Re: [OT] SATA vs. SCSI
On Thursday 27 October 2005 06:33 pm, Gene Heskett wrote:
> On Thursday 27 October 2005 18:56, Roberto C. Sanchez wrote:
> >I will hopefully soon be building a server to donate to my church to
> >replace a used one that I donated earlier this year. My question is
> >this: Is SATA or SCSI preferrable?
> >
> >I am shooting for top notch reliability. I understand that components
> >will occasionally fail. However, I have always understood that SCSI was
> >preferable to ATA. Now that SATA is in the mix, I am not sure if that
> >is still true. I have not kept up with the latest and greatest in terms
> >of technology developments in that area.
>
> Speaking as the retired CE of a tv station where it was always said that
> scsi was best, I have problems with that statement. Our first foray into
> using a scsi based commercial server resulted in its getting converted to
> ata disks fairly rapidly as the scsi raid lost a drive at 2 week
> intervals. A single big atapi/eide drive turned out to be faster, and a
> heck of a lot more reliable.
>
> Ditto here at home, I gave up on scsi tape drives about 18 months ago and
> bought a 200GB atapi/eide drive & setup amanda's virtual tapes on it. It
> has so far, been about 100x more dependable than the scsi tape ever was.
>
> Now we've gotten into the video server scene, again with the recommended
> terrabyte raid, scsi3-320 or some such based with a 1394B (800
> megabits/second=100 megabytes) interface to the servers, and again scsi is
> being a problem child with an occasional stutter while playing and always
> a missed first word as it starts. Put the same program file on a single
> internal big atapi/eide drive and the performance is 100% reading while
> writing so we put in 2 drives per server. Now our main concern is that we
> don't seem to be able to find an rsync workalike that does both branches
> of the apple filesystem so that we can fabricate a darned near realtime,
> live, online, redundant backup in case one server chassis should upchuck
> in the middle of a program playback.
>
> If anyone has a clue how we can simulate an rsync run between 2 dual g5
> servers at 5 minute intervals, we're all ears.
try unison:
http://www.cis.upenn.edu/~bcpierce/unison/faq.html
use it to sync a semi large personal music repo and seems to work fine. put it
in cron or something to do it every 5 minutes.
if you want realtime replication, i'd suggest drbd
http://www.drbd.org/
it's "RAID over TCP/IP" and has been working great for me for over a year now.
it probably puts a slight drag on performance (depending how you configure
it) but for us, we can take the performance hit in exchange for the high
availability it offers.
don't know if it works on OSX etc. but then this isn't really an OSX mailing
list.
>
> >Tha machine will be acting as a terminal server and also housing all the
> >user home directories and probably a few other services.
> >
> >I am wondering what the rest of the world, at least as far as those that
> >read this list, think.
> >
> >-Roberto
>
> IDE raid, at least raid5. Why pay $100 or more per drive for the
> priviledge of poorer drive lifetimes and performance by using scsi.
> Its not worth the headaches when it absolutely has to work right the
> first time everytime.
> --
> Cheers, Gene
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> 99.35% setiathome rank, not too shabby for a WV hillbilly
> Yahoo.com and AOL/TW attorneys please note, additions to the above
> message by Gene Heskett are:
> Copyright 2005 by Maurice Eugene Heskett, all rights reserved.
hope it helps.
anoop.
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