Jan 152011
 

Okay, so you tell me you need an EqualLogic iSCSI SAN SAS array. But do you really need a SAS array…? I mean, do you reeeeeeeally need a SAS array…? Let’s look at the facts and see if what you have and what you need match up…fair…?

There’s no doubt that you’ve heard that SAS is fast, right? Oh, yeah. In fact, EqualLogic SAS units are extremely fast and have been known (and documented) to even outperform their fibre channel counterparts. Take that, fibre channel!!!

The SAS EqualLogic iSCSI SAN units can come in 10K or 15K RPM drive speeds within the EqualLogic PS4000X, PS4000XV, PS6000X, PS6000XV, PS6010X and PS6010XV models. For the EqualLogic PS6500X and PS6510X models, only 10K RPM drive speeds are available…for now.

So, let’s take a look at what you have. Hmmm…you have some file data and maybe some Exchange and SQL. Yes, database applications are usually pretty demanding and may merit faster drive speeds…SAS would definitely do the trick…

However…

Have you done a perfmon yet…? What’s a perfmon you might ask…? It stands for Performance Monitor (perfmon), and it’s a tool that helps you assess the (storage) traffic on your network. It’ll show you how many IOPS (Input/Output Operations Per Second) your network is pushing through, where your peak traffic times are and all that good stuff. Federal Appliance happens to coordinate these for free for our clients in an attempt to more accurately assess which EqualLogic iSCSI SAN you might need…whether it’s a SAS or a SATA.

Rule of thumb?

If your IOPS are more than 600 or so, you might want to consider a SAS unit. If it’s under this, you might be better off staying with a SATA unit. Why pay for more horsepower than your network really needs…? SAS does cost more…about 20% to 40%, on average, but if you don’t need it don’t buy it. I have plenty of clients running multiple database applications in their environment across an EqualLogic SATA unit…and it’s more than enough for them. Every client is different.

But there are other circumstances that might drive the need for an EqualLogic SAS unit over a SATA one…such as file size, imaging requirements, disaster recovery, replication needs, additional database applications, SAP implementations, ERP implementations, Oracle, DB2, clustering, future growth, and so on.

Still not sure with EqualLogic SAN is right for you…? Neither am I…heck, that’s why we need to talk. Now. Until we discuss your requirements and assess your traffic with a perfmon or some other network tool, we really won’t know for sure. But knowing what you need will help you build a business case for that EqualLogic SAN you’ve always wanted. You know, that nice new EqualLogic PS6000XV-9.6TB array that those financial tightwads in upper management declined last year…? Well, now you’ve got ammo…so go ahead, buy that PS6000XV-9.6TB…we’ve got your back…

Jan 062011
 

One of the first questions I get from clients who look into the Dell EqualLogic PS6000 series is “Why is it so expensive…?” (get a self-service EqualLogic price quote here if you want to compare yourself).

This question is normally posed shortly after they strive to recover from a five-minute bout of sticker shock as I aid them in readjusting their jaw (which has fallen to the floor by this time…). But this question is a valid one…I mean, you can get the same capacity in the EqualLogic PS4000 for about 30% less cha-ching…so what’s the difference…?

First, I tell my clients to look at their company’s needs and answer a few questions:

  • How much growth are you experiencing year-by-year?
  • How much data do you acquire year-by-year?
  • What (database) applications are you running?
  • Are you looking to do Disaster Recovery or deploy an iSCSI SAN in multiple locations?
  • How many Gigabit Ethernet ports do you really need from your EqualLogic SAN?
  • What are you looking to accomplish long-term with your iSCSI SAN?

Here’s the bottomline…and maybe even a rule of thumb: 1) If your organization is not going to be growing and / or adding tons of data over the next 3 to 5 years, 2) don’t need anymore than two (2) Gigabit Ethernet ports for management into your EqualLogic iSCSI SAN, 3) don’t foresee pooling anymore than two physical EqualLogic arrays into one logical SAN for each location, then I’d say go for an EqualLogic PS4000E (or PS4000X or PS4000XV, depending on your applications and IOPS).

The EqualLogic PS4000 series is going to have about 30% to 40% less horsepower than the EqualLogic PS6000 series will produce, so if you can settle for that and tuck away the pride (cough, cough…), the EqualLogic PS4000 series will not only be more cost effective but will probably meet your requirements as well. Plus, it still has all the bells and whistles the big boy (PS6000 series) has.

If you have the slightest doubt about any of the above criteria, then don’t compromise your organization’s storage needs and consider the EqualLogic PS6000. Which do we recommend…? The PS6000 series, of course…it’s more money…I mean, it’s more flexible and more powerful and you don’t have to worry about any limitations. But, hey, it’s your budget and storage area network…figure out your needs and go from there…

Tony Gonzales
Sales & Technical Manager
4Storage
www.4Storage.com