I'm toying with the configuration of a new server I'm building and looking for input/feedback.

The server will be a 1U server with 3 drives. It will be a webserver.

The configuration that I'm leaning to is RAID 1 to mirror drive 1 to drive 2 and then using rsync to backup to drive 3 (also rsyncing offsite).

With this configuration I get some fault tolerence (if drive 1 or 2 goes belly up) but I still have drive 3 for daily backup.

Am I on the right track?

The next question is which is better:

Linux kernel (software) RAID
A Mylex or Adaptec RAID controller

Thanks,

Frank

Software RAID sucks.

Mylex rules adaptec:

http://acronymboy.com/ars/U160-Benchmarks-AMI.pdf
http://acronymboy.com/ars/e2000_vs_adaptec_3410S_detail_analysis.pdf
http://acronymboy.com/ars/E2000_vs_adaptec_3400S.pdf
http://acronymboy.com/ars/A352-vs-adaptec-3200s.pdf
http://acronymboy.com/ars/A170LP_vs_adaptec-2100S.pdf

Yes, the Mylex wipes the floor with the Adaptec, there is talk about how it might be biased in some way, but 2cpu's mod, Upaboveit agrees, that the Mylex really does perform much better:

http://forums.storagereview.net/viewtopic.php?t=2614

See also:

http://forums.storagereview.net/viewtopic.php?t=289
http://forums.storagereview.net/viewtopic.php?t=4373
http://forums.storagereview.net/viewtopic.php?t=4941

http://forums.2cpu.com/showthread.php?s=&threadid=17559
http://forums.2cpu.com/showthread.php?s=&threadid=17246

Secondly, go here:

http://storagereview.com/guide2000/ref/hdd/perf/raid/index.html

To learn about RAID. Run RAID 5.

Read about the XP issue here (very very long, from March 2002):

http://forums.storagereview.net/viewtopic.php?t=1758

http://acronymboy.com/ars/atto1.gif
http://acronymboy.com/ars/atto2.gif

Dont run WinXP as performance will suck. But since you are looking to go linux, you wont have to worry about that.

The advantages RAID 5 gives you is that one dirve can fail and it will still keep on going, without loss of data or downtime until you go swap in a new drive and tell it to restore (which it do without any down time).

Than rsync from that, off site in case something happens that makes all 3 fubar (power surge, flood, pebkac (happens to me more than powersurges do) etc).

Yea, I'm still going back and forth between RAID-5 and RAID-1.

RAID-5 gives me the best fault tolerence, but the least amount of storage.

I had already pretty much decided on the Mylex, but more input never hurts ;)

Frank

Actually, with RAID 5 if you have 3x70GB drives, you have 140GB of useable storage. If you have RAID 1 with 2x70, you only have 70GB of storage, and you are using the 3rd for backup. Even if you do 3x70GB of RAID 1, its only 70GB of storage. RAID 5 would be giving you more room. The forumal is:

(N-1) x Capacity

For RAID 1 it is:

1 x Capacity

Acronym BOY,

You are totally correct. Just before lunch brain cramp ;)

So should it be a Mylex 170 or 352?

Frank

Happens to me too before I get my morning coffee :D

The 170 is a single channel (only 15 drives) card. It uses a 32 bit PCI slot. A 32bit PCI slot (which runs at 33MHz) gives you 133MBps of maximum bandwidth.

If you want to make use of the 352's 64 bit PCI slot (which runs at 33MHz also, not 66MHz like some 64bit PCI), you will need a motherboard which has a 64 bit 33MHz PCI slot. A 64 bit slot gives you 266MBps of bandwidth. The 352 also gives you a second channel (15 devices per chanel lets you use 30 devices on this card).

A U160 channel gives you, yes you guessed it, 160 MBps to play with.

Of course all these numbers are just the calculated theoretical maximum throughput. Bus overhead, etc etc will prevent you from actually obtaining these numbers.

What harddrives are you looking to use? If you aren't looking for the fastest things and don't plan on hitting the 32bit PCI limitation, the 170 should be fine, but if you do want more throughput, the 352 would do better. Of course, if you don't have a mobo with a 64bit PCI slot, the decision is made for you already.

Now of course you need to somehow fit this all into a 2U case some how as well :cool:

You aren't looking to build a new server to colo phpBB, are you? (Don't mind me, I'm just curious and noticed your past few posts)

The MOBO is a SuperMicro P4DPR-6GM+.

2U? I want to cram this into a 1U :D.

I have other projects besided phpBB.com, just not as visible ;).

Frank

go with raid-5, it's still good for reads (web server mostly generates read io) and offers redundancy.

well, adaptec is still fine.. depends how much you want to spend since mylex is better and of course more expensive