Inside System Storage -- by Tony Pearson

Continuing this week's discussion on IBM announcements, today I'll cover our integrated systems.

The problem with spreading out these announcements across several days' worth of blog posts is that others beat you to the punch. Fellow blogger Richard Swain (IBM) has his post [Move that File], and TechTarget's Dave Raffo has an article titled [ "IBM SONAS gains policy-driven tiering, gateway to IBM XIV Storage System"].

By combining multiple components into a single "integrated system", IBM can offer a blended disk-and-tape storage solutions. This provides the best of both worlds, high speed access using disk, while providing lower costs and more energy efficiency with tape. According to a study by the Clipper Group, tape can be 23 times less expensive than disk over a 5 year total cost of ownership (TCO).

The two we introduced recently were the [IBM Information Archive] and the Scale-Out Network Attached Storage (SONAS). This week, IBM announced some enhancements as SONAS v1.1.1 release. SONAS is the productized version of IBM's Scale-Out File Services (SoFS), which I discussed in my posts [Area Rugs versus Wall-to-Wall Carpeting] and [More details about IBM's Clustered Scalable NAS].

ILM and HSM data movement

I have covered Information Lifecycle Management several times in this post, including my posts [ILM for my iPod], [Times a Million], and [Using ILM to Save Trees], to name a few.

I've also covered Hierarchical Storage Management, such as my post [Seven Tiers of Storage at ABN Amro], and my role as lead architect for DFSMS on z/OS in general, and DFSMShsm in particular.

However, some explanation might be warranted in the use of these two terms in regards to SONAS. In this case, ILM refers to policy-based file placement, movement and expiration on internal disk pools. This is actually a GPFS feature that has existed for some time, and was tested to work in this new configuration. Files can be individually placed on either SAS (15K RPM) or SATA (7200 RPM) drives. Policies can be written to move them from SAS to SATA based on size, age and days non-referenced. HSM is also a form of ILM, in that it moves data from SONAS disk to external storage pools managed by IBM Tivoli Storage Manager. A small stub is left behind in the GPFS file system indicating the file has been "migrated". Any reference to read or update this file will cause the file to be "recalled" back from TSM to SONAS for processing. The external storage pools can be disk, tape or any other media supported by TSM. Some estimate that as much as 60 to 80 percent of files on NAS have low reference and should be stored on tape instead of disk, and now SONAS with HSM makes that possible.

This distinction allows the ILM movement to be done internally, within GPFS, and the HSM movement to be done externally, via TSM. Both ILM and HSM movement take advantage of the GPFS high-speed policy engine, which can process 10 million files per node, run in parallel across all interface nodes. Note that TSM is not required for ILM movement. In effect, SONAS brings the policy-based management features of DFSMS for z/OS mainframe to all the rest of the operating systems that access SONAS.

HTTP and NIS support

In addition to NFS v2, NFS v3, and CIFS, the SONAS v1.1.1 adds the HTTP protocol. Over time, IBM plans to add more protocols in subsequent releases. Let me know which protocols you are interested in, so I can pass that along to the architects designing future releases!

SONAS v1.1.1 also adds support for Network Information Service (NIS), a client/server based model for user administration. In SONAS, NIS is used for netgroup and ID mapping only. Authentication is done via Active Directory, LDAP or Samba PDC.

Asynchronous Replication

SONAS already had synchronous replication, which was limited in distance. Now, SONAS v1.1.1 provides asynchronous replication, using rsync, at the file level. This is done over Wide Area Network (WAN) across to any other SONAS at any distance.

Hardware enhancements

Interface modules can now be configured with either 64GB or 128GB of cache. Storage now supports both 450GB and 600GB SAS (15K RPM) and both 1TB and 2TB SATA (7200 RPM) drives. However, at this time, an entire 60-drive drawer must be either all one type of SAS or all one type of SATA. I have been pushing the architects to allow each 10-pack RAID rank to be independently selectable. For now, a storage pod can have 240 drives, 60 drives of each type of disk, to provide four different tiers of storage. You can have up to 30 storage pods per SONAS, for a total of 7200 drives.

An alternative to internal drawers of disk is a new "Gateway" iRPQ that allows the two storage nodes of a SONAS storage pod to connect via Fibre Channel to one or two XIV disk systems. You cannot mix and match, a storage pod is either all internal disk, or all external XIV. A SONAS gateway combined with external XIV is referred to as a "Smart Business Storage Cloud" (SBSC), which can be configured off premises and managed by third-party personnel so your IT staff can focus on other things.

See the Announcement Letters for the SONAS [hardware] and [software] for more details.

For those who are wondering how this positions against IBM's other NAS solution, the IBM System Storage N series, the rule of thumb is simple. If your capacity needs can be satisfied with a single N series box per location, use that. If not, consider SONAS instead. For those with non-IBM NAS filers that realize now that SONAS is a better approach, IBM offers migration services.

Both the Information Archive and the SONAS can be accessed from z/OS or Linux on System z mainframe, from "IBM i", AIX and Linux on POWER systems, all x86-based operating systems that run on System x servers, as well as any non-IBM server that has a supported NAS client.

technorati tags: , IBM, Announcements, SONAS, SoFS, Information+Archive, Richard Swain, TechTarget, ILM, HSM, storage tiers, GPFS, TSM, HTTP, NIS, TSM, NAS, iRPQ, XIV, SBSC, z/OS, Linux, AIX