[Anton Gorodetsky]

I was at a LAN party this weekend, it's been about 2 months since the majority of us got together to game on any large scale, programs needed updating and even just needed installing, the usual.

But, my gaming computer is out of commission. And no one else was sharing, so only one person had any data worth sharing, namely Steam files and updates for COD4, 2142, etc.

Take a guess at what happened.

The network slowed to a halt, internet basically crashed and pinged out at 200ms, all that fun stuff.

Basically, everyone was pulling a few files from one single hard drive.

Now, we know one of our bottlenecks, that of the 10/100 daisy-chain switch variety, but another one we realised was only one of our folks was being used as a 'server'

We discussed it, and we pinpointed the bottleneck being specifically the throughput of the hard drive, mostly because the person 'serving' was using SATA I, and everyone was accessing it.

But, this is where my title comes in: I have some spare hardware, and willing to invest in a couple of cheap disks. Our data is of minimal value, and if a disk dies, we can just reformat and back on our way.

All of the data we are pulling needs to be contiguous, which is what (I believe) RAID 0 is perfect for.

Basically, downtime is not an issue, basic performance on the bandwidth level is most important here.

So, can I get some help? Point out the flaws in my logic, tell me how cool of a dude I am, etc.

 

[DuckieHo]

SATA 1.5Gb/s has nothing to do with your issue. It does however sound like either a disk or a network performance issue.

You probably want to upgrade to a Gb LAN network if you will be doing file sharing. A Gb switch can be purchased for $25USD. What NIC is on the PC providing the data?

As for the HD, what kind of access was occuring?

 

[Luda]

setup an internal torrent tracker and just use bittorrent. works great at the 2 lans ive done it it at both with 50-75 people grabbing games, movies, music, etc etc from each other

 

[Anton Gorodetsky]

One of the issues IS the network, and my group of friends is throwing money together for a rather large 10/100/1000 switch.

NIC on all computers are rated for Gigabit, our networking equipment however is not.

The HD access was 5-6 people accessing Steam .gcf, ISO's, .5gb updates for 2142, etc.

Basically, gigantic chunks of data, with a single SATA drive to sate the accessers.

 

[Turnoz]

You definatly want to run gigabyte network. 10/100 has a max of 12mb/s. Im sure that his computer could send data at that speed.

Since the WAN also kicked along with every connection, it isn't the server that was the problem; its the network. Probably router since WAN dropped.

EDIT: just saw your post above. That will make a huge difference. Running a RAID 0 with two hard drives should max out the gigabit network. Running just one drive will be fine.

 

[Anton Gorodetsky]

Quote:

Originally Posted by Luda setup an internal torrent tracker and just use bittorrent. works great at the 2 lans ive done it it at both with 50-75 people grabbing games, movies, music, etc etc from each other

We considered doing this, but in our experience standard Windows networking, albeit incredibly hard to fix and to manage, is better then setting up trackers and loading .torrent files

EDIT: Also, our lan parties max out at about 15-20 people.

 

[DuckieHo]

Quote:

Originally Posted by Anton Gorodetsky One of the issues IS the network, and my group of friends is throwing money together for a rather large 10/100/1000 switch. NIC on all computers are rated for Gigabit, our networking equipment however is not. The HD access was 5-6 people accessing Steam .gcf, ISO's, .5gb updates for 2142, etc. Basically, gigantic chunks of data, with a single SATA drive to sate the accessers.

Yeah.... your issue is the network. You have a hard drive capable of 60-90MB/s. Your network connection to that hard drive is 12.5MB/s.

 

[Anton Gorodetsky]

Quote:

Originally Posted by Turnoz EDIT: just saw your post above. That will make a huge difference. Running a RAID 0 with two hard drives should max out the gigabit network. Running just one drive will be fine.

So a RAID 0 should help as long as we also get a gigabit network set up?

We got into a big argument over whether the network or the HD's run faster, which is still unresolved haha

 

[Anton Gorodetsky]

Quote:

Originally Posted by DuckieHo Yeah.... your issue is the network. You have a hard drive capable of 60-90MB/s. Your network connection to that hard drive is 12.5MB/s.

But, another issue is contiguous access, mostly due to 5-6 people also accessing the hard drive, which is a bigger reasoning for RAID 0 in my opinion

 

[DuckieHo]

Quote:

Originally Posted by Anton Gorodetsky But, another issue is contiguous access, mostly due to 5-6 people also accessing the hard drive, which is a bigger reasoning for RAID 0.

RAID0 will help since independent access request will lower the individual sequential access. The HD/array performance is not split evenly amount multiple users. A 2xRAID0 should be good enough to max out the Gb network. If you get a motherboard or NIC that supports teaming, you may want to set up a 2Gb connection to the server and get a 4xRAID0 for more performance.

 

[Anton Gorodetsky]

What you propose, DuckieHo, is one of the most beautiful sights I could imagine in a networking setting.

I am getting teary eyed ;_;

Thank you folks, your assistance has been incredible.

 

[Luda]

my Lan server box is a 4xraid0 with teamed dual gigabit connections, and it is beautiful. but i combine that with bittorrent, and we can max out the gig switches, so im moving up to fiber cards for the next large lan.

there are a couple easy to setup trackers out there, it is defiantly something to look into as the lan's grow

 

[parityboy]

One thing that caught my attention was the fact that your router's WAN connection also died. Consider that if you used a separate switch for LAN traffic, even if it was 100Mbit, it would isolate your router from the packet storm.

And yeah channel bonding ("teaming" as some call it) is a good idea, and it will leave a 2xRAID0 with breathing room, BUT it will only fully benefit you if everyone connected to your new Gb switch is also channel bonded (i.e able to pull at 2Gb/sec), which going by the numbers you quoted means a 48-port GigE switch - those are still quite pricey I think, depending on feature set. Of course, like Duckie suggested, you could team from server to switch and leave the clients on single channels.

An alternative is to use two independent connections from the server to the GigE switch, everyone else uses a single channel to the switch, and then run server software that can answer on either connection (like a web server or FTP server), or at least load balance across the connections.

That's not the same as channel bonding, by the way, although "teaming" may offer load balancing and channel bonding as either/or options, but obviously at a lower level than the server software.

 

[Anton Gorodetsky]

Well, tier 1 plan is just the purchasing of a 10/100/1000 switch, which would alleviate a lot of our problems.

But, what would be better, since the plan for the NAS is 4x250GB HD's in a RAID0 setup, teaming or channel-bonding? The difference escapes me.

 

[Mr Bear]

With that many HDD's why not raid 5?

 

[Anton Gorodetsky]

I want big bandwidth with a 1tb drive, not big bandwidth with 500gb and redundancy.

 

[Mr Bear]

Quote:

Originally Posted by Anton Gorodetsky I want big bandwidth with a 1tb drive, not big bandwidth with 500gb and redundancy.

Actually.. Raid-5 is basically like Raid-0, but it allows for more hardrives.
So, between the two.. Raid-0 = 2 drives, Raid-5 = 3 (or more) drives.

 

[Luda]

you can run more then 2 drives in a raid 0 array.

Raid 5 adds some fault tolerances, as one of the drives is designated a spare, so if a drive fails your swap in the spare drive and the raid rebuilds it self, generally considered the best mix of performance and data security.

and you would have a large amount of bandwidth on a 750GB drive, and have data security if one of them die, so you dont have to replace all that data if a drive dies.

it sounds like you want the raid drive setup in the main 'server' which would have teamed/bonded nic's hooked up to the gige side of the router. then have 100mbps connections out to all the other network drops. this is the best combination of overall performance and cost savings. since full 1gbps routers/switches are very pricey, and if everyone is pulling 1gbps off the server then your gonna run into network performance issues.

 

[Manyak]

Quote:

Originally Posted by Anton Gorodetsky Well, tier 1 plan is just the purchasing of a 10/100/1000 switch, which would alleviate a lot of our problems. But, what would be better, since the plan for the NAS is 4x250GB HD's in a RAID0 setup, teaming or channel-bonding? The difference escapes me.

Channel bonding is like RAID 0 for your network - it stripes packets across multiple connections, doubling your speed.

Teaming is also called load balancing, and instead of distributing packets it distributes software connections. So transferring a single file to a single other computer will still be limited to one gigabit connection, but if a second computer wants to access the file as well they get to use the second gigabit connection - effectively doubling the speed.

In your case, since you have multiple computers downloading from a single source (and really don't need more than 125MB/s for any one of them), you will get nearly identical results with whichever one you pick.

Teaming is easier to set up though - get a NIC that supports it, get a switch that supports it, and after a few clicks in the control panel you're good to go. Channel bonding doesn't work well unless all the PCs on the network are bonded as well.

Also, since you are mainly dealing with larger files, you may want to set up jumbo frames as well. Standard TCP packets are 1.5kB, while jumbo frames lets you increase that packet size to 9kB. This reduces the workload on the server, and increases actual speeds a bit.

Another good thing to look at would be interrupt coalescing. Normally the CPU gets interrupted after every packet is received, using this allows you to set it to only be interrupted after multiple packets, reducing overhead.

And as for the hard drives - don't look at the drive's throughput. Because you have many simultaneous accesses, you want to look for IOPS/sec - which is affected mostly by access time. So a cheap 15k RPM SAS drive, even if its throughput is a bit lower than a 7200RPM drive, will outperform it in a scenario like this. And since you are planning on RAIDing anyway, you could always get one extra SAS drive to make up for the throughput you might lose. Unless you want to get brand new high end SAS drives, then you'll probably need one drive less

. The RAID controller also plays a big part in the IOPS you get by the way, and a dedicated card will help tremendously over onboard or those cheap-o PCI cards. Check out the Perc5/i, they support SAS and sell on ebay for around $100 each, which is the best deal you're gonna find anywhere.

 

[The_Rocker]

Have a seperate PC to act as a server.

Upgrade all the switches to gigabit.

On the server PC, make sure it supports "Teaming" so that you can use 2 x 1Gb LAN's for a 2Gbs connection.

You could set up a RAID 0 array on the server PC but I doubt it would make things much faster for simply pulling files off the box. A couple of seperate discs so you could say get half the guys to map to one drive and the others to another drive...

This way you can have two seperate drives with identical files on. Half can use one drive and half can use the other. This combined with 2GB/s LAN access would be the fastest set up.