NAS, Softraid, hardwares, needs some help.....

[Antimatter]

I have several questions which are listed below.

System spec:
5+ sata harddrive
1+ gigabit ethernet
Pentium-M or core lines cpu for softraid.

Goals:
Try to get near harddrive speed via gigabit ethernet.
This system real only purpose is to be a file server, along with some other limited stuff such as centeral logging database and so forth. But if I don't get enough money to make a real server I might burden this box with some serving duties.


1) It certainly would be cheaper to get a motherboard that supports Pentium-M or Core lines, with 5+ sata port on the motherboard, but my concern is will performance suffer? Why I'm asking this is, the sata port on the motherboard and the gigabyte ethernet port probably shares the same bus...


2) If there is going to be a performance degeration from using onboard gigabit and onboard sata ports then I would like to find a motherboard that supports PCI-X or PCI-express for the sole purpose of decedating a whole bus to the harddrive array, and another bus for the gigabit ethernet. Anyway I did find a few such as DFI 855GME-MGF, but this leaves us the problem of finding a sata controler for PCI-X or PCI-express that does not have an onboard RAID, and is well supported by linux or BSD.


3) I'm also wondering if products like these are any good Exteral drive cage, I was thinking of perhaps building the system in a shuttle case, then attaching one of those exteral drive cage to a card that accepts outside sata ports. So would those solution work, or would it be better to go for an all internal solution in an mini-tower?


Hoped system spec:
Pentium-M, Core Duo, Core 2 Duo.
5+ harddrive in a softraid by linux/bsd
Maybe a DVD burner
1+ gigabyte of memory
gigabyte ethernet
Fits in a mini-tower to med-tower.


Thanks!

 

[drizzt81]

1) In quite a few cases the SATA ports are directly connected to the southbridge, which also hosts the GbE connection. The internal southbridge bandwidth should easily be able to handle that transfer. You may want to look at the manuals of the motherboards that you are considering, since they often include diagrams detailling the connections.

2) A "good" add-in board will likely offer superior RAID-5 or 6 performance over the software raid solution that you may be looking at. The additional cache that some add-in controllers have may also be able to mask some latencies or impove multi-user performance. Since you ask specifically about non-raid add-in cards: No, there is no performance to be gained from using a add-in card over using the on-board ports of a "recent" motherboard.

Add-in cards that have a TCP offloading engine may improve performance for your data transfers. Some people suggest that Intel's server cards are faster than the commonly integrated marvell solution.

These two questions really boil down to motherboard selection. In the end, if you were to go with a nForce 2 motherboard, there is a really good chance that their integrated SATA ports are bus limited (PCI) and that -if it even existed- the same is true for the GbE port. Recent chipsets, say a board with an ICH7, have SATA and networking ports directly connected to the southbridge. For SATA, I would expect the performance to be just as good as any add-in solution, while GbE may see some improvement from getting a "good" add-in card. I suggest you visit the networking forum and ask the people over there about their preferences and experiences.

3) I cannot help you due to the lack of experience.

 

[Madwand]

2) If there is going to be a performance degeration from using onboard gigabit and onboard sata ports then I would like to find a motherboard that supports PCI-X or PCI-express for the sole purpose of decedating a whole bus to the harddrive array, and another bus for the gigabit ethernet. Anyway I did find a few such as DFI 855GME-MGF, but this leaves us the problem of finding a sata controler for PCI-X or PCI-express that does not have an onboard RAID, and is well supported by linux or BSD.

Even with on-board NICs, you have to check if they're attached to the PCI bus. Unless it explicitly says PCIe, or comes from a chipset that supports it natively (e.g. nVIDIA networking), I'd assume the worst -- that the NIC is connected via PCI, which is true for the above-linked MB. (And even some chipsets with support for native networking have been messed up in the MB implementation -- e.g. some Gigabyte 939 nForce3, with nVIDIA being connected to 10/100 only and another PCI add-on doing GbE. Why oh why?)

http://www.realtek.com.tw/products/productsView.aspx?Langid=1&PNid=13&PFid=4&Level=5&Conn=4&ProdID=5

I've been considering getting an Intel MB myself for this sort of application. The candidate at this time would be an Intel desktop board DQ965GF variant. It solves the raised issues and give a fair bit of flexibility in storage configuration / upgrade options. It doesn't support PCI-X or ECC though, for which you'd need a server-class board.

http://www.intel.com/products/motherboard/dq965gf/index.htm

Intel Q965 Express chipset
S775 Celeron / Pentium / Pentium D / Conroe; HT
Integrated graphics
Intel PCIe GbE
x16 PCIe
x1 PCIe
2x PCI
6x SATA RAID 0/1/10/5

E.g. configuration BOXDQ965GFEKR
http://www.intel.com/design/motherbd/gf/gf_available.htm

US $134 at DirectDial:
http://www.directdial.com/us/shop/item/BOXDQ965GFEKR.html

Might need some care with RAM compatibility -- see Intel's support tab.

 

[Antimatter]

drizzt81

1) Good point, I looked at the motherboard manual of the motherboard recommended by Madwand, and it looks like the gigabit and PCI-Express 1x shares the same bus, along with PATA, but I probably won't be using that bus for much other than maybe the 1x and the gigabit so it looks good to me there, then the 6x SATA connection has their own bus , so it looks good to me, plus the PCI-Express 16x slot has its own bus also so that will be good for any adding card that I may need to add on in the future, perhaps it could hold a card for eSATA, then i could later expand the array by buying a few eSATA towers and attaching it to that card....

2) I agree, but this is for a private home system, I don't need enterprise speed, because with enterprise speed comes the enterprise price, which i can't afford, which is one of the reason why I am going with a soft RAID, second reason is if the hardware RAID card itself dies, I'll need to find another one that is exactly the same so the RAID array can be read from the drives, however if i go with soft RAID, I shouldn't have an issue with that as long as the soft RAID subsystem in the kernel remains relatively stable/compatible.

And I agree with the assessment about the gigabit port, I think the onboard should be good enough, even if the onboard gigabit only gets 50% the performance of a good addin card, it is still able to get up to 60 MB/sec transfer rate, which is good enough to sustain the transfer rate for a single harddrive.... Which is the minimum that I am hoping to achieve here.

3) Probably will go with a mini-tower along with that motherboard that Madwand pointed out then worry about eSATA later.


Madwand

2) That's good point, but the motherboard you pointed out appears to have the gigabit attached to the PCI-Express 1x bus so that's good.

I like that motherboard you pointed out, and it has a pretty good price too, I'll have to research more into it, but sadly it doesn't have ECC but its for a home NAS setup, which should have reliable hardware, but price and other stuff is also a concern, so this looks like a good motherboard to me. And about the RAM, no problem I can look into that.

Thanks!

 

[unhappy_mage]

Looks like a good plan.

I seem to recall that the second half of the chipset on the Intel board linked has an x4 pci-e interface. Or rather, six, and gigE is on a seperate interface. Thus, you don't have to worry about limitations there.

Even integrated Intel nics tend to have TCP checksum offload these days. It's getting cheaper to just make them all the same rather than making the cheaper ones actually have less features.

Are you planning to use Linux? What protocol are you going to use to serve files? If it's Samba, you're going to get pretty bad performance from it by default; mess around with parameters a bit and you can improve transfer rates quite a bit with no investment.

 

[Antimatter]

1) That's good thing about the additional interface we all could always use more interfaces!

2) Even then, with a Core 2 Duo, that motherboard probably shouldn't have any issue at ALL with processing and doing general file server work.... for most things

3) Yep I'm planning on using Linux, probably NFS, consdering my laptop is linux, and my current desktop is linux, and the odds is my next desktop machine might be a mac-mini, which supports NFS....

And I'm pretty much aware about the bad default performance of Samba, I've seen plenty of posts all over the internet about people bitching about it, prior to tweaks that is