On Sun, Nov 24, 2002 at 12:38:56PM -0500, Scott wrote: > After some talks with the person who handles the books she has given me > the authority to bail on these Netfinity boxes and get something more > supported by Debian. My question is: with IDE drives as fast as they are > now does it really pay to go SCSI? Are there any benefits besides RAID? > I understand fault tolerance, but how about performance?
I have used SCSI and IDE in many levels of the game. I've also used filers (Netapp). I currently work with an ISP that has mostly IDE on the servers doing miscellaneous stuff, all SCSI RAID5 on the servers such as database, NFS and network monitoring. I just like being able to pull a drive hot and replace it nice and easy in the servers that are most critical to me. There's quite little point in having IDE for my work on the most mission critical servers. We also have a habit of netbooting many of our machines. POP/SMTP/HTTP/HTTPS/DNS are done via netboot. This reduces our reliance on drives in tons of systems. I would be happy to know if there are controllers and setups that allow hotswappable IDE RAID5 - I'd be very interested if there were (please feel free to let me know on or off list). At home, where we have a completely overbuilt network (geek!) I have a server with IDE software RAID1 (dual 40G) and a SCSI RAID5 array that is external and on a module installed basis so I can move/add/remove drives at will - without losing my uptime on the main machine. My SCSI array is currently 54G, but will expand again in the spring when I make some other upgrades and free up more like drives. I also like to add and remove my SCSI CD-ROMs as well, just cause I have several laying around. I've seen (figuring off the top of my head) a 3:1 IDE/SCSI failure rate across all drives/servers/systems. I'm not recalling that many failures all told. I can actually only recall two SCSI failure, a 2G WD and a 18G IBM. I've had multiple Fujitu IDE, WD IDE failures, sometimes with the replacement drive failing in the same machine (Grrr) Overall, this would be my recommendation (IMHO - YMMV) IF you can get a combination of good IDE drives with good IDE controllers that don't peg your CPU usage and money is an issue, go with IDE. Never put two RAID1 IDE drives on the same channel (primary or secondary). Put one on each for safety. For storing mp3's at home or files locally, IDE is generally well suited and will save you a lot. If you've got more money and want to see a (actual, not spec) better MTBF, go with SCSI. Take the time to learn how SCSI works, terminations, etc. Research block sizes on RAID arrays. Experiment to get the best speeds. Use multiple controllers if you want. Have proper cooling. I think SCSI edges out IDE for reliability and I think the extra cost is worth it. And if your data is super mission critical, just buy a filer instead and use snapshots. If, as I reread your question, you just want to know "Is SCSI worth it for speed?" - no, probably not, you can do well with an intelligently configured IDE system. $.02, FWIW, John -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
