The last example comes from reader Madal:
I first built a Windows XP box using the behemoth Lian-Li V2100 case (12 x internal 3.5 drives. Frankly, I have no idea why I bought it at the time! I thought it looked cool and aptly named it "The Monolith" for the purpose of archiving my 2000+ CD collection as 320 Kbps MP3s.
I bought a 320 GB WD for the job, and threw in whatever other drives I had laying about. About 4 months later, that brand new HD died, and I had not backed it up, thinking "well, it's a new drive....." Famous last words. Four months of ripping, and 120 gigs lost. Never again. Nor will I ever buy another WD drive.
Then I set about my quest. I bought 400GB Seagates when they were sale priced @ $110 or less from Fry's, and acquired enough drives, with spare parts, to build this:
|CPU||AMD Athlon 64 3000+|
|Motherboard||Asus A8V-Deluxe||IDE x3 + SATA x4 onboard|
|Power Supply||Thermaltake 750W|
|Ethernet||10/100 (included in motherboard)||(included in motherboard)|
|Drive Controllers||Promise Tech||SATA x4|
|Silicon Image (SIIG) IDE PCI Card||IDE x2|
|Hard Drives||- Seagate 400GB Barracuda 7200.9 (IDE)
- Seagate 400GB Barracuda 7200.10 (SATA)
|- 2x IDE, 6x SATA configured in RAID 5
|- Seagate 300GB Baracuda 7200.9 (IDE)||- 2x IDE in RAID 1 for OS|
Madal's NAS Parts
I tried a number of OSes, including FC6 and Suse 10.1, but I could not make them work. I think the problem with that GRUB would look for the MBR on a drive other than the one the BIOS designated as the 1st HD, but I never could figure it out. I did get FC6 to format my RAID 5 array in ext3 until I could find an OS to make it all work. The only OS that let this monster fly was Debian, the "Swiss Army Knife" of Linux.
Inside Madal's "Monolith"
I had thought about FreeNAS, but they were having problems with geom vinum volume manager and RAID 5 at that time (I think these problems have since been ironed out).
Note that I have no hardware RAID controllers operating. It's all done through the software magic of mdadm. For whatever reason, I was never able to get GRUB to boot the RAID1 array, I had to use LILO.
I also had problems with a Promise Tech IDE card (PDC 20268 chipset). The kernel constantly reported latency problems. But I have had no problems since switching to a Silicon Image (SIIG) card. Also, the hard drives will run very hot (up to 50C), so I have to leave the side cover off the box.
I ran iozone on "Monolith" and plotted the results along with the Synology DS508 data taken from the NAS Charts. Keep in mind that two different systems were used to take the data, so the results aren't totally apples-to-apples.
Madal RAID 5 NAS Write Performance Comparison
Write performance is literally off the chart for file sizes below 128 MB, due to the large amount of RAM in my NAS. Read performance isn't that much different than the DS508's, except where my NAS takes the lead for the 512 MB and 1 GB file sizes.
Madal RAID 5 NAS Read Performance Comparison
Given the recent price drops in pre-built NASes, I would say it is worth the hassle if:
1) You build for fun and enjoy the challenge, like I did. I had a lot of fun building it, and trying to get the pieces of the puzzle to fit.
2) You want more than 4 drives and/or 3TB of RAID5, given current drive sizes.
3) You have enough spare parts lying around to do it.
4) You want to learn Linux (or Sun or BSD or how to hack XP for RAID5)
I didn't use hardware RAID because hardware RAID boards cost a fortune, even the ones I found on e-Bay. And the cheaper ones are limited to usually 4 drives. Given what I did, with mdadm, there is really no limit to the number of drives that can be used: just throw in another PCI SATA card + drives and mdadm --grow it.