RAID

[CptnObvious999]

Hello all,

I am looking into building a media center/torrent server/gaming machine and hooking it up to my 46" 1080p hdtv. I really would like to start with 3 WesternDigital 750GB Caviar's in a RAID 5 and then be able to put in another one in a couple months. I would like to duel boot as well so i can play some games on windows xp once in a while (booooo, hissss) but I do have an extra 80GB drive I can put in just for that.

So would you guys recommend a software raid or hardware raid? Is either one going to screw up the dual booting? Also how hard is it to setup raid and if its software raid how much of an overhead would that produce on my cpu?

I have heard that Fedora has great RAID support but has anyone heard otherwise?

Thanks in advance.

[Tsuroerusu]

I will preface the following, by saying that I hope to get a new computer within 1½ years or something like that, and I have considered RAID as well, to a much larger extent though (16 * 1 TB in RAID-6), so I have done a little research on the topic, but I don't have direct experiences with it.

Having said that ...

So would you guys recommend a software raid or hardware raid?

Definitely hardware RAID.

Is either one going to screw up the dual booting?

With proper hardware RAID (And not motherboard-based fake RAID) it presents a logical drive to the OS, the OS doesn't even see the actual drives directly, in your case with three 750 GB drives, the OS would see a giant 1500 GB drive.

Also how hard is it to setup raid and if its software raid how much of an overhead would that produce on my cpu?

Software RAID can put a fairly significant load on your CPU as far as I know, especially when re-building the array onto a new drive, if one of them commits seppuku. Hardware RAID is quite easy to set up, you attach the drives to the controller, go into the controller's BIOS and tell it what drives should belong to which type of array.

I have heard that Fedora has great RAID support but has anyone heard otherwise?

If you're referring to software RAID, I honestly don't know, I have never looked into it. If you mean hardware RAID, then I think it's a bit of a stretch to say Fedora has better support than others, as the OS doesn't really do anything fancy with a true hardware RAID.

I wouldn't bother installing both GNU/Linux and Windows onto a RAID array, it will only cause problems when Windows bitches about something, plus when dealing with expanding a RAID volume it's fairly critical to have some consistency.
I have looked into the expanding of RAID arrays as well, and it does indeed seem possible, but I have seen people report it taking up to twelve days on large arrays. It's much much simpler just creating the array you want at the outset and then going with that, rather than dealing with expansion. To be able to do it, it seems you need to use LVM, so that you can actually expand volumes. Because once a partition is created on a drive, you can't expand it without deleting it first and recreating it, thereby loosing all your data. With LVM, you create volumes, which you can then create "partitions" that are expandable, and then simply tell ext3 to eat the new space that has appeared. Generally, seems like a mess to me.

Also, I'd strongly recommend that you go with a RAID controller that has free software drivers. The reason is, that way it's gonna be built into the distribution by default, and makes installation so much simpler. Usually the producers of proprietary drivers package them only for certain versions of RHEL and SLES.

I've looked at different RAID manufacturers, and 3ware seems very good, their driver is free software, and they make good controllers. I will warn you though, hardware RAID is expensive, but you know, if storage is a priority then I personally think that throwing money into a RAID card is no different than throwing money into a high-end graphics card.

Here's one of 3ware's latest controllers: http://www.newegg.com/Product/Product.a ... 6816116064
Judging by the reviews, it seems extremely nice. Expensive though, although I have seen people throw at least 400 dollars into a processor, so in the end, what it all comes down to is what your priorities are in my opinion.

[CptnObvious999]

Thanks for all the info, I ended up going for a 3ware 9650SE-4LPML RAID controller because it was on sale. Works great with my 4 750gb wd harddrives. I definitely recommend this card, it was pretty easy to setup in the bios and the web interface in linux is pretty cool.