Consumers and clients are the lifeblood of any business and good customer service is essential to the growth of a business. Having a Customer Service Support group is an inexpensive way of maintaining customer loyalty and overall customer satisfaction. Gartner estimates it costs four to 10 times as much to capture a new customer as it does to provide good service to an existing customer. Call center representatives serve your clients, customers and prospective customers, on a daily basis. They are trained to handle situations and make the caller feel satisfied after reaching them. However, the majority of call center reps make the vital mistake of not being honest if they are not knowledgeable about a specific subject. It is important to train call center representatives on being honest and handling special situations both verbally and specifically. In these cases it may be beneficial to have a tiered group of customer care specialists depending on your business to escalate issues and triage calls. If your employee is a very good communicator and enjoys serving people, then you can concentrate less on them, and more on other areas of your business.

I’ve come across a number of customer sites that have only a single backup stream from each client running sequentially to a tape drive device.  While there is a concern that the time to recover increases if you have multiplexed data on a tape, there is also a need to properly stream the tape drive.  For the most part these nice little pieces of hardware do not have a slow speed and will be required to stop and restart as data is presented.  This is known as “shoe shining” and can take a large toll on the device resulting in frequent repairs and even slower backups.

The following examples expand each step in multiplexing backups to illustrate how all tape drive devices should be used.

1. Each example shows 5 Clients, each client having 4 possible jobs streams
2. Each stream runs at 5 MB/Sec
3. Tape device can handle 80MB/Sec

Figure A
The example in Figure A shows the consecutive approach currently deployed causing a cascading slow down affect.  There is simply not enough data being presented to the tape drive for it to stream effectively.

Figure B
The example in Figure B is an improvement as each client can send a backup to the tape drive, shortening the overall backup window, and utilizing the tape drive at 20MB/Sec.

Figure C
The examples in Figure C and D show the possible configuration should the specific client not be able to handle multiple data streams or if everything could be sent to the tape drive at the same time.  The bottom right needs 100MB/Sec, but with only a slight compression ratio this scenario would keep

Figure D
the tape drive streaming at an optimized rate.  If the original example had each stream taking one hour, the backup window would need to be 20 hours to complete; where as the final example could finish all backups in only 1 hour.

Is CLARiiON a 5×9s Box?

Often I find myself engaged in projects where I am asked to document current storage tiers and develop future state tiers of storage. In characterizing each tier, performance and availability are among the key metrics that define each tier. There is the perception with some IT professionals that CLARiiON is a 5×9s storage platform. It seems that the justification of availability classification depends on who you talk to.

If you look through EMC’s literature, they seem to reference perceived availability based on their customer’s uptime, not as a design spec. This leaves us a subjective sampling of configurations that EMC would undoubtedly pick only the most redundant and stable.

So I can take a couple of Iomega USB drives, and with the right software and configuration, I could also meet 5×9s over a 1yr time period. This doesn’t mean that one of those USB drives meets a 5×9s design spec. Ok, maybe I’m overreaching a bit, but you get my point.

Symmetrix traditionally has been a closed architecture that requires EMC SEs and SAs to configure, update, make bin file and firmware updates. In the past there were a lot more changes on a Symm that required downtime than today. That being said, they’ve always touted the Symm as being 5×9s. Is the criterion for 5×9s a sliding metric? So I’m not even sure scheduled downtime should be considered in 5×9s.

The CLARiiON on the other hand is more open to customer configuration, reconfiguration etc… This makes it subject to hardware downtime. I know, this is a sweeping statement but I have Murphy’s Law behind me. The fact that a Symm requires EMC engineers to schedule and make critical changes kind of reminds me of the seatbelt in my Subaru. It is !!SO!! annoying that you have no choice but to put it on to stop the “fasten your seatbelt” alarm. Seatbelts are the one thing that protects passengers most in an accident, and most affects the car’s safety rating.

So there are 3 ways I hear people referring to uptime or availability

• Perceived availability - Metric driven by field performance
• Downtime for maintenance - I disagree with this one. This sound more to me like serviceability rather than availability
• Unplanned downtime - Influenced (reduced) by redundancy in architecture. I think this is the real metric that should define availability - 4×9s vs. 5×9s

So, I’m inclined to say that the CX-3 with active passive controllers would not be 5×9s but the CX-4 would. I would only consider chassis redundancy in the CX or DMX availability metric, so just up to the controller. This would not include redundant FA or host paths. As long as there are two controllers with two active/active paths to the SAN, I’d consider it 5×9s. After that it’s up to the SAN to provide redundancy to the host. I would also not include RAID configuration in this metric.

By James Brissenden, GlassHouse Senior Consultant, Storage and Data Protection

Wireless Mobility Security by Robbie Higgins