Heterogeneous virtualization is giving early adopters much to smile about, from advanced services to improved utilization.
“Heterogeneous virtualization” is a mouthful, but Chuck Long has no problem singing the technology’s praises. A storage administrator for Safelite Autoglass, Long discovered he could recapture unused disk capacity and better utilize his storage by virtualizing his mixed IBM storage environment with the vendor’s SAN Volume Controller.
In turn, that has meant recouping the cost of extra storage and saving time on management and maintenance.
“I can create a [partition] on the Shark and carve it up and assign it to servers as I want. If later the need for that disk disappears, I can add it back into the common pool,” Long says, adding that he’s used IBM’s virtualization scheme on a Cisco MDS director-level switch at the Columbus, Ohio, company since last summer.
IBM was the first of the large systems vendors to introduce virtualization of heterogeneous arrays with its SAN Volume Controller software, which resides on Intel Xeon servers or on Cisco’s MDS 9000 Series Fibre Channel switches. Now, heterogeneous virtualization is the au courant promise of all major storage systems vendors, with all agreeing that this is a necessary starting point for easier management, improved utilization, and data services such as replication and information life-cycle management (ILM).
Long says he has virtualized about two-thirds of the data on his storage-area network (SAN) and hopes to virtualize all 27T bytes of data residing on IBM storage systems. “Virtualization has allowed us to resolve the issue of those ‘pesky’ little 1 to 5 Gig spaces that are left over on a volume and are just too small to use. We are able to bring all those smaller logical volumes into the SAN Volume Controller and combine them to make a larger usable space. This lets us use 100% of our storage with no wasted space,” Long says.
“We can also use the migration tool to move logical volumes from one storage device to another or just move it to another area on the same device without the end users ever losing connection,” he adds. “This allows us to do maintenance on storage devices without causing downtime for the host.”
Moving data from one array to another is a breeze, Long says. “With the SAN Volume Controller, all the drivers are there. We migrated 2T bytes in an hour and a half. Nobody had any idea it was being done,” he says.
Old storage, new life
At United Loyalty Services, heterogeneous virtualization has given old EMC Symmetrix storage a new purpose, says Gary Pilafas, senior storage architect for the Chicago company. Pilafas is virtualizing the data between disparate storage arrays using Hitachi Data Systems’ new TagmaStore high-end array, which can attach to other Hitachi storage and to IBM, EMC, HP and Sun arrays.
“I virtualized the midrange Hitachi 9585 with Fibre Channel and Serial [Advanced Technology Attachment] drives, and an EMC Symmetrix 4 and 5 behind the Hitachi TagmaStore,” Pilafas says. He did so “just to see if I could do it, for migration purposes – to be able to move data from one array to another – and so I can use my old arrays as a tier of inexpensive” just a bunch of disks, he says.
With Hitachi’s HiCommand Storage Services Manager software, storage architects can view and manage all the boxes attached to the TagmaStore as a single pool of data. “Because I’ve virtualized my storage environment, I can manage it from one interface rather than several I had to use before,” he says.
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While his team is saving time (and money) on storage management, virtualization also could lead to savings on maintenance contracts, Pilafas says. “I could actually drop my maintenance agreements on older EMC Symmetrix 8730 storage and go on a time-and-materials basis and only keep maintenance on the expensive storage I own. As drives spare out, I can get them replaced on a time-and-materials basis,” he says.
The tail end
Sun and EMC will bring up the tail of the virtualization bandwagon next year.
When Sun ships its Enterprise Storage Manager, Unity 3.0 release software next spring, its midrange StorEdge 6920 Storage Array will be able to virtualize data from HP Enterprise Virtual Arrays and EMC Clariion CX700 arrays. Once data is virtualized between these arrays, Sun plans to let the StorEdge 6920 host local mirroring, migration, redundancy and remote replication applications for disaster recovery and ILM.
EMC plans to debut its Storage Router software/hardware in the first half of 2005. The Storage Router consists of two Intel Xeon servers and an intelligent Fibre Channel switch that handles the I/O requirements of the application. Unique metadata information resides on the servers, where instructions to perform virtualization, replication or mirroring operations reside.
