To be, or not to be: that is the question:
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune,
Or to take arms against a sea of troubles,
And by opposing end them?
Today EMC has answered the question.
And the answer is, well, yes.
On the opening day of EMC World today, EMC announced several new backup offerings in what has been a steady stream of backup enhancements and announcements. Today’s most interesting to me is the new EMC Disk Library 4000.
The 4000 is an open systems virtual tape library (VTL) with some notable energy efficiencies built in. These include data de-duplication, disk spin down and high-capacity low-power 1TB disk drives. In combination, the potential power and cooling reductions can be as much as 47% compared to earlier alternatives.
What I find most reassuring is that energy efficiency shows at the end of the benefits list. It’s a part of the feature set. One of many important considerations but just one.
First, the idea of disk libraries is that it is disk made to look like tape. That’s the virtual part. That means traditional tape backup applications don’t see a difference, which makes for easy deployment. But there is a difference in performance. Disk is about five times faster.
Disk also allows for RAID protection and remote copies done oven the wire. No tape delivery trucks. Saves on gas. Avoids those embarrassing missing tape headlines.
Now I am sure that critics will point out that others have been shipping disk spin-down for some time now and that it’s no big deal that EMC has joined the pack.
Maybe.
But it sort of misses the point. EMC has shipped about 245 PB of VTLs so far. Add spin-down along with several other energy saving refinements, it makes a very good thing even better.
Energy savings come from three sources:
- Policy based data de-duplication gets rid of extra copies and reduces capacity requirements. Pretty straightforward.
- Low power 1 TB SATA II drives have a lower rotational speed – 5,400 rpm versus 7,200 for the older model. This reduces power by 32% but still minimizes performance impact. Pretty straightforward.
- Idle disks spinning down to save energy. This is the coolest part. Spin ‘em down when they aren’t being used. Spin ‘em up when you need them, say for backup/restore.
Spin-up happens automatically at the first I/O but there is a spin up delay. Still, this is a great match for virtual tape where operating systems and backup applications are already tolerant of the lag in tape devices.
The system also spins up disks at least once a day, just for exercise. The system also maintains spin up/down metrics and provides a report to show activities over the last 30 days.
So, the energy efficiency improves. Data integrity and product reliability aren’t compromised. The system reports out key metrics with no performance differences between spin-down and normal usage.
Pretty straightforward, eh Hamlet?
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