Your data is exploding! You need more disk space now! You have a disk system that is over-priced because your disk vendor knows it’s more trouble to migrate your data than to pay the extra cost… you should be mad that someone prices their product based on how trapped you are with your data on their disk system. Sound familiar? Do they have you convinced you have to pay that much money for a reliable disk system? This is a marketing strategy and is designed to maximize their profits, not ease your pain.
I have your answer, arm yourself with disk virtualization system that can service enable most other disk systems on the market today and provide a wide range of data services that are needed in today’s exploding data environments. Actually this model makes the pain go away all together and makes data migrations a snap. The best part for the bean counters is it gives you all the leverage you need to cut costs on future disk purchases without sacrificing the reliability of your disk systems or the integrity of your data. So IT is happy and accounting is happy. How is this possible? Service enable existing production luns using a disk independent storage virtualization platform. Here is how it works:
Say there are luns from a current disk system presented directly to servers. Data needs to be migrated but you cannot afford down time during production and you cannot have a prolonged outage to migrate data. (To another tier of disk that’s faster or to another vendor’s disk) Here is where the storage virtualization platform comes in. To implement, the entire process would take about 15 minutes of downtime per server. Just shut one server down at a time. Present the target luns from the server you shut down to a new storage gateway that will now control the disk. In the new storage gateway a resource will be created (small in size) to house the new virtual headers for each lun that will be created in this process. The storage gateway will become the server’s new disk target. In the new storage gateway the disk will be discovered and seen as a raw disk device. A process can then be performed that will import the existing disk, the existing header on the disk will be read and retained while the new header is written to new disk resource that was created and assigned for housing the virtual headers. Once this process is performed the existing disk is ready to be presented back to the server through the new storage gateway. A fibre channel or ISCSI client can then be created in the storage gateway and the server assigned as that client. As long as the luns are assigned with the same lun numbers the server will boot up and see no change whatsoever in the disk or the data on that disk. That lun now becomes a service enabled device and all services offered by the storage gateway can be performed against that device.
Some of the capabilities of the storage gateway should be as follows:
- Mirroring to new storage (can be most any 3rd party disk you wish to purchase)
- Snapshots
- DR replication
- Create production ready devices from existing snapshots
And there’s many more…
The most interesting option is the mirroring. In some storage gateways you can choose to mirror a service enabled device to another disk system and since it is all controlled by the storage gateway you can mirror while the server is up and running production, swap the mirror without taking anything down and then break and delete the mirror that’s on the disk being replaced. Data was just migrated to a new disk subsystem without downtime (except for a single server reboot to service enable the disk) and no interruption in production.
Here are some advantages of this model:
- Install two highly available storage gateway s that failover – High availability (HA)
- Install a second lower tier disk subsystem to mirror data to and be used as production in case of a primary disk subsystem failure – the failover would be automatic and mirrors would swap back and synchronize automatically when the main disk subsystem comes back on-line. (That should be the functionality requirement for automated failover)
- Disk becomes a commodity and you can save a lot of money that way…..far more than the cost of the storage gateway system. Great return on investment and a way to cut ongoing costs.
- The storage gateway can also be used as a shared storage platform for virtualization further validating the initial investment and providing a substantial ROI.
- Different tiers of disk can be presented to the storage gateway and data mirrored between the tiers without downtime or interruption of service.
To discuss, tell me I am completely insane, or otherwise give me a rough time feel free to call or email me:
Jeff Sabella, Sr. Storage Engineer
(440) 498-2300
Email: support@chicorporation.com
