Amazing RAID, how sweet the storage....

….that saved a kvetcher like me…. Last summer, EDN published an editorial I wrote after the 2004 Storage Visions conference, where I commented on the burgeoning capacities and plummeting cost-per-GByte of HDD media, the increasing disconnect between that capacity and the storage needs of mainstream PC users, and the resultant HDD vendor focus on beyond-the-PC applications. One other key outcome of that disconnect that I want to highlight here involves RAID, a technology which I've personally embraced. If the vendors can't sell you one big HDD, the thought process goes, maybe they can instead sell you two or more smaller HDDs, thereby still optimally utilizing their available production capacity.

Content creation professionals, especially those in the videography business, have long understood the performance-boosting benefits of 'striping' a large file access across multiple drive platters. The other significant segment of the PC-using public that has to date embraced RAID 0 are the extreme overclockers, under the perhaps mistaken belief that a multi-drive performance-tuned array would boost game and level load speeds. For the majority of PC users, though, I believe that a redundant RAID 1 array is the more attractive two-drive configuration, since the value of the information stored on HDDs is skyrocketing in the modern era of digital audio and still/video photography.

RAID setups used to be cumbersome and expensive, involving slot-gobbling PCI add-in cards, wide airflow-blocking cables, and buggy software drivers. Intel and its core logic competitors have made things dramatically simpler in this past year or so, however; SATA eliminates the bulky cabling of the PATA past, point-to-point connectivity between the core logic and HDD optimizes per-connection bandwidth, software-based RAID support is built into the chipsets, and CPUs are fast enough that soft RAID doesn't noticeably performance-strap the system. Intel's Matrix Storage Technology is particularly flexible; within a single two-drive array you can set up multiple partition pairs, some RAID 0 and others RAID 1. And with SATA support built into Intel's latest i915 (aka 'Alviso') mobile chipset found in the Sonoma platform, the emergence of RAID in laptops is only a matter of time, since three 1.8" HDDs take up roughly the same total cubic area as a single 2.5" predecessor.

I've been running a RAID 1 array on my desktop Windows system ever since I first built it up. The version of the ICH5 southbridge chip that came on the PowerEdge 400SC's motherboard doesn't support RAID, so I added a Silicon Image SiI 3112 SATA RAID controller PCI card. Aside from getting a bogus 'RAID 1 set is in a Sync state….a rebuild will occur' message every time I bring the system out of Hibernation (the system never actually rebuilds; a driver uprev might fix this annoyance but I haven't bothered) the setup is rock-solid and I'm quite pleased.

On my PowerMac, the path to RAID 1 was a bit more complicated. OS 10.3 comes with built-in RAID support, but you can only set up RAID 0 and 1 arrays on fresh HDDs. I already had an O/S and application build on the 250GB Maxtor drive that came with my system, a drive that I wanted to migrate to a RAID 1 configuration. SoftRAID came to the rescue; the company actually developed the RAID utilities that Apple bundles with OS 10.3, allaying my compatibility concerns, and SoftRAID 3 supports conversion of existing images to RAID 0 and 1 configurations. The instructions weren't the most clear or complete I've ever read (the company promises to soon fix this shortcoming) but so far my resulting RAID 1 setup has, again, been rock-solid. My next step is to add a separate two-drive RAID 0 array for high-res video editing purposes, combining SoftRAID with a G5Jam PowerMac enclosure modification system from WiebeTech (which includes a SATA card), along with, if necessary, a SATA RAID card from FirmTek or Sonnet Technologies.

I even have a two-drive 160GB RAID 1 configuration running on my NAS; specifically, my NDAS. Latest revisions of Ximeta's NetDisk software drivers support RAID 1 mirroring, along with JBOD and RAID 0 aggregation (but only under Win2K and XP)….of a sort. Both drives need to be blank to start, and automatic RAID 1 rebuild doesn't occur if they get out of sync (as would be the case if one of them crashed). The Linux build that comes standard with my dual-drive Toshiba Magnia SG10 network appliance doesn't support RAID, according to Webmin, but eventually I hope to find the time to try out alternative ClarkConnect,e-smith, and NetMAX Linux distros, currently in my possession, on the platform.

Have you implemented your own RAID setup? Why, and what's your experience been? Thinking of doing one, or did consider it but eventually discarded the idea? Please share your thoughts with me and the other denizens of Brian's Brain.