Originally posted by: TonyPearson
An avid reader of this blog pointed me to a blog post [
A Small Tec DIGG on IBM XIV], byGowri Ananthan, a System Engineer in Singapore.Basically, she covers past
battles, er.. discussions between me and fellow blogger BarryB from EMC, and [
blegs] foranswers to three questions.
Gowri, here are your answers:
- Q1. Does IBM offer a Pay-as-you-Go [PAYGO] upgrade path for its IBM XIV disk storage system?
The concern was expressed as:
PAYGO also requires the customer to purchase the remaining capacity within 12 months of installation. So it is More of a 12-month installment plan than pay-as-you-grow.
A1. Actually, IBM offers several methods for your convenience:
- With IBM's Capacity on Demand (CoD) plan, you get the full framewith 15 modules installed on your data center floor, but only pay for the first four modules 21 TB, then pay for 5.3TB module increments as you need them over the next 12 months. This is ideal for companies that don't know how fast they will grow, but do not want to wait for new modules to be delivered and installed when needed.
- With IBM's Partial Rack offering, you can get a system with as little as six modules (27TB),and then over time, add more modules as you need. This does not have to be done within 12 months, you can stay at six modules for as long as you like, and you can take as long asyou want to add more modules. When you are ready for more capacity, the drawer or drawerscan be delivered, and installed non-disruptively.
Neither of these are "payment installment plans", but certainly if you want to spread yourcosts into regularly-scheduled monthlypayments across multiple years, IBM Global Financing can probably work something out.
- Q2. Does IBM consider the XIV as green storage?
The concern was expressed as:
You are powering (8.4KW) and cooling all 180 drives for the whole duration, whether you're using the capacity or not. is it what you called Greener power usage..?
A2. Yes. IBM considers the IBM XIV as green storage. The 8.4KW per frame is lessthan the 10-plus KW that a comparable 2-frame EMC DMX-950 system would consume. Theenergy savings in IBM XIV comes from delivering FC-like speeds using slower SATA disks that rotate slower, and therefore take less energy to spin.In the fully-populated or Capacity on Demand configuration, you would spin all 180disks. However, using the partial rack configuration, the 6-module has only 40 percent ofthe disks, and therefore consumes only 40 percent of the energy. If you don't plan to storeat least 20-30 TB, you might consider the DS3000, DS4000, DS5000, or DS8000 disk system instead.
- Q3. How do you connect more than 24 host ports to an IBM XIV?
The concern was expressed as:
And finally do not forget my question on 24-FC Ports… Up to 24 Fiber Channel ports offering 4 Gbps, 2Gbps or 1 Gbps multi-mode and single-mode support.Stop.. stop.. how you gonna squeeze existing bunch of FC cables in 24 ports?
A3. Best practices suggest that if you have ten or more physical servers, each with two separate FC ports, then you should use a SAN switch or director in between. If you require four ports per server, then you would need a SAN switch beyond six servers to connect to the IBM XIV. If you consider that 24 FC ports, at 4Gbps, represents nearly 10 GB/sec of bandwidth, you will recognize that this is not a performance bottleneck for the system.
Gowri, I hope this answers your questions!
technorati tags: IBM, XIV, Gowri Ananthan, EMC, BarryB, CoD, partial rack, full rack, FC, SATA, DMX-950, green, disk system, multi-mode, single-mode, best practices