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NYRO Technologies has announced their new NXRAID product for Mac OS X, and offers a beta version for a free download. It is the latest in a series of announcements about future RAID products. What does that mean for you? Well, it means that progress is being made toward making Mac OS X a functional OS for video and file-serving, and toward making it more reliable for data-storage. If all that you do is casual word processing and web-browsing, you probably get along just fine right now, but if your work demands raw speed or your files are especially important, you're likely to need a RAID at some point. I have been trying to find a viable OS X RAID solution for ages. It would make life a lot easier for me if one of them worked. Nothing has proven itself yet, but there is a lot of stuff out there and eventually, one of them has to work... at least I hope so. As briefly as I can make the case in a single rant, here is the situation with RAIDs under Mac OS X... A QUICK PRIMER ON RAID RAID stands for Redundant Array of Independent Disks. RAID-ing your drives describes any of several ways of organizing your hard drives in order to combine their storage-capacity, to use one or more drives as a backup for another, or generally just to speed up access by writing portions of your data across multiple drives at once. The most common RAID configurations are RAID-0, RAID-1 and RAID-5. Bare-bones definitions:
RAID-0: sharing data across multiple drives in order to get a speed-boost
RAID-1: one drive becomes a redundant backup for the other (also called "mirroring")
RAID 5: sharing data across multiple drives in such a way that you get a speed-boost and also the added benefit that should one drive fail, its data can be reconstructed from information on the other drives. Each of those kinds of RAIDs may in-turn be set up in one of two ways. Software-RAIDs are configured and controlled through a software interface that in-turn must run on your computer and relies on your computer to execute many functions. Hardware-RAIDs rely on an independent controller and require very limited resources from your computer. Both hardware RAIDs and Software RAIDs require some sort of interface through which the drives are connected to your computer -- typically this is a PCI card, but in some cases they can connect to an existing SCSI or FireWire port. When would you want to set up a RAID? RAIDs are used in any place where either the speed of access or integrity of the data is important. Common places to find RAIDs might be in video-production where large multimedia files are generated; in network-servers to deal with the simultaneous demands of many users; or even on your own desktop, where a mirrored drive provides a cheap backup of your main hard drive. I support users who work with video, whose use stresses file-servers to their maximum abilities, and whose fortunes are at the mercy of their data-integrity. As a result, I am very interested in keeping up with the latest RAID software and hardware. Under Mac OS 9 there are myriad RAID solutions. Some of them are notoriously bad, while others have very solid reputations. Anyone researching RAIDs for Mac OS 9 will easily find a great deal of information and innumerable options. But those options don't translate well to OS X. Here's what my recent experience has brought to light:
INTERFACE CARDS
Getting into the nitty-gritty of the SCSI vs IDE debate isn't what this rant is about. Accept for the moment that SCSI is at the heart of any fast and dependable RAID. The situation is better than it was when Mac OS X first shipped and might not successfully install on a system with a SCSI card. The ongoing problem is simply that Apple has not made SCSI support a priority and it shows in the fact that compatible SCSI cards are only just appearing. Atto has released OS X compatible versions of their new SCSI cards and firmware-updates to make many older cards compatible, but there are stability-issues with different G3 and G4 motherboards and what works on one Mac might not work on the Mac next to it. Even so, Atto offers the best SCSI solutions and support out there for OS X. (Adaptec's OS X drivers just don't work for me -- if anyone has successfully RAIDed drives with the Adaptec drivers present, please post your solution). Obviously, your interface card has to work reliably before you can set up a reliable RAID.
APPLE DISK UTILITY
As of this past March, Apple has kindly added RAID-0 and RAID-1 abilities to their Disk Utility for OS X. RAID volumes initialized with this software cause crashes and hangs when I try to use it. As an added complication, volumes created with this software won't appear under Mac OS 9. Since some disk-repair utilites (notably DiskWarrior) require OS 9 to run, this is a serious problem.
OTHER SOFTWARE PRODUCTS
The only third-party Software RAID product for OS X that's actually shipping, Atto's ExpressStripe has major limitations (It only makes RAID-0 volumes and it seems to have a max of 4 drives in the RAID) and when I tried it, my G4 450 desktop system intermittently booted into a gray screen until I initialized the drives and ditched the Atto driver. The Atto RAID volumes aren't visible in OS 9 without a (buggy) system extension. Other companies like Charismac and SoftRAID make RAID software their primary business. Yet more than a year after Mac OS X 10.0 shipped, they haven't been able to release a final product. When I speak to their representatives, they mention that MacWorld Expo is just around the corner, so we may get some pleasant surprises from them in the near future.
THE HARDWARE RAID
Hardware RAID systems are one gray area in the SCSI/IDE debate. For small offices and limited digital video editing purposes, external hardware RAIDs that use IDE devices may be alright. They can't cope with the bandwidth demands of a busy server or uncompressed NTSC video, but some of them can use RAID-5 to minimize data loss from the high failure-rate of their IDE drives and they are considerably cheaper than SCSI. I haven't found a hardware RAID box that works reliably under OS X, regardless of the interface card that it's hooked up to and regardless of whether it uses SCSI or IDE drives. This may be the cards at fault, but I suspect problems in the RAID software/firmware. I constantly speak to vendors working to isolate these bugs and I have confidence that external hardware RAIDs will be a reliable option by the end of the year. ATA RAID cards are totally flaky under OS X, and I wouldn't use them for client-data even under OS 9 because they're low-end consumer products and the drives fail. Where my clients have them, I will not support them. Even under OS 9, RAIDs based on cheap ATA RAID cards only support RAID-0 or RAID-1. I haven't tried FireWire RAIDs, but to me the whole idea of making a RAID with a maximum sustained write speed of 18 MBps and read-speed of 38 MBps is just silly (Don't tell me that FireWire is 50 MBps -- try it. And on a Powerbook, it's less than half of that. Real-world tests.) Plus, you still have unproven drivers. Plus hooking up FireWire devices to OS X servers seems to make them unstable.
WILL THE XSERVE CHANGE THE EQUATION?
The short answer is, "no." XServe has 3 flaws as far as its RAID-options go. First, it only has native support for ATA RAIDs, and as I stated above, ATA is an inferior platform. Additionally, it relies on Apple's Disk Utility to create its RAID -- software which has serious flaws. Finally, it doesn't support RAID-5, which is a horrible oversight, considering that the businesses that it is aimed at are precisely the kinds of businesses that are most likely to need the speed and security of RAID-5. That's not to say that XServe won't be up to the challenge in the future. Third-parties are eventually going to get their software and hardware to work under OS X and Apple has indicated that they will support RAID-5 in their FibreChannel storage solution due out later this year, and designed to integrate with the XServe.
IN CLOSING
I know that I sometimes come off as being very harsh toward Mac OS X. I'm growing to like it more as I use it more, but I still can't deploy it widely because there's so much to fix and so much that's waiting for third-party support. RAIDs are another not-ready-for-prime-time part of OS X. It is a ray of hope that there are new products being developed for making RAIDs under OS X. The problem is that none of them quite works right here and right now. That's the state of many things with OS X. It's still a new operating system. It will probably take a few more years before everything works as well under OS X as it did under OS 8 and 9. That's just the way things are.
OLD COMMENTS
Wow. Should I move my B/W G3 to OS X? I was going to do it thist month, but I have an old 8-gig striped RAID that I want to keep and I do SCSI tape backups. Will any of that work under OS X? Posted by: Billy on July 5, 2002 02:24 AM
If you use Retrospect then you can upgrade to an OS X version that should work with your tape drive (check with Dantz to see if it's compatible). The RAID is another matter. You will have to re-initialize your RAID volumes to get them to mount under OS X. RAID drivers from earlier versions of the OS don't mount properly under OS X. Also, your SCSI card will need the latest firmware and drivers available and if there aren't OS X upgrades for the card then you will have to buy a new one. I can say that you will probably be able to get your RAID up and running under OS X 10.1.5, but I am far from certain. IMHO, Apple has not planned future software updates for G3s. My advice is that you can probably upgrade your Mac to OS X and have it working okay, but you will be better off saving up your money now to buy a G4 next year. Your G3 will not be able to get the most out of OS X. Jaguar -- the next major upgrade to OS X -- will have a new graphics engine that is optimized for G4s with AGP video cards that have at least 32 megs of DDR video RAM. Posted by: Stacey on July 5, 2002 07:42 AM
>>Your G3 will not be able to get the most out of OS X.
>> I run OS X on my G3 iBook!! Posted by: Zed on July 5, 2002 10:14 AM
>>I run OS X on my G3 iBook!!
>> You will not be able to take full advantage of OS X 10.2. According to Apple's tech-notes, Quartz Extreme -- the new accelerated graphics engine for OS X 10.2 and above -- will not run at all with less than AGP 2 Radeon video with 16 megs VRAM and will not run "optimally" with less than 32 megs of VRAM. Older iBooks that have 8 megs of VRAM will not be able to run Quartz Extreme, so they won't see major speed improvements in OS X 10.2. The newest iBooks can run Quartz Extreme, but won't run it "optimally." Even older TiBooks won't be able to take full advantage of OS X 10.2 because they do not have the appropriate video hardware. Posted by: Stacey on July 5, 2002 06:43 PM
>>so they won't see major speed improvements in OS X 10.2<< Looking over officially realeased info and leaked info (rumor) on 10.2, you will see moderate to large speed improvements even if you can't use Quartz Extreme. Optimizations in 10.2 (Jaguar) are not limited to Quartz Extreme. How much of an improvement without QExt. won't be known until 10.2 is released. Posted by: Lou on July 9, 2002 10:30 AM
As with OS X 10.1.5, there will be speed improvements in start-up and application-launch times, regardless of whether you run it on a G3 or a G4. In my observations, OS X 10.2 is still considerably slower overall than OS 9 without Quartz Extreme. In the developer-preview version of Jaguar that I have seen, Quartz Extreme made the OS very fast. Classic applications didn't see significant speed boosts and were crash-prone, but both Carbon and Cocoa applications seemed to speed up such that OS X was subjectively just as fast as OS 9. I haven't done a stopwatch-test yet. When I get the chance to spend a few days on 10.2 or if I see a website with stats, I'll post it. I think that if you are running an older Mac without the proper video card, you will be green with envy when you see the performance of 10.2 on Apple's recent models. There are upgrades available for G3 desktops that will allow you to take (nearly) full advantage of 10.2, but there are other factors to consider. The writing is on the wall for G3 computers. ThinkSecret has suggested that G3 iMacs will be phased out by August. That leaves the iBook as the only G3-based Apple computer. One might ask whether these circumstances suggest that Apple will devote a lot of resources toward making OS X work well with G3 chips. Posted by: Dirty on July 12, 2002 12:05 PM
>>The writing is on the wall for G3 computers Don't you ever write about the good things about Macs, Dirty? (^.^) Posted by: Miss Lee on July 12, 2002 02:14 PM
>>Don't you ever write about the good things about Macs, Dirty? You want cynical? Watch Apple's stock price if rumors are accurate and Steve fails to introduce new desktop Macs at Macworld... Urgh! I'm a stockholder!!! Posted by: Dirty on July 12, 2002 08:30 PM
Go to this URL for a discussion on the speed of Jaguar on various systems: http://dealmac.com/forums/read.html?f=1&i=806282&t=806282 Posted by: Andrew on July 14, 2002 09:55 PM
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