First of all thank you for the fast and extensive answer but i have a few more:
1. Based on your experience from both scsi and sata what would be your recommidation for me ?
Depends on the type of data you looking to store.
Can you elaborate?
2. Same for software/hardware raid ?Never had to.
3. Have you done something that smells like NAS from the outside ? if so, what about disk/raid monitoring ?
However, consider the fact the Linux is remotely manageable by design, most NAS just use the RAID and Linux tools without changing anything.
-----Original Message-----
From: Gilboa Davara [mailto:[EMAIL PROTECTED]
Sent: Thursday, March 10, 2005 1:12 PM
To: Baruch Shpirer
Cc: linux-il@linux.org.il
Subject: Re: Linux NAS like Solution
See inline.
On Thu, 2005-03-10 at 11:07 +0200, Baruch Shpirer wrote:
Hotswap can be done both in SATA and SCSI
Both LSI and 3ware can do hotswap (and hotspare)
SATA would be the cheap and risky solution where as SCSI is more expensive and reliableIn my previous workplace we had both SCSI and SATA based storage (or actually streaming) solutions.
SCSI is indeed by far more reliable; SATA drive usually had a much higher failure rate. (Including a couple of very troubling two drive death that killed the array.)
3ware and LSI (megaraid) are both hardware solutions. *However* Tests I conducted seem to suggest that the Linux software RAID is actually faster then them both.
Most SATA raid solutions are Soft Silicon - Software based and use the system main cpu for the raid operations , there are some HW based like 3ware.
This shouldn't surprise anyone; a fast P4/Athlon/Opteron CPU is about 30 times faster then the i8/9xx RISC controller used in the SCSI/SATA raid controllers. On a fast dual Xeon/Opteron server won't even notice the 1-2% CPU time spent on RAID5 reconstruction.
***Oh***
Make sure you do hotspare. By doing RAID5 without a hotspare you're essentially asking for it. (And it'll come...)
Which seem on paper to be very good.The 3ware 7xxx and 8xxx are (very) reliable; though their write performance is less then impressive. (Read performance is OK.)
The 3ware 9xxx has a much better benchmarking skills, but I'd stay clear of it for now; We had *way* too many reliability issues with this card. (3ware is working actively to fix the damaged firmware and improve the driver so YMMV.)
Oh... 3ware's CLI tools are top notch; you'll be able to do most of the RAID's administration work using a simple bash script.
The LSI card behaves much like it's SCSI cousin (it even uses the same driver.) One problem: LSI is miles behind 3ware when it comes to management tools.
There's Adaptech and RaidCore; I've heard good things about them, but never had a chance to test them.
3ware 7xxx and 8xxx: Yes.
Next is can I trust the SATA Raid controller to do real reliable Raid 5 ? Cause going for SCSI comes to a price that I rather pay for NAS
3ware 9xxx: Can't really tell right now.
LSI: Yes.
Both 3ware and LSI.
Did anyone see or hear about a SATA Raid controller do hotswap in linux ?
At times 3ware had problems detecting a replaced drive. (A bit of fancy CLI work always fixed the problem.)
LSI works just fine.
Iam using gentoo and gentoo forum pretty much covered the software issues, I just need to know my HW fits.BTW, you can do hotspare and hotswap in software RAID just as well.
We had a SCSI software RAID solution (using a run-of-the-mill 29320 controller) and it worked just fine. (Besting the LSI MegaRAID solution by a nice margin.)
Again, give it a go; while YMMV it may save you a couple of $$$$.
Best regards
Baruch Shpirer
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-- Gilboa Davara <[EMAIL PROTECTED]> Nice Systems |
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Gilboa Davara <[EMAIL PROTECTED]>
Nice Systems
