We have just installed RedHat 7.1 on an AMDK6233Mhz machine. We plan to use it as a backup storage for our data. We plan to use RAID controllers for IDE.

Will IDE RAID controllers work under linux?
Is there a documentations on how to implement it? and also what controllers are compatible with it.

SuSE has support for the 3Ware IDE RAID controllers. AFAIK the Rromise RAID cards will not work under Linux, but their RAID Tower will. It's a tower of either 4 or 8 IDE bays which runs off a SCSI interface.

The 2.4.x kernels will do software RAID nicely, and the 2.2.x kernels will need a patch.

thank you for replying,

i see..we plan to get the Promise RAID card. I'll try to check if the RAID card by 3ware is available here in the Philippines. Also, what do you mean by "The 2.4.x kernels will do software RAID nicely, and the 2.2.x kernels will need a patch."?

does that mean that we do not need to get the RAID card in order to make it work under linux? We have red hat linux 7.1
which i think is a 2.4.x kernel, does that mean we can basically install 2 drives and configure it as to work as raid?

we are just after raid 1 which is mirroring since we intend to put up a server there we can store backup data files.

Software RAID will do the same job as the basic Promise RAID cards which don't do much more than manage the stripe sets. As I mentioned before, I don't know if the Promise RAID cards will work in Linux.

If you need real performance you'll want to look at a RAID solution that incorportates an onboard RAID controller with some real power and memory. This takes some of the load off the CPU and I/O when doing a hot-swap/rebuild of an array member.

I am currently runnning softwarre RAID-5 on some of my servers and one workstation and am very happy with it. I use both ext2fs and reiserfs on them.

If you have the budget and you need the speed, look at the 3Ware Esclade 6800 card or the Promise UltraTrak/100 (SCSI-to-ATA) box.

If you can get some good SCSI drives and a u160 SCSI controller, the software RAID can be nice.

If you're poor like me, get a one or more Promise Ultra/66 or 100 controllers and throw some ATA drives at it. Don't slave up any drive in your array - one driver per controller interface.

Mcleodnine,

unfortunately, we don't have the budget for scsi drives. That is why we were looking at IDE drives since they are cheaper.

i'll try to study on how to implement software RAID. can you suggest any documents that i can start off with? I will try to look for it at linux how tos.

also, can i ask you why did you use RAID-5 and not RAID-1? Is it because if you use 2 10Gig drives in RAID-1 you can only use 10G and if it is RAID-5 you can use 20Gig? Am i correct at this?

From what i understand if RAID-1, say, if you have 2 drives imirrored and if one of the drives fails, the other still has a backup of the data. In RAID-5 what happens if in case a drive fails? Will the data be lost?

thank you for answering my questions and you have been really helpful.

jay

For RAID 4 or 5 (well, let's just ignore RAID4 and treat it like the red-headed stepchild it really is) You need at least 3 drives. My 3 10GB platters on my desktop RAID5 array gives me 20GB. I could get 10 GB in RAID1 and have a hot spare, or get 30GB and use RAID0 (scary).

Check out linuxdoc.org and bookmark it. It's a great resource.

The 3Ware cards support linux in general. Here at the office we have a server with a 3-ware IDE-RAID controller running Slackware. It works really well. Adeptec also makes a few hardware IDE-RAID solutions but I think the 3ware is probably the best for its cost.

The biggest thing here is to avoid software RAID controllers, as they require drivers and CPU time to perform the RAID functions. Hardware RAID controllers do everything seamlessly in the background and don't use any of your CPU power.

John

jtshaw: I'm glad to finally hear about someone actually using the 3Ware cards. I was looking into one for myself but it was going to cost about CDN$500 to get one shipped here. It seemed like a lot of money for something I have only seen in a press release. Are you using the 6800 or he 7000?

We are using the 6800 currently but there was some talk about a another machine using the 7000. It works really well and has a nice web interface for checking on the array's and things like that. It is even setup to send a text message to a few of our cell phones if the array goes bad so we can check on it.

I checked out 3Ware's website and checked out the Escalade 6000 series and 7000 series controllers.

Just wondering, will the controllers work on old machines? The machine that we plan to use is an old HP Vectra Series 4 which has a Pentium 166Mhz CPU. Also, the machine can only detect drives up to 8GB. And we plan to use 30 maybe 40 Gb of hard drive. Will the size be limited to 8Gb only or just like SCSI, will it detect the 30Gb drive?

Hi all
I am the owner of an Promise TX2000. I run red hat 7.3 with 2 disks in a raid 0. Currently I am very unhappy with my Promise TX2000. Performance is not very good and I think is i even the controller or the driver from promise that causes my linux box to crash.

Currently i am thinking of buying a 3ware ide ata raid (properly the 3w7500-4). But I want to hear some experiences first.

- Are there native kernel support in linux ?
- Is it easy to install (insert cd, and install :-)?
- How is performance?

Hope anyone can provide some positive (or negative input).

Best regards Henrik