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SATA or SCSI - need advice

Hi, I need some advice from little experienced experts.
I'm about to buy a server, which would be application server for about 20 xterminals.
Nothing sophisticated. No development. Web browsing email reading possibly document writing.
Runnig under linux.

Now, what would You suggest as a storage?
I was thinking about 3ware or ich7 (NCQ) + 2 150G SATA Raptors in mirror (either software or hardware from 3ware)
As opposite I could use smaller SCSI disks with linux software mirror.

What You think? Maybe some links to some comparation tests?

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rindi

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rindi

Forgot the link to areca:

http://www.areca.com.tw/index/html/index.htm

ravenpl

ASKER

Thanks for the Areca link - I wasn't aware of such controller, I thought that the world starts and ends at 3ware ;)

Why You so strongly against software mirror? It looks good, no resources usage, read dispercing. If the driver and controller and drive would support NCQ, should work well.

rindi

It still uses the PC's CPU. Of course with mere mirroring (if you don't need a higher level of raid like raid5 etc) that isn't a big deal. Software raid controllers are often not well supported in linux and need some tweaking, you often have to use software raid inside linux itself to get them going. For hardware raid it is more likely you have direct linux support, also because the cards are more expensive they have to supply better support.

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Gary Case

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rindi

I don't think the ICH7 has any proper linux support.

Gary Case

... I don't know the answer to that ==> but the Fedora Core installation guide clearly indicates that if motherboard-supported RAID is configured, it will use it just fine. Haven't tried it with Linux, so I don't know. Worth a try I'd think.

ravenpl

ASKER

ich7 is supported by the ahci driver under new linux kernels. That's OK.
But garycase: so far I know linux sees physical drives instead of array configured with ich7's bios...
There is driver provided by intel, but people say to use linux soft raid instead.

Gary Case

The kernel may only be using the ich7 in "IDE" mode - in which case the array won't be seen. The only reason I can think of to use Linux soft-RAID instead of the ich7 is if you want to use a RAID mode not supported by the ich7 -- unless there's some conflict with the Intel driver.

But either should work fine -- the disadvantage of the software approach is primarily the CPU overhead; and for a mirrored array that won't be too bad. I'd suggest trying it with the ich7 driver first, however => the CPU overhead for the Intel driver is typically < 1%

scrathcyboy

I would use a mirror for sure, either RAID 1 or RAID 10 (if you want 4 drives) -- sure a mirror is somewhat slower, but with modern fast drives, you wont notice much difference, and with a mirror, you will never lose your data. People are always losing RAID 0 and 5 arrays, evidenced by number of problems coming in to EE.

ravenpl

ASKER

Thank You.

rindi

your welcome

Gary Case

You're most welcome.