Raid

[bigbeark]

I have an Abit KT7A-RAID that I use with a 29160 SCSI card.

I have never even tried using the Highpoint RAID feature of this board (I know its IDE only). Would a 4-disk array of small IDE drives outperform ths SCSI? Anyone know if Ubuntu supports the Highpoint?

I can also get SCSI raid cards cheaply enough, which I could use on any board.

I have such a card but am uncertain as to how it is to be cabled. If I just use the RAID card and attach a SCSI drive to it, nothing happens. I assume the SCSI adapter card must be connected to the SCSI RAID card and the RAID card connected to the Drives. Is that how it works?

Again, would I expect superior read speeds? If this were a desktop, not a server. would I notice any difference at all?

I see all kinds of people going on about RAID but wondered if it was just one of those "bragging rights" situations when used in a stand-alone machine.

[Scenic]

Re: Raid

the Highpoint HPT370 is a software RAID.
not sure about linux, but it works well with XP and the like (at least for a software RAID..)
if you can get a couple reasonably fast (= fairly new) IDE drives for it, it should outperform the SCSI setup easily..

as for wiring the SCSI card up.. it's not just plug & play unfortunately... drive IDs have to be set right, terminators have to be put into place, ... all that kinda stuff..
i'm not familiar with that adaptec (?) 29160 card though.. so i cant really help here.

all i ever had was the ancient adaptec AHA-2940UW with a bunch of 2GB and 4GB drives.. and that setup was actually a bit slower than a single (equally old) 6GB IDE drive..

[Uranium-235]

Re: Raid

all depends on how you set it up.

scsi is usually faster per-drive, but you don't need the 29160 card to get raid, just a raid card

if your drives are SCA (single, long 80 contact connector) it usually sets the drives automatically if you're using a drive cage

but if you're using regular high density 68-wire cable, you do have to set the jumpers manually on the drive

also make sure you terminate it properly. ether have a terminator on the end of the cable, or put a drive on the end of the cable and set it as the terminator with jumpers

if you have trouble getting all the drives working, try connecting just one at a time, make sure you set the jumpers right. some drives have a small jumper array on the board, seperate from the back jumper connectors

the jumpers are set in binary

there is a jumper for 1, 2, 4, 8

so, if you want your ID to be 3, put the jumper on 1 and 2

[Per Hansson]

Re: Raid

4 IDE drives on a 2 port IDE controller?
No way, the slave drive can't communicate when the master is communicating and vice versa
Performance will suck vs the SCSI setup
Plus it will use allot more CPU time, which for such an old system makes allot of difference

[Mad_Professor]

Re: Raid

You will need dmraid on ubuntu, it's not installed by default. But goodluck trying to get it to work with the highpoint. You would be better off getting the source drivers from highpoint and compile it. But the last time I tried for my 1740 card, it broke the kernel pretty bad and scrambled my drives. A good zero-ing out the drives fixed them.

SCSI drives will out perform PATA drives if the drive speeds are more then 7200RPM and in a lun or raid.

Is the SCSI card a PCI or PCI-X or PCI-E?

If it's PCI, forget it; it's not worth the raid, since the PCI Bus is a bottleneck. You would need a good northbridge, decent drivers and good circiut design in order to achieve 80% of theoretical 125MB/s, and it's a shared bus, so more cards or other integrated devices *ie IDE/NIC will take quite bit of bandwidth.

PCI-X 64bit is a better choice, it has more bandwidth which means bigger data transactions but PCI-E and SATA are overtaking SCSI platforms, due to being cheaper and easier to manage.

IDE raid is no good unless you have dedicated ide channels to each drive as in Primary and Secondary on the board follow by PCI IDE plug-in using the Primary and secondary channels of that, then set one drive for each ide cable to master. Again if it's PCI, it's sharing the bus, so performance is negligible at best.

If you want to do this for shits and giggles then go ahead. I would recommend linux raid *mdadm,* since that what highpoint does anyways. It replaces the module for their chipset and then interface with mdadm, the only upside is their easy web based configuration page for their controllers.
Even if you don't, mdadm is just as good as hardware raid, that is if you have a decent processor and good PCI-X or PCI-E storage controller to handle it.

mdadm is good for basic configuration like span, 0, 1, 0+1, 4,5,6. But you can make it do complicated raid setups like 50 or 51.

I'm gonna brag now...

I have 6x 1TB Samsung drives in mdadm raid 5 using intel *deep down it really is a LSI design using a intel firmware* pci-e two port mini-sas 8087 to 4x sata fan out cables. I played with it before settling on raid 5. I had it in mdadm raid 0 and max out the ports on the card being 300MB/s each port, I achieved 585MB/s read and write doing a dd test. In Raid 5 it hangs around 290MB/s.
None the less it was still impressive. I just wonder what I could do with the 4 port version.

HTH
~MP

[PCBONEZ]

Re: Raid

Just some thoughts.

PCI-X cards that work on 5v will work in standard PCI slots as long as there is clearance for the extended length of the card in front of the slot. [Is best to put some electric tape on the exposed slot fingers.] - It will still operate in 32-bit/33MHz mode so that part is not the advantage. The advantage is PCI-X RAID cards are usually FAR better cards w/hardware RAID [and they are getting cheap].

Standard PCI cards also work in 5v PCI-X slots. The Bus it's in will kick back to 32-bit/33MHz -but- mobos with PCI-X slots typically have multiple PCI Busses. The card might not be running any faster than on a conventional mobo but [if you are paying attention to the boards tech-specs for the slots] it can be on it's very own dedicated Bus and not sharing it's bandwidth with other cards or chips.

PCI-X RAID cards are far cheaper than comparable PCI-E RAID cards.
In some cases 100's of dollars cheaper.
[That means spending more for a PCI-X mobo and less on the card the can still end up -way- less expensive over all.]

I don't do SCSI so I don't know model numbers for those.
- To go into a std PCI slot the 3Ware IDE/SATA cards to look at are the 7000 thru 9500 series.
Those all work in 5v slots. [And at least some -also- work in 3.3v slots.]
The 9550 and above are 3.3v only.

If you are thrifty and patient [and a shopahaulic] you can set yourself up with a mobo+cpu+8Port card [all PXI-X] for under $100.
-
It's easier if your chassis can support an E-ATX mobo but their are dozens of ATX options with PCI-X if you look around.
-
I've even found uATX boards with PCI-X slots that use Pentium-M CPUs for low power consumption. Sounds wimpy but it's PLENTY enough CPU for home or small office file server/NAS.
.

[Wizard]

Re: Raid

PCBONEZ is correct. I woke up and got smarter, played the game and figured out what can do with less for getting older "high end" stuff.

Cheers, Wizard

[Uranium-235]

Re: Raid

another note

all PCI-X operates at 66mhz, 100mhz, and 133mhz. some cards do not like speeds they were not designed for, some do

scsi is ok with a good enough hardware-based raid pci-x or pci-express card

most hardware pci-express cards are x8

[ratdude747]

Re: Raid

they even make hardware raid cards for regular pci... I found a 3ware 2 port ATA133 one for pci for $12 on ebay,,,

[PCBONEZ]

Re: Raid

another note

all PCI-X operates at 66mhz, 100mhz, and 133mhz. some cards do not like speeds they were not designed for, some do

scsi is ok with a good enough hardware-based raid pci-x or pci-express card

most hardware pci-express cards are x8

Stop reading Wikipedia, it's wrong...
PCI-X operates at 33mhz as well.
- It's required by all three PCI-X specifications.

This isn't complete or 100% accurate either but it's more accurate than Wikipedia.
https://cdn.badcaps-static.com/pdfs/...df6261ed03.pdf

There were early PCI-X boards and cards that did not do 100 or 133 MHz.
Even after that some mobos are limited to 66 or 100 MHz due bus load limits on the particular board.
[I have one board with two slots on one of the PCI-X buses. It is 133MHz max if you have one slot filled but limited to 100 MHz if you fill both slots.]
.

[Uranium-235]

Re: Raid

not ONE time did I read from wikipedia writing that article

I had a LSI scsi controller I tried to put in a Poweredge 1800 and the bios told me the card could not operate at 100. thats where I got this information

[PCBONEZ]

Re: Raid

Probably an old card from before PCI-X got to 100MHz.

There should have been a BIOS setting or jumper to slow down the bus on the mobo to make the card work.
- Either that or one or the other was not compliant with the standards.
Poweredge are a bit on the proprietary side.
I wouldn't be surprised at all if they don't comply with industry standards.

Newer [compliant] boards typically kick the bus speed down to the slowest installed card automatically.
.

SCSI card should have worked in slot 1 on that board.
It's was 64-bit, 66-MHz, 3.3v slot. [Only looks like a 32-bit 5v slot. - Key is on the other end though.]
.

[TBoneit]

Re: Raid

I will put it this way I'm using a IBM workstation with a 10,000 RPM SCSI drive, The drive is faster than a regular IDE drive.

OTOH it takes longer for the startup since the SCSI card has to initialize, Locate the drive ID and then start the boot process. It is faster when running however and many of these SCSI drives last much longer then IDE or SATA drives.

[PCBONEZ]

Re: Raid

Any 10,000 RPM drive will be faster than a slower drive.
Doesn't matter what kind.
.
The bottleneck on hard drives is the head-disk transfer rate which doesn't change much at all between SCSI, SATA, or IDE.
... But it does change much with RPM.
.