact of ICON Manager on system and storage management through the use of Web Services shatters previous notions of single-pane-of-glass management. Within IT, the notion of single-pane management has become associated with software that allows a single class of devices, such as disk arrays, to be virtualized and managed as a single logical device. ICON Manager goes beyond the notion of just managing a class of devices to managing all of the devices involved in a storage function.

The extent to which this approach slashes OpEx costs associated with system and storage management can best be seen in the provisioning of storage devices for virtual machines (VMs). The use of VMs in a VOE, such as VMware, greatly benefits IT's bottom line with respect to improved resource utilization. Nonetheless, there is also an added inherent complexity for IT administrators, who must learn to deal with the layers of indirection in a VOE.

Using any storage array without the ICON Manager framework, IT administrators must invoke three distinct (and disjointed) views of the storage environment to complete the task of provisioning storage for a VM: the view of the storage array's GUI; the view of either the ESX Server or vCenter Server (formally VirtualCenter) via the VMware Infrastructure Client; and the view of the VM's native OS management GUI. In sharp contrast, ICON Manager is able to provide a single global view for the storage provisioning process via the interoperability derived through Web Services. That integrated function-centric approach significantly reduces the steps, time, and expertise required to provision a VM.

Xiotech takes that integration one step further by providing a Web Services SDK. Applications drive the utilization of storage, and that makes applications and the servers on which those applications run essential members of any end-to-end storage-provisioning process. With the Xiotech SDK, software development teams at user sites have the tools needed to integrate software applications with the Emprise 7000 storage system to automate repetitive or complex tasks. With the Web Services SDK, business applications can be extended to become self-provisioning, which reduces the total cost of ownership (TCO) of an Emprise 7000 system even more significantly.

Xiotech's ICON Manager offers IT administrators a simple process-oriented solution to begin optimizing storage as a service. The critical differentiator for the software is the use of Web Services to communicate with storage systems and servers. With Web Services providing a transparent integration mechanism to link the Emprise 7000 with standard Windows and Linux operating systems, along with VMware ESX Servers and vCenter Server, ICON Manager presents administrators with an extensive set of views that cluster around the different roles and information needs of system and storage managers.

For administrators, the ICON Manager views are a powerful alternative to invoking separate management applications for each device class involved in a storage management process. By eliminating the need to work with both array and server consoles when performing complex or repetitive process tasks, such as provisioning logical volumes or virtualizing volume ownership, ICON Manager reduces the probability that an IT administrator will introduce errors. As a result, IT is able to more rigorously assert control over storage management processes and thereby significantly reduce TCO for storage resources.

What's more, the Web Services scheme is agent-less. While there is tight integration across all devices involved in storage processes, storage systems and servers remain entirely independent. There are no dependencies for IT administrators to track or worry about when performing upgrades or doing maintenance on any of these resources.

Server View
ICON Manager's Server View is designed to help administrators provision and manage storage for applications on Windows or Linux servers. That makes the appearance of Server View—in particular its logical hierarchy of managed objects—unlike other management GUIs for storage resources.

To enable an administrator to create and modify storage volumes with a minimal number of steps from a single console, the Server View layout displays all servers that have a SAN fabric path to the Emprise 7000 storage system and all of the logical volumes assigned to those servers. Moreover, to support ongoing management processes, such as expanding volume capacity, creating point-in-time snapshots using copy-on-write technology, and making full block-level copies, Server View provides detailed logical volume attributes that include total capacity, used space, and free space. Thanks to Web Services, Server View provides all of the volume details normally associated with a local server disk management GUI.

Using the Server View within the ICON Manager interface, we were able to manage storage directly on Windows and Linux host servers without having to invoke server-based management tools.

To speed administration and reduce the possibility for errors when provisioning storage for servers, Server View provides a number of wizards that are typical of what can often be found within a server OS. Using Server View, the storage provisioning process begins with the choice of a server. That choice will dictate the launch of an OS-specific wizard. The Create Volume wizard guides the process from the creation of a logical volume on the Emprise 7000 system to the formatting and mounting of the logical volume on the target host server. What's more, the Server View wizard strictly enforces the use of a configuration template whenever a new logical volume is created.

Using the Create Volume wizard in Server View, we provisioned logical volumes on Windows and Linux servers. We created oblaTest for a Windows server, which automatically mounted the drive as volume E: and formatted it as an NTFS volume. We then created oblLinTest for a CentOS server, which automatically mounted the volume and formatted it as an ext3 volume. In both cases, we only interacted with the Emprise 7000.

Storage View
For storage administrators, who need to ensure that storage resources such as the Emprise 7000, are optimally utilized, ICON Manager provides several role-based views, including Storage View, Physical View, and Statistics View.

Storage View offers IT administrators a more traditional storage management layout, based on logical volumes. Within Storage View, administrators can organize the screen layout by characteristics such as virtual volumes, volume mirrors, and server host initiators. In this way, Storage View provides storage administrators, who are accustomed to the GUIs of standard Fibre Channel arrays, an intuitive environment for dealing with such advanced functionality as volume expansion, block copy, volume mirroring, and point-in-time snapshots.

Storage administrators can also drill down on logical volume properties to determine the layout details of a volume with respect to the ISE modules in the Emprise 7000 system. This is paticularly important whenever it is necessary for IT to initiate configuration changes.

Having provisioned our servers via Server View, we switched to Storage View to detail storage resource usage and perform other storage-centric tasks that would be required of a storage administrator. Through Storage View we examined capacity utilization of oblbTest, which was the source for a local mirror, dubbed oblb2Test, and a one-time block copy, oblbTest_Copy.

Having provisioned our servers, we switched to the storage-centric tasks of detailing storage resource usage via the Storage and Statistics Views. Through these views we were able to detail resource utilization in depth, including storage on logical mirrors and RAID striping of ISEs. What's more, we were able to monitor and confirm the I/O throughput of a high-performance logical volume in a transaction processing test scenario.

We set up our oblLoad benchmark to generate random 8KB reads in a database access pattern on our oblPerfDisk virtual volume. At the same time, we launched the ICON Manager Statistics View, which provides real-time statistics on both throughput and capacity usage. Both the benchmark and Statistics View confirmed that we were processing roughly 32,000 I/O requests per second with an average access time that was under 5ms.

Virtual View for VMware
The real fireworks begin when Virtual View is invoked under ICON Manager for a VMware ESX Server VOE. With ESX Server and vCenter Server both supporting Web Services as the interoperability method of choice, provisioning storage for VMs, which can take dozens of steps—including multiple storage rescans—is just as simple as configuring storage for a physical server.

With Virtual View, administrators have a unified view of their VMware Virtual Infrastructure, with which they can explore and map all VMware systems and storage relationships. There are analogs to all of the capabilities that ICON Manager provides to physical servers. Within Virtual View, resources can be displayed in either a VM-centric or a Datastore-centric manner. What's more, there are automated wizards to create, expand, or delete volumes for VMs—both as VMDKs and RDMs—as well as create, expand, or delete VMFS-formatted Datastores.

The most dramatic improvements in storage management productivity came with the provisioning and management of storage resources for a VMware VOE. As with physical servers, we were able to look at resources either in a VM-centric manner or in a Datastore-centric framework. From the VM-centric view, we were able to select a specific VM and launch a wizard to provision that VM with either a VMDK or an RDM logical volume.

Like their Server View wizard counterparts for provisioning storage on physical servers, the Virtual View wizards create end-to-end processes to provision volumes for ESX Servers and VMs. What makes the Virtual View wizards so valuable for IT is the fact that as a manual process, storage provisioning is far more complex than storage provisioning for a physical server.

In a VOE, storage provisioning for a VM first involves creating a logical volume for the ESX Server. That logical volume must either be encapsulated as a VMDK volume in a Datastore or mapped as an RDM volume with pointers in a Datastore. Then the ESX Server must pass the VMDK or RDM volume to the VM, which must mount, create and format its own logical disk. This process requires many more steps than a simple physical server and involves multiple storage device scans.

By looking at our VMware VOE resources from a Datastore perspective, we were able to launch a wizard-driven end-to-end process to create oblDS, a VMFS-formatted Datastore for the ESX Server.

We created and expanded logical volumes for VMs as well as logical volumes as Datastores for an ESX Server. In all cases, after setting a set of standard properties, the storage process ran correctly to completion in a fraction of the time needed when using a standard storage server.

Via ICON Manager's wizard, the inherent complexity of provisioning VMs is simplified, while the templates that drive the process ensure perfect accuracy every time the process is invoked. By leveraging standard Web Services protocols, ICON Manager radically departs from the notion of just managing a class of devices to managing all of the devices involved in an end-to-end storage process. In so doing, ICON Manager shatters previous notions of single-pane-of-glass management.



UNDER EXAMINATION: Storage server management software


Xiotech Emprise 7000 Storage System
Xiotech ICON Manager


(3) Dell PowerEdge servers
-- Windows Server 2003  
-- Cent OS 
-- Hyper-V
-- VMware ESX Server 3.5


-- ICON Manager integrates storage-related server tasks on servers running Windows or Linux with typical storage device tasks via Web Services to provide end-to-end process management.

-- Wizards launch seamless end-to-end storage processes that create, expand or delete virtual volumes for VMs, as well as VMFS-formatted Datastores for ESX Servers.

-- ICON Manager automates complex, manual, repetitive tasks, which reduces the possibility for errors introduced by IT administrators to reduce storage-resource TCO.

This article was originally published on March 25, 2009