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View Full Version : Choosing a Card for new RAID on G4



jlswartz
03-13-2001, 12:27 PM
I'm trying to put together an order for the parts to "roll" my own RAID. I keep coming up with so many dumb questions that I thought maybe I'd pester this forum instead of using email.

My question today is:

Which card should I use? Here's the current configuration:
G-4 500
OEM SCSI card, supporting a DLT externally and a couple of internal drives
HVD SCSI card, supporting a Procom Reliant hardware Raid

Can anyone tell me how to tell which codename goes with this thing? Sawtooth, Yikes, etc.?

What I'd like to do is to add a new home-brewed RAID to this box.
I'm puzzled about whether to get the ATTO single or dual, and how to hook it up it it's dual. I'm also concerned that adding another SCSI card is going to cause ROM memory problems or similar on the machine. Maybe I should get a bluenote for the DLT, and put the new RAID on my existing LVD card? Will the internal drives slow it down? Will the Bluenote work with internal drives? Maybe I should replace the single channel with a dual, and plug both the dlt and the new Raid into that, or will that slow down the RAID to wait for the DLT? And, then what about the internal drives?

--confused as only a novice can be... I await your collective wisdom.
Thanks.

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John Swartz
Deskey Associates
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jorge
03-13-2001, 07:54 PM
I have no idea what the HVD SCSI card is so I will sit back on this one. The other Gurus will be by and help you out.

j

magician
03-13-2001, 11:55 PM
ok...first thing: what is this OEM SCSI card you have installed? Use Apple System Profiler to figure out its description. We need to know that.

we also need to know about your DLT, and your internal drives. Are they LVD? Or single-ended?

if you have an existing Proliant High-Voltage Differential SCSI card handling an external HVD array, and it is running reliably, leave it alone. We would not recommend attempting to add further devices to that bus. How old is it, btw?

this should get us started until Louie and K jump in with their guidance.

http://macgurus.com/infopop/emoticons/icon_biggrin.gif

jlswartz
03-14-2001, 10:20 AM
OK, thanks for the help.

First things first, thanks for pointing me to system profiler, never crossed my mind, duh. It tells me that the OEM SCSI card is an ATTO UL2D. It also says SCSI-2.

DLT:
According to Procom's website, it's "Fast-wide SCSI-2, Single-ended or Differential" the "or" in there is exactly the kind of thing that confuses me since I haven't got all the flavors down yet.

Internal drive:

This thing is a server which is presently under heavy load, so I can't open it up and look but my recollection, and profiler bears this out, is that there's one 18 GB Cheetah in there, hooked to the internal connector on the ATTO UL2D.

HVD and the Procom Reliant:
Yes, it works great, it's about two or three years old, if you don't mind the cost (OUCH) they're really wonderful boxes, but... they don't make them anymore. I have no intention of messing with it, or putting anything else on that bus. I admit that I didn't know better 6 months ago ( http://macgurus.com/infopop/emoticons/icon_redface.gif), but I do now... Fortunately I never tried it, I just *thought* about it...

I included the detail about the HVD Card in order to explain why I'm concerned that there are too many PCI cards in this machine.

It seems to me of course that if it's got 3 slots (or4) I ought to be able to use them all, but I've heard that's not how it works...

Thanks.



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John Swartz
Deskey Associates
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kaye
03-14-2001, 01:32 PM
John,

I'm a vintage Mac guy, so someone may jump all over me if I screw up, but let me answer some questions.

You have Sawtooth http://www.macgurus.com/beta/mbppcg4agp.html if you have AGP graphics. You have Yikes http://www.macgurus.com/beta/mbppcg4pci.html if you have PCI graphics.

You already have two PCI SCSI cards and, like you, I would be hesitant to add another. Sometimes they just don't like to coexist with one another. However, I have no experience with Yikes or Sawtooth. Someone who does, like magician or jorge, needs to comment. k

magician
03-15-2001, 03:26 AM
well, the first thing we need to confirm is that your existing ATTO card is single-ended, not LVD. Where did that card come from? If it shipped with the machine from Apple, then it will be LVD. If it came from some other source...it probably is single-ended. You may want to download the ATTO Tools utility from our FTP site, and see if it gives you any further information about that card. You may also want to download the latest firmware update for that card from the ATTO website, and see if you can flash the card. The utility will confirm the exact part number of your card.

the bottomline: it would be preferable to use an LVD array on an existing LVD card, integrating your existing drives and tape drive if they are also LVD. If they are single-ended, you may have no alternative but to install yet another SCSI board in that machine, and it remains to be seen whether it will work. Running a single-ended ATTO UL2D, and a Proliant HVD SCSI board, AND an ATTO UL3S LVD board, may not be viable.

jlswartz
03-15-2001, 12:13 PM
Thanks again for your help. I feel like I'm getting somewhere now...

So, the card has "LVD/SE" engraved in the end of it... is that contradictory? And it definitely did come from Apple. The ATTO tool says PCIUL2D. (I thought the D in UL3D stood for Dual, was I mistaken? or is the internal side one of the channels?)

Here's something interesting: It says the internal is differential, and the external (DLT) is single ended! So I guess that's the answer on the tape drive.

Would it make sense then to get the UL3D, put the tape drive and the internal Cheetah on one channel (the way the PCIUL2D is now) and the new RAID on the other? (and then repurpose the PCIUL2D?)

Or, would that prevent the RAID channel from performing as it should?

Thanks.

Another thought, can anyone point me to a source for info about why this problem with too many PCI cards occurs in the first place? Maybe a TIL article?



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John Swartz
Deskey Associates
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magician
03-15-2001, 01:47 PM
it sounds to me like you have an Apple version of an ATTO card, and if I am not mistaken, it does have two buses, but only one internal and one external connector, each to a different bus.

now. If your DLT is working ok on that card, I am inclined to leave it alone. That leaves the internal Cheetah. Is this your boot drive? Or just a second drive? Is it single-ended? Or LVD? How is it terminated?

since you have an LVD card, we may be able to get you out of this without building an external enclosure. It all depends on how much storage you require. Do you know? Considering that 73GB Cheetahs are available now, and a pair of them installed internally will give you 144GB of striped RAID 0 storage, that may prove to be adequate for your needs. All you will require is a pair of drives, a license for SoftRAID, four screws per drive, and perhaps a replacement cable with inline terminator.

you mention a "pair of drives" in your first post, but then just a single 18GB Cheetah, later. How many drives are inside the machine? Just the Cheetah? Or do you also have an IDE drive? Or more than one SCSI? This will determine whether we can stick with internal drives, which will be much more economical, and easier, considering the hardware you are already running. As I see it, it would be better to disrupt your current arrangement of boards as little as possible. If it is working, we should leave it alone as much as we can. Adding a couple of drives to an existing LVD card shouldn't be much trouble, assuming you have room inside.

http://macgurus.com/infopop/emoticons/icon_biggrin.gif

jlswartz
03-15-2001, 04:55 PM
I'm glad we're having this discussion, lots of food for thought.

The confusion over the internal drive was caused by my forgetting that what I see as two ~9 GB volumes is really two partitions on one drive, so, yes, just one internal drive. I'm afraid I don't know how to answer the termination question, it's in the factory configuration. According to Seagate's web site it is an:
ST-318203LW Ultra2 SCSI Wide (Cheetah 18LP, LVD)

As far as how much storage we need, the answer of course is "as much as we can get..." but, a while back we bought 5 18GB IBM Ultrastar drives which he had intended to use for this purpose. I think mounting them internally could be a problem. Then I'd still need the Cheetah in there to boot from...

I've just called Procom, and they tell me that the DLT is "plain old narrow scsi". They say it'll work on any basic SCSI card. Further, we had it connected to the on board scsi of a beige G3 for over a year, where it worked OK. (Performance has been a little better with the G4 but I don't know if that's the scsi or the processor.) I really don't have any concerns about moving the DLT around.

My options as I see them:

1. Put the DLT on a bluenote and put the new Raid on the existing ATTO. Hope that a bluenote is not enough to over burden the pci bus/es.

2. Find some other use for my UltraStars, and buy two new 73 GB Cheetahs, and install them internally. I imagine the existing Cheetah won't interfere with them? (since they'd be on the same chain...) If I go internal, it'll be harder to repurpose later, but it'll cost less to make up for it...

3. Get a dual channel ATTO and replace this single with it. Connect the DLT to one channel, and the new RAID to the other externally, and then the internal Cheetah to the first channel internally. Repurpose the existing ATTO card.

4. Buy another single channel ATTO, put it in the last remaining PCI slot, reboot, and hope it comes up...

Am I missing any?

Thanks again.

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John Swartz
Deskey Associates
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MacMikester
03-18-2001, 06:52 PM
Hey jl,
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>My options as I see them:

1. Put the DLT on a bluenote and put the new Raid on the existing ATTO. Hope that a bluenote is not enough to over burden the pci bus/es.

2. Find some other use for my UltraStars, and buy two new 73 GB Cheetahs, and install them internally. I imagine the existing Cheetah won't interfere with them? (since they'd be on the same chain...) If I go internal, it'll be harder to repurpose later, but it'll cost less to make up for it...

3. Get a dual channel ATTO and replace this single with it. Connect the DLT to one channel, and the new RAID to the other externally, and then the internal Cheetah to the first channel internally. Repurpose the existing ATTO card.

4. Buy another single channel ATTO, put it in the last remaining PCI slot, reboot, and hope it comes up... <HR></BLOCKQUOTE>

1) This will work just fine and will not overpower your PCI bus, but may not be necessary or optimal. See following.

2) This is probably part of your solution; if you are really prepared to get rid of the HVD card and RAID box and replace the functionality with a new LVD 146GB RAID.

3) Your ATTO card is dual channel but it is a weird version that Apple came up with, with the external limb of one channel and the internal limb of one channel hacked off so you have separate internal and external busses. You could run your DLT in SE mode on the external channel without affecting an LVD setup on the internal channel (*this would require the card to provide SE termination to the external bus and LVD termination to the internal bus*). If you get a new ATTO UL3D, and hook up the single LVD Cheetah you have now on the internal leg of one channel with the DLT on the external leg of that channel, the Cheetah will be forced into SE mode, your internal LVD cable is the wrong impedence, you will need a separate SE terminator (because an LVD drive has no termination) and all manner of SCSI complexities may fly up your nose. The RAID on its own channel would be fine.

4) This will work fine and will not overpower your PCI bus, but may not be necessary or optimal. See following.

Assuming you are prepared to replace the HVD RAID with a new internal LVD RAID, your best option as I see it:
Buy a new retail ATTO UL3D and dual 73 GB Cheetahs, keep your Apple ATTO UL2D. Run the Cheetahs bus duplexed across the two internal channels, one each, of the UL3D card (much better throughput than both on one channel). Run your single internal Cheetah boot drive and your external DLT on the separate channels of the UL2D.

You can mount three drives in your box, but if you want future RAID expansion with portability, you could run the Cheetah RAID in an external enclosure bus duplexed across the two external connectors of the UL3D. Your new RAID would blow the doors off your current setup.

PS: There's a somewhat recent thread somewhere on this site discussing some peculiarites regarding running a G4 with OEM and retail ATTO cards onboard. If you search the SCSI , RAID or New World Mac forums, it should turn up. I think the issues were resolved, but I can't recall the details.

Regards

[This message has been edited by MacMikester (edited 18 March 2001).]

magician
03-19-2001, 03:27 AM
I think MM's advice is good.

I will say this, though. There is no real need to mess around significantly with what you already have.

You have a dual-channel card, and one channel is handling your DLT just fine, and your current Cheetah just fine. Your current Cheetah is an LVD Cheetah. You have room for two more, assuming there are no IDE drives in this machine.

All you really need to do is replace your existing LVD ribbon cable, unless it already has enough vacant connectors for two more drives. If it does, just install another pair of Cheetahs, and stripe them using SoftRAID 2.2.2. Test your performance, and post here. If it sucks, we'll tell you, and you can then purchase an ATTO UL3D or UL3S. If it's not that bad, well, you can then skip a $350-$500 purchase of an ATTO card. The Gods of Capitalism can spank me behind the woodshed later, if they can catch me.

http://macgurus.com/infopop/emoticons/icon_smile.gif

this leaves your Proliant untouched, for now. This also leaves your DLT untouched, for now. And you are booting off the same drive, and adding a pair of 10k Cheetahs. If 144GB RAID 0 isn't enough room for you, we will begin shipping 181GB 10k Cheetahs later this week.

http://macgurus.com/infopop/emoticons/icon_biggrin.gif

They will run a whopping $2k each, at least at the outset, but there is no cheaper way to build a 362GB RAID 0.

I'll be overhauling the Seagate page later this morning or tomorrow, depending on how much longer I have to surf on the forums.

http://macgurus.com/infopop/emoticons/icon_biggrin.gif

jlswartz
03-19-2001, 10:10 AM
I just wanted to thank you all for your help and suggestions. Now I'll mull it all over and figure out what to do...



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John Swartz
Deskey Associates
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