Here we go round the firmware tree, the firmware tree, the firmware tree …

May 30, 2012

We seem to be back on the drive firmware update path again. I recently had an issue with a customer system running desktop drives (yes, I know they shouldn’t but they do).  I checked the drive firmware with what I knew to be the latest from my drive vendor mate … and it was out of date.

So very quickly told the customer to check for latest/later version with vendor. Lo and behold they came up with an even newer version than I was aware of.

So the moral of the story is … contact your drive vendor and ask them what the latest version is for that drive. Don’t tell them what you have, just ask what the latest version is.

I don’t see why my friends in the drive business should escape all this firmware fun! :-)

Ciao
Neil

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Why didn’t you call? …

May 9, 2012

Can’t remember exactly what that line is from (possibly a TV ad from my younger days), but it basically tells a story in the RAID industry. I’m continually getting customers (a) telling me what they are doing, then (b) ending up asking me how to put it all together because “they are not really experts at this” etc. Considering the fact that normally these people are doing something pretty bizarre or high-end, this is somewhat strange.

So …

Basic tips for looking at how to build a system. These are very, very generic, but there are some truisms to these, with one basic proviso – IF YOU ARE NOT 100% SURE OF WHAT YOU ARE DOING – CALL YOUR RAID VENDOR (in this case Adaptec of course).

Capacity – performance – redundancy (paranoia) – cost

These are the basic building blocks of storage – and you can’t have them all. Of course if you disregard cost you can get whatever you want in this world, but there are not many customers who actually mean it when they say “we are not worried about the cost, we just want the best” etc (they pretty quickly change their tune), so I’ll base everything below with a strong eye towards the “cost” of the system).

Capacity – it’s pretty easy to get big storage these days – 3tb drives are commonplace, but keep an eye on performance while you are calculating this variable. A general rule of thumb would be that the more spindles you have working for you, the quicker the box will be. Eg – 4 drives in a RAID 10 will be quicker than 2 drives in a mirror. So keeping cost down too much can often hurt your performance, though it generally doesn’t hurt your redundancy.

So think carefully about capacity, but don’t let it be the only consideration.

Performance – what exactly are you doing with your data, and what sort of data is it? Notice that we haven’t even bothered looking at hardware yet – the data type will determine most of the configuration. This can be broken down into basically streaming and random data – streaming can be in either direction (capturing or delivering content) and random is generally read (with a lesser degree of write – eg database).

So if you are doing streaming data then you will go for a parity raid (5, 6, 50, 60) as the parity calculations won’t hurt your performance and you’ll get a lot more capacity for your dollar. If on the other hand you are doing random data like a database, then you’ll be more interested in a non-parity raid such as 1 or 10.

Streaming data works fine on SATA drives (7200rpm), but random data (database) tends to work much better on SAS (10K or 15k drives). Of course SSD comes into play here but the cost generally wipes them out for anything except small specialised installations.

So if you are doing streaming data you are probably looking at SATA drives in a RAID 5, 6 or 50, while if you are doing database you are probably looking at SAS drives in a RAID 10, 1E or 1 (in that order please).

Of course, after all that, you need to work out which card can give you the raid levels and drive connections you are looking for, but that becomes the easy part.

So … back the heading … if you’re not sure, call :-)

Ciao
Neil

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So how do you put that together?

May 4, 2012

Had a call from a customer who had already purchased a bunch of hardware and wanted to know how to put it together. While this is not my ideal way to go about things (generally I like to talk to people “before” they spend any money), the deed had been done so I needed to explain my best thoughts on how to put this all together.

The explanation was not going well. I wanted the customer to create a hybrid raid, and my explanation just wasn’t sinking in. I thought to myself – I’ve written something about this somewhere … now where did I put those files?

It finally occurred to me that I wrote some stuff for marketing who put it all in a whitepaper and stuck it on our web. So I took the customer past ET (see if you can tell me what I mean by that), and through to the “new whitepaper” on hybrid raid on our website.

I completely ignored the first page (because I didn’t write that) and moved to the following pages and their neat little diagrams of how to mix and match SSD and spinning media to get the best combinations of performance, capacity, cost etc. Worked like a treat. As the old saying goes, a picture is worth a thousand words.

So take a look at the whitepaper – I’m not going to give you the link because I want you to work out my ET joke (if in fact you are old enough).

Ciao
Neil

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Just how fast can things go?

May 4, 2012

I spent some time last month at Intel’s IDF in Beijing. Doing the meet and greet with all the great Chinese customers, resellers, integrators etc. They really are a nice bunch of people and I love Beijing at that time of year (it’s considerably warmer than December).

On the Adaptec stand we had all of our current products, and something a little special. A PCIe 3 prototype product demonstrating PMC’s SRCv chip: 24-native SAS ports, PCIe Gen 3.0 etc etc. We borrowed 16 SATA SSD’s (Pulsar XT) from Seagate, scrounged a server from our friends at Karmen (or should I say my good friends at Karmen did the scrounging for me) – and we cobbled the whole thing together in 20 minutes just (and I mean just) before the show.

A simple raid0 across the 16 drives using all defaults (256kb stripe size etc). slapped Windows 2008 R2 SP1 on it, formatted the disk and ran up iometer. I like to do this because it shows real world speed – yes I can get better performance running on a raw disk but that’s just hocus pocus when it comes to numbers.

So … slap the whole thing together, run up iometer on a 100% 256kb sequential read – simple. Then sit back and watch whether this is in fact going to work at all. Holy suffering catfish Batman – 6030mb per second read speed. Blink, double-check, run iometer again – yep, 6030mb per second.

Is this a secret? The product running the whole show certainly is. The chip powering it is not (it’s a publicly released product) and the results – well to every person who picked their jaw up off the ground and stopped to question us intently about just what we were doing – no it’s not a secret.

It’s just one hell of a performance number.

Ciao
Neil

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