Letter from America

I’m currently in Los Gatos, California for a month learning all about the inner workings of SAN Volume Controller and Storwize V7000 copy services. I have my next storage post planned for June 4th or 5th, and once the new SVC and Storwize V7000 Copy Services Redbook is published I might also post some personal [...]

Drive Rebuilds Continued…

I’ve been too busy to blog recently, but I have just paused long enough to add a significant update regarding IBM Storwize V7000 drive rebuild times to my earlier post on RAID rebuild times. Rather than start a new post I thought it best to keep it all together in the one place, so I [...]

FCIP Routers – A Best Practice Design Tip

Many years ago a Glaswegian friend of mine quoted someone as saying that the 1981 anti-apartheid protests in New Zealand (South African rugby tour) showed that New Zealand was not just a floating Surrey as some had previously suspected. While the Surrey reference might be lost on those not from England, I can tell you [...]

Easy Tier is even better than we thought!

IBM storage architects and IBM Business Partners are encouraged to use Disk Magic to model performance when recommending disk systems to meet a customer requirement. Recently v9.1 of Disk magic was released and it listed nine changes from v9. This little gem was one of them: “The Easy Tier predefined Skew Levels have been updated based [...]

Hu’s on first, Tony’s on second, I Don’t Know’s on third

This post started life earlier this year as a post on the death of RAID-5 being signaled by the arrival of 3TB drives. The point being that you can’t afford to be exposed to a second drive failure for 2 or 3 whole days especially given the stress those drives are under during that rebuild [...]

XIV Gen3 Sequential Performance

Big Data can take a variety of forms but what better way to get a feeling for the performance of a big data storage system than using a standard audited benchmark to measure large file processing, large query processing, and video streaming. From the www.storageperformance.org website: “SPC-2 consists of three distinct workloads designed to demonstrate [...]

NAS Robot Wars

The new Storwize V7000 Unified (Storwize V7000U) enhancements mean that IBM’s common NAS software stack (first seen in SONAS) for CIFS/NFS/FTP/HTTP/SCP is now deployed into the midrange. Translating that into simpler language: IBM is now doing its own mid-range NAS/Block Unified disk systems. Anyone who has followed the SONAS product (and my posts on said [...]

A Small Challenge with NAS Gateways

SAN Volume Controller Late in 2010, Netapp quietly announced they were not planning to support V Series (and by extension IBM N Series NAS Gateways) to be used with any recent version of IBM’s SAN Volume Controller. This was discussed more fully on the Netapp communities forum (you’ll need to create a login) and the reason given [...]

World’s most affordable high-function 500TB+ block I/O disk solution

Gotta love this price-optimized solution for two tier disk… (plus Easy Tier automatic SSD read/write tiering). This is possibly the most affordable high-function 500TB+ disk solution on the planet… and it all fits into only 32u of rack space! Yeah I know it’s a completely arbitrary solution, but it does show what’s possible when you [...]

Nearline-SAS: Who Dares Wins

Maybe you think NL-SAS is old news and it’s already swept SATA aside? Well if you check out the specs on FAS, Isilon, 3PAR, or VMAX, or even the monolithic VSP, you will see that they all list SATA drives, not NL-SAS on their spec sheets. Of the serious contenders, it seems that only VNX, [...]

Storwize V7000 four-fold Scalability takes on VMAX & 3PAR

IBM recently announced that two Storwize V7000 systems could be clustered, in pretty much exactly the same way that two iogroups can be clustered in a SAN Volume Controller environment. Clustering two Storwize V7000s creates a system with up to 480 drives and any of the paired controllers can access any of the storage pools. [...]

Am I boring you? Full stripe writes and other complexity…

In 1978 IBM employee Norman Ken Ouchi was awarded patent 4092732 for a “System for recovering data stored in failed memory unit.” Technology that would later be known as RAID 5 with full stripe writes. Hands up who’s still doing that or its RAID6 derivative 33 years later? I have a particular distaste for technologies [...]

You can’t always get what you want

There have been a raft of new storage efficiency elements brought to market in the last few years, but what has become obvious is that you can’t yet get it all in one product.

Maximum Fibre Channel Distances

Just a quick hit and run blog post for today… This table authored by Karl Hohenauer just came into my inbox. With the changes in cable quality (OM3, OM4) the supported fibre channel distances have confused a few people, so this will be a good reference doc to remember.

Where Should I Shove This Solid State Drive?

Everyone agrees that enterprise-class SSDs from companies like STEC Inc are fast, and cool, and pretty nice. Most people also realise that SSDs are an order of magnitude more expensive than SAS drives, and that there is no expectation that this will change dramatically within the next 5 years. This means we have to figure out [...]

Storwize V7000 Vs the Rest – a Quick SPC-1 Performance Roundup

This post is in response to the discussion around my recent Easy Tier performance post.

Storwize V7000 Easy Tier: SATA RAID10 Vs SAS RAID6

When IBM released it’s SPC-1 Easy Tier benchmark on DS8000 earlier this year, it was done with SATA RAID10 and SSD RAID10, so when we announced Storwize V7000 with Easy Tier for the midrange, the natural assumption was to pair SATA RAID10 and SSD RAID10 again. But it seems to me that 600GB SAS RAID6 [...]

Exploiting the Intelligence of Inventors

In Tracey Kidder’s book “Soul of a New Machine” I recall Data General’s Tom West as saying that the design that the team at Data General came up with for the MV/8000 minicomputer was so complex that he was worried. He had a friend who had just purchased a first run Digital Equipment Corp VAX, [...]

Quality of Service on SAN Volume Controller & Storwize V7000

I learned something new recently. SVC has QoS, and has had it for quite some time (maybe since day 1?).

IBM’s New Midrange with Easy Tier & External Virtualization

Yes, IBM has announced a new midrange virtualized disk system, the Storwize V7000. A veritable CLARiiON-killer : )

Choice or Clutter?

Vendors often struggle to be strong in all market segments and address the broad range of customer requirements with a limited range of products. Products that fit well into one segment don’t always translate well to others, especially when trying to bridge both midrange and enterprise requirements.