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View Full Version : Internal H/W RAID 0 on a 7500 - HOWWWW???



maXXed out
02-21-2002, 08:59 PM
Please see my signature for system configuration...
But basically, I've got a 7500 with an Adaptec 2940UW (single) card.
I'm REALLY happy with the performance of the new LVD Cheetah on the Adaptec
card*, but WANT to set up a 0 level striped dual cheetah array. But I DON'T
want to use softraid or any software tools. I want REAL hardware raid and I want it internally. I've read numerous FAQs on this site and on XLR8YOURMAC, but can't really seem to figure out how to do it.

QUESTIONS:
A. IS IT POSSIBLE??
B. Will I need a dual channel card (ultra2) to achieve this.Clearly the adaptec card is up to 40MB/sec performance on a single channel. Can I still use this card??


* I'm getting 37MB/sec sustained writes and 32MB/sec sustained reads on FWB HD
tool kit's bench test (max 512K blocks mixed)

------------------
Mac 7500
Sonnet 300MHz G3
Number Nine Imagine 128
640MB ram
Adaptec 2940UW
dual Sony GDM17SE1 monitors
Cheetah ST34501
Cheetah ST39204LW

dragon_x
02-21-2002, 09:36 PM
A. Yes, but then just about anything is possible in theory http://macgurus.com/infopop/emoticons/icon_smile.gif
B. No. Not necessarily.

OK Now the real answers are a bit more involved.

I do not see any real advantage going to a hardware RAID setup on your system. There might be some out there - they might not even cost an ARM AND A LEG but what about support? Are you going to get any real support and/or stability with a hardware setup? Probably not. Stability is key since you are essentially doubling the odds of a drive failure - but then all drives will fail eventually.

I would recommend you try to move to MacOS X (10.1 or higher) and run with an Adaptec 2940U2b. This has some support in X since it was an OEM card for many of Apple's beigeG3's (gossamer) and B&WG3's (yosemite). I had one running nicely in my YoseG3/500 with X - but then that is a supported system. The 604 systems were originally supported (9500/9600) under RHAPSODY and your board is very similar. You will probably need to get an ATI RAGE128 (ORION), NEXUS 32MB or RADEON PCI (old ROM is probably the best) and you DISK I/O will fly in X! http://macgurus.com/infopop/emoticons/icon_biggrin.gif

Assuming you can get it all to work well. Dual displays are not supported so well and you might have to use the built-in video or at least plug in an adaptor (to fake the system out).

You could get a B&WG3 for cheap - it would probably be CHEAPER and EASIER than getting a HARDWARE RAID.

Single channel Ultra2 LVD cards are best for vintage PCI macs like yours. The Miles U2W (they are always wide http://macgurus.com/infopop/emoticons/icon_wink.gif) Is a great card that will give you around 40 ~ 79MB/s bandwidth depending on drives and what you are doing (I think write speeds may be limited to 40 or 50MB/s). Dual channel Ultra2s would be waste IMHO and I am not sure how well they are supported anyway. I think Adaptec's SPEEDFLEX kinda fizzled.

Maybe you think software is bad because MS and other companies push a lot of crud onto market? They do but the SoftRAID guys are VERY careful and detail oriented about their drivers and software. That is why it is not out already and there other 'solutions' that are still in the beta stage - of course they did not advertise it as a beta (maybe it should have been alpha?).

To have a hardware raid you simply need a controller (interface) that will make however many drives in whatever configuration appear as a single drive. Of course this is much easier said than done and the PROs often spends months testing their setups rigorously - since they often go in systems than NEED to run 24/7 365+ and they WILL have hell to pay if anything goes wrong.

SoftRAID comes with the MilesU2W - along with a quality twisted pair LVD cable + term. Its a good deal!

------------------
The Cost Of Freedom:
Every bit of energy.
Every ounce of courage.
Every drop of blood.

Sic Semper Tyranus!

ricks
02-22-2002, 12:14 AM
To add one thing to what d_x had to say,

The only difference between hardware raid and software raid is where the controlling is done. A decent hardware raid card (other than ATA raid) has it's own processor, usually an x86 Intel or a IBM risc cpu chip setup to do just the job of parceling out the data to the various drives. I have neveer seen a hardware raid card that didn't support RAID0, RAID1, RAID0+1, RAID3 and RAID5. They are very flexible and can be just as finicky as software raid can be.

Wait till you see what one costs.

Software raid for scsi and OS9 is really quite mature, the cpu overhead is very low and the speed of an array can easily saturate a PCI bus. That's as fast as it gets no matter what type of raid you install.

See the results in past raid forum posts on 2,4,6 or even 8 drive Cheetah raids, maxing out the bus with 4 drives is not hard and adding more means no matter what you throw at the array you will never drop below saturation. My 4 drive AtlasIII array also reaches saturation of the bus in reads while coming close on the writes. Your PCI bus will not allow those kinds of max numbers on a 7500.

You also have a choice to go with hardware ATA133 RAID0. This is cheap and easy, the drives appear as one to the computer and have no overhead for the cpu at all.

You can read about ATA133 raid installs and performance at: http://www.barefeats.com/hard21.html http://www.xlr8yourmac.com/IDE/IDE_RAID/acard_ata133_raid_report.html

SoftRAID is the fastest of the fast in SCSI raid for OS9 and a couple of Cheetahs or Barracuds.

Hope that helps some.

Rick

maXXed out
02-22-2002, 01:24 AM
Thanks. I think that fairly addresses my questions. I'd actually never really SEEN any info on hardware RAID cards/controllers... only software. I'd assumed there was nothing like that necessary... that it was a cabling and SCSI ID issue somehow. Black magic to me.

Anyway, I'm just a little bit apprehensive about software RAID in case of a major crash... I'm worried I'd NEVER get booted again off a Mac OS install CD! As it stands now with the drives I have recovering from crashes or updated MacOS is hard enough!!! I just updated from 7.5.5 (EEKS!) to 8.6. Old School, huh?? I figure if you've put alot of work into a holistic software system (with your OS and apps) - just stick with it if it works, right?? If you upgrade one thing, you have to upgrade a bunch of other stuff and then you're into thousands of dollars! (I just updated one of my CAD programs for $1000 - hence using 8.6!!) Anyway, BUT I DIGRESS...

SO here's the deal...
Given this configuration, I'm going to forget about the H/W RAID setup. If I could have done it for less than $400 then I would have (still might consider softraid when I find out more about it). Is there anything in the middle?

How can I get the best performance possible for my 7500 using Cheetah LVDs and my five year old 2940 card?? Straight up (non-striped) X15s I guess??? I know I shouldn't be so gluttonous. I'm pretty ecstatic that my 7500 can do what it can. 36-37 MB/sec writes are pretty damn good considering. I'd just LOVE to be able to open a 150MB Photoshop file in three seconds!!!


Anyway, THANKS so much for the helpful info!

------------------
Mac 7500
Sonnet 300MHz G3
Number Nine Imagine 128
640MB ram
Adaptec 2940UW
dual Sony GDM17SE1 monitors
Cheetah ST34501
Cheetah ST39204LW

maXXed out
02-22-2002, 01:29 AM
PS...

Yeah... I KNOW I'm due for a CPU mainframe upgrade REAL soon. I'll probably go for (which model was it... that was the first model with 64bit memory bus and 64bit PCI????). Was that one of the B&Ws?? But I just wanted to get the 7500 into the fastest configuration possible before I stop tinkering with it.

TZ
02-22-2002, 03:26 AM
The B&W is seriously flawed in more ways than you can imagine (unless you've lived with one for couple years) and QSG4/733's are $1299 now. Save your money on the X15 which is over-kill, the 10k Cheetahs are more than enough with the "...406LW" models (current) that have 50-63MB/s write.

The new IBM 120GXP 40GB is reviewed on www.storagereview.com (http://www.storagereview.com) and comes in strong 42MB/s (outer tracks).

Gregory

rwm
02-22-2002, 01:30 PM
Gregory is right. I have tweaked my 7500 and it kicks butt - just nothing more to do with it. I am keeping it with my 10k Cheetah and Miles card to use with music. I am waiting for a new QS 733 today maybe. http://macgurus.com/infopop/emoticons/icon_biggrin.gif

If your looking at a new/used macxhine and don't weant to spend $1400 after adding RAM, and other goodies on a QS 733. I have seen some great deals for around $800 - $1000 for the G4 450/500 Sawtooth with the 100MHz bus, AGP Graphic support, lots of nice add ons. The G3 and B&W G3 are nice machines but with the tech changing I see to many people with those G3's or even the PCI G4 versions wanting more.

I would get a 100MHz bus and AGP graphics port. The PCI G4 is the last series of machines with upgrades out. The Sawtooth versions are still waiting.

My 2 cents,
Good luck Randy

maXXed out
02-22-2002, 08:43 PM
Okay, folks... I just picked up my new drive (based on recommendation below - AND checking internal xfer rate specs at seagates website). It's a ST318406LW. I just hooked it up and am low-level formatting it as we speak with an older FWB toolkit (I can still set up for HFS+ after this, right?) . HOWEVER...a quick check of the defect list on FWB's SCSI configure reveal it to have a crazy high number of bad sectors. 866 to be exact. My FIRST cheetah had SIX (yes, 6!). My next one had two hundred something and turned out to be a real bum! So should I just take this thing BACK right now...? Or is it nothing to worry about??

------------------
Mac 7500
Sonnet 300MHz G3
Number Nine Imagine 128
640MB ram
Adaptec 2940UW
dual Sony GDM17SE1 monitors
Cheetah ST34501
Cheetah ST39204LW

TZ
02-23-2002, 11:35 AM
Maxxedout -

I would not trust using FWB on the latest Cheetah. Handy, but when I upgraded to 4.5 it was like $19 and worth the investment. You have to do a quick initialize to change it to hfs+. I'd use Drive Setup 2.0.7 (part of the 9.2.2 updater or 9.2.1 and probably on the 9.1 CD). OS X Disk Utility is probably the best driver utility at this point.

Do you have SoftRAID? Guess not. You can actually pick up some ATA PCI cards that include SoftRAID for very reasonable sum.

Depends on are those new defects or the factory defect list? Out of how many total? how many spares are there?

I would email Seagate support - after you have a driver that offers full support, I know in the past that even 4.0 didn't have full support for the newest 10k drives only last year at this time.

Gregory