Software RAID 5 for NAS/File Server – Need help compiling a user resource

[zzsprade]

I have researched this and changed my ideas over and over again. I turn to everyone for what guidance and experience they can offer.

For some time now I have been meaning to use my old computer hardware to setup up a machine as separate NAS for my home. The purpose of which would be sheerily for storage, and not performance (streaming media etc.)

For this exercise I am more than willing to take the performance hit and embrace a ‘software’ RAID 5 setup – due to cost of ‘hardware’ alternative with onboard XOR processing.

For such an exercise I was originally going to use the Windows XP hack for RAID 5 on my main machine. However, I am in a quest for greater functionality.

Particularly I am looking at the alternatives of Windows Server 2003 and in particular, Linux (of which I have no experience, but am very interested to develop my knowledge) on a separate box.

With recent advancements I am keen to deploy this functionality:

• Expandability – That the array size can be grown with the addition of extra drives (A particular of the recent Linux kernel as I understand). Also whether it forms space as part of the main pool.

•Better to partition the RAID 5 array with separate drives for each media type (music, tv series etc) or use as a single pool of space.

• I have seen somewhere (very vague) the option of different sized HDDs and using the normal loss in space for the extra drive (parity) as a separate partition (not as important… just for future proofing upgrades).

• To have the array be functioning/accessible across Windows machines in a home network.

• SAMBA, FTP, accessibility away from the network and other interesting options available.

• E-SATA: Peoples experience with expanding for more drives via this option.

• Windows Server 2003 vs Linux build (for the functionality purposes above)

Can everybody share their personal experiences with such a task. Links? Recommended builds of Linux etc?

This is in an effort to compile recent advancements and knowledge for such a task that I wish to share as a resource. Also to see other peoples ideas.

The specifications of the machine will be as follows:

AMD64 3000+
1Gb DDR400
4x400gb Seagate SATAII drives
1xHDD for operating system etc.

(Parts spare from recent builds etc).

My apologies for the detail, but I seem to be going around in circles and would like some clarity.

-Alex

[boykster]

I used to run an 8 drive software RAID5 array on a redhat 9 system.  Was fairly stable, but the difficulty of maintaining 8 IDE channels (1 drive per channel) was too much and I eventually had a catastrophic failure.  I ditched software RAID and went to 3ware cards and hardware raid and haven't looked back.

Some observations from my experience:

- online expansion: back when I used s-RAID, there was a tool to resize your array, but it was slow and buggy.  I never tried it

- partitions: I have always been a big fan of large single partitions.  you choose the block size when building the array, so I don't see any benefit to breaking up the partitions.  less drive mounting to deal with as well (under linux)

- diff sized drives:  with software (and even hardware) raid you can use different sized drives.  Software raid uses partitions that are all the same size to create the array, so if you had some "leftover" space on a drive, you certainly could partition and format that and use the space.  You can't use it as parity within the array however, unless the "extra" space partition is large enough to be added as a member of the array, but I would advise doing that.

- access from windows network -> samba is your friend.

- ftp: linux has numerous ftp options available for remote access.

- e-sata: I see no reason why external drives couldn't be used for a software raid array, however I would be wary of having devices not powered by the same power-supply or switch members of an array.  If one accidentally gets powered down, it gets kicked from the array.

- win2k3 vs linux:  no experience under win2k3 for me with software raid, so no input.  My experience was all with linux


your hardware specs are more than adequate for your build.  one of my 3ware file servers up until just recently was a 1ghz duron with 1gig of ram.

[Samstag]

I have a system running Slackware linux with an 8x250G SATA-I array.  It's running on a 2000MHz Sempron with only 256M memory and two 4-port SATA cards.  I would underclock it to cut down on heat and power use if the motherboard supported it.

I've never tried expanding the array so I can't comment on that.  I know you can mix various size drives but I was under the impression that the extra space was pretty much wasted.  I use Samba and ftp for streaming and moving files around.  I don't have a monitor on it but just telnet in to shut it down.  I've never considered external SATA but in general I would prefer to have all the storage internal.  I found a nice $100 tower that easily holds my 9 disks (I used an old XBOX IDE disk for the OS).

As for Windows vs Linux, I think it'd be a little easier to set it up under Windows 2003 and it will probably run great on your AMD64.  If you don't already have the CPU, though, I'd get something older and cheaper and run Linux.

I'd be happy to help you out further if you decide to go the Linux route.

[patrickl]

I used file servers for years. Always drama. I'd say Linux was worst of all to use. I tried software raid (both with Windows 2000 and Linux), but when you have a problem with a disk I had trouble getting things to work again. Tried hardware raid, but for instance, Linux would not support the card after a while anymore. Besides, there was often something going wrong with installing updates. Supporting a linux server can be pretty aggravating. Also, a server PC's use a lot of electricity (you should add up how much that costs, it really is a lot over a year if you keep em running 24/7) Imagine a 200 to 300 watt lamp burning all the time. Not to mention the noise and even the heat coming from theis thing.

So I was pretty much fed up and after reading a review I switched over to a ReadyNAS. Greatest decision I ever made (on that subject). Just stick in the disks and everything works. Want it bigger, just replace the disks one by one. Or add a disk if you have a slot free still.

For PC's I use a tapeless backup. This is a disk mirroring unit. Just plugs in as one drive and you put 2 disks in it. the disks are automatically synchronized. If one disks breaks the other disk still runs (with other forms of RAID you need the original hardware/software to keep running it)

[str1der]

I highly recommend UnRaid. I set up a NAS server about 3 weeks ago of about 2 TB. This thing is so flexible. I'm streaming my DVDs and mp3s off of it and it works great. It's not really raid 5 it's more of a hybrid 4. It uses a parity drive but doesn't use stripping. What I like about it is you could lose 2 drives at once and yes you would lose some data  but all the data on the remaining drives would be fine. Take a look and I think you'll be impressed.

http://www.lime-technology.com/