On 27 Jun 2002, Joon Guillen wrote: > We are planning to buy a couple of servers to be used primarily as www + > database servers [ie. a content management system]. We now need a > (hardware) RAID system for these. Unfortunately, SCSI RAID systems are > a bit steep on price, and I was thinking of using IDE RAID instead (we > need only 2 disks per server anyway). I don't know much about RAID yet, > so my question is, will the IDE RAID system work well with Linux?
So far only the following brands of IDE raid are available locally: Promise (PDC) HighPoint (HPT) Of which both implement firmware-RAID, not really Hardware RAID. firmware-RAID implementation is supported by the kernel for only RAID-0. If you want to go to higher RAID levels, you can't. See http://people.redhat.com/arjanv/pdcraid/ataraidhowto.html Alternatively you can enable raid 1-5 by using the binary only driver provided by promise, but i'd rather not. Say no to closed source binaries like this. Besides they don't keep up with the kernel versions, and you'll be stuck with an old (and probably insecure kernel). If you buy a promise or have a board with HPT included, you can just configure the drives as JBOD (just a bunch of drives), and implement software raid on them. Coming from the linux kernel ide developers, they say that firmware raid is no faster than linux software raid, so you might as well just dump the firmware-raid feature and go with a more supported approach (linux s/w raid). An alternative is to use the 3ware escalade raid controller. Both Jijo and me have been using them for quite a while with no showstopper problems so far. The driver for this brand is open source and regularly fed into the mainline kernel. It even comes with a web based administration utility. The only problem with 3ware is that there is no local distributor, and no local support. I got mine from the US \8( 3Ware is true hardware raid. It has a special RAID chip that does the actual mirroring or parity, and offloads the processor from what would have been a very cpu intensive task given the nature of IDE devices and the functionality of RAID systems. > Does the kernel support it? Software raid yes. Promise PDC, and Highpoint HPT, partially. > Or, is RAID completely transparent from Linux? When properly setup yes. > Additionaly, would you recommend IDE RAID at all, provided our current > server's purposed function, or would it really be necessary to get SCSI > instead? As i said before, existing IDE raid systems give the same value and performance compared to more expensive scsi alternatives, so there is really no reason to go with SCSI RAID anymore. _ Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph To leave: send "unsubscribe" in the body to [EMAIL PROTECTED] To subscribe to the Linux Newbies' List: send "subscribe" in the body to [EMAIL PROTECTED]
