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 [...]

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 [...]

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 [...]

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.

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.

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 : )

Does my midrange look big in this?

IDC defines three categories of external disk. The midrange market leaders are EMC, Netapp and IBM (followed by Dell and HP with both slipping slightly over the last 12 months). Netapp is almost entirely a midrange business, while EMC and IBM are the market leaders in highend. Over the last 4 quarters midrange has accounted [...]

One size does not necessarily fit all…

IBM SAN Volume Controller & HDS USP It’s been 7 years since IBM released SAN Volume Controller and brought multi-vendor storage virtualization and volume mobility to the mainstream market. SVC provides virtualization in the storage network layer, rather than within a disk system, and IBM has shipped more than 10,000 I/O groups (SVC node pairs). [...]

When Space, Time & Vendor Charges Collide…

Well the whole snapshot and replication thing got me thinking about vendor licensing. Licensing is a way to get a return on one’s R&D, it doesn’t really matter whether customers pay x for hardware and y for software, or x+y for the hardware ‘solution’ and zero for software functions etc, as long as the vendor [...]

Is it time for the Enterprise Linux Server?

IBM’s Z10 Enterprise Linux Server is an interesting alternative to a large-scale VMware deployment. Essentially, any Linux workload that is a good fit for being virtualised with Vmware is a good fit for being virtualised on Z10.

Hey this Gibibyte stuff is really taking off!

So you know we’re making progress on the binary units thing (see my post entitled “How many fingers am I holding up“) when Piratebay.org starts using GiB… 7,368,671,232  Bytes   =    7.37 GB     or    6.86 GiB Now if we can only get the IT vendor community to consistently follow Piratebay’s excellent [...]

How many fingers am I holding up?

The base2 Vs base10 nett capacity question is an interesting one. It remains a place of confusion for customers and that’s not surprising as it remains a place of confusion for vendors also.

IBM Easy Tier with SATA and SSD

IBM has just published a very cool 33,000 IOPS SPC-1 benchmark result for the DS8000 using 96 x SATA and 16 x SSDs (not a FC drive in sight!) and with a max latency well under 5ms. I’m impressed. This is a great piece of engineering. Easy Tier was left to automatically learn the SPC-1 [...]

Application-aware snapshots for IBM Storage

Something strange has happened. IBM’s Tivoli group has produced some low-priced high-value storage software that’s easy to understand and easy to use! FlashCopy Manager provides fast application-aware backups and restores, leveraging the snapshot features of IBM storage systems.

Low-Cost DR with Split Cluster SVC

Ever since IBM’s SAN Volume Controller was first delivered back in 2003 folks have been looking at the 2n cluster nodes and wanting to separate them physically to achieve a degree of disaster recovery. This is generally referred to as  ‘split i/o group’ or ‘split cluster’. For this to be a good idea, two additional [...]