Boxing off NAS

[turbonapkin]

When we are considering the common domestic form of network attached storage which is becoming more prevalent in households every day, are we not simply adding further processing between source data and memory in the form of network and application level protocols and therefore encouraging increased latency and introducing new potential bottlenecks?

Considering the intensely bursty nature of wow's read requests my gut feeling would be to stick with direct attached storage but I would be very interested to see how joe bloe's acme nas handles five instances of wow loading into dalaran. Gigabit would be a must, I reckon.

[Ellusionist]

When we are considering the common domestic form of network attached storage which is becoming more prevalent in households every day, are we not simply adding further processing between source data and memory in the form of network and application level protocols and therefore encouraging increased latency and introducing new potential bottlenecks?

Considering the intensely bursty nature of wow's read requests my gut feeling would be to stick with direct attached storage but I would be very interested to see how joe bloe's acme nas handles five instances of wow loading into dalaran. Gigabit would be a must, I reckon.

Household NAS =/= Datacenter NAS

Sure, they do the same thing, but they aren't even remotely comparable performance wise.

This is very very true. Most enterprise level NAS equipment has 2+ gigabit ports onboard. Let me rephrase that: The better performing units that would work for this application would need dual ethernet ports. The rack mountable units I've seen cost $6,000.

I would say it's almost not worth it, but that depends on one's annual income. We do play (and pay for) multiple copies of World of Warcraft, y'know. We're a little crazy at least.

A cheaper way to do it would be using a Dell PowerEdge server. Some of those have dual ports, also. You can find those for way less than $1,000.00 on fleaBay.

[turbonapkin]

...common domestic form of network attached storage...

Household NAS =/= Datacenter NAS

Sure, they do the same thing, but they aren't even remotely comparable performance wise.

I'm sure you are very right, however I was referring specifically to the layman category i.e. the 99.9% of people here who might consider dropping a couple hundred bucks on a domestic nas device. Looking at enterprise solutions seems a moot point to me, unless you happen to have access to some juicy kit on a permanent basis!

[leukos]

I've managed to secure some additional hardware towards the end of this week/next week to gather some additional information on the concept of using an ISCSI target to store the boot disk (a "Boot From SAN" configuration) and the Warcraft installation of multiple clients. I'm not expecting any surprises for the boot disk portion (there really isn't anything new there), but do want to verify "good-enough" performance can be achieved for the time it takes to zone-in (screen loading) in Warcraft. This isn't about breaking any speed records - it won't.

The "NAS" will be a box running OpenSolaris 2008.11 using the COMSTAR ISCSI Target, configured with 2 - 3 7500 RPM hard drives. The "NAS" will have between 4 - 8 GB of RAM. At this point, I don't know if I am going to have a spare SSD to serve as an L2ARC, but I don't think it will really be necessary. I'm only going to step the "NAS" box up to multiple 1 GB ethernet connections if initial testing shows it is required, and will probably be looking at multipathing support in the COMSTAR ISCSI Target and Microsoft MPIO before an LACP connection between the NAS and the switch. The ethernet switch have Jumbo frames enabled. I think this configuration will represent about as good as a "Home NAS/SAN" can get without spending an unreasonable amount of money (for my values of unreasonable).

The performance counters I am interested in, and will be logging, on the clients include:

Disk sec/Read
Disk sec/Write
Disk writes/sec
Disk reads/sec
Disk read bytes/sec
disk write bytes/sec
various CPU and interrupt counters
Network read bytes/sec
Network write bytes/sec
Network packets incoming/sec
Network packets outgoing/sec


I may also monitor similar counters on the "NAS," I haven't decided yet how much time I want to devote to this.

Keep in mind, I am not looking at this setup for the "fastest" configuration, but a good enough configuration. I already know Warcraft will push my single 7200-RPM SATA Drive to 50 - 60 MB/s on initial zone in.


If you have any interest in this concept and would like certain easily obtainable information while I have the hardware setup, please let me know. Please be aware that "best practice" and "manufacturer's recommended configuration" decided to take an extended lunch break for this configuration.

[Ellusionist]

Just seems like a lot of work to me.

There are "conventional" multiboxing methods (just one box) that work fine. No need to reinvent the wheel.

My $0.02:
1) I don't see the need for 4-8GB RAM in an NAS. That's like putting 1GB RAM in a printer. It's just not needed.
2) If you're going SCSI, why not go 10,000 RPM? The extra 300RPM you're gaining will definitely make your project worth zilch. (7200RPM Conventional SATA [Non-NAS] --> 7500RPM [NAS])

[leukos]

Just seems like a lot of work to me

1) I don't see the need for 4-8GB RAM in an NAS. That's like putting 1GB RAM in a printer. It's just not needed.
2) If you're going SCSI, why not go 10,000 RPM? The extra 300RPM you're gaining will definitely make your project worth zilch. (7200RPM Conventional SATA [Non-NAS] --> 7500RPM [NAS])

In my case, my existing home file server fills several purposes; backup location for TimeMachine for a couple Macs, backup location for a Vista box, a couple Linux servers, one lone Windows 2003 server (don't ask), central storage for source control, other files, central media library, central location for a tape drive. I greatly enjoy the flexibility of being able to have a computer die for no apparent reason and lose no data.

The purpose for that RAM is to keep the recent disk blocks in memory so a future request in handled from memory instead of a read from disk. Multiple machines requesting the same data blocks for the boot up of the operating system and those .MPQ files could then be serviced by memory instead of disk. While this low latency/high bandwidth working set is increasingly less important with a single 1 GB ethernet connection there is a more important driving factor - we're a community of luxuries and the smallest RAM module I have is 2GB.

The 7500 RPM drive was a typo, it should have read 7200 RPM - it was late, and still is.

[Ozbert]

I have a NetGear ReadyNAS Duo at home and I wouldn't dream of trying to multibox from it. It's just too slow compared with local disks.

When copying a large file to it, I get about 25MB/sec transfer over a gigabit LAN which is probably about one third of the typical speed of a SATA-150 hard disks. Access times seem pretty slow too. I expect that having multiple copies of WoW trying to read data from a NAS would be horrendously slow and laggy.

[Mukade]

A cheaper way to do it would be using a Dell PowerEdge server. Some of those have dual ports, also. You can find those for way less than $1,000.00 on fleaBay.

XD

I've actually got a PE1950 sat under my couch. It failed to make it to colo when I started playing WoW, and gave up on the idea of running an FPS game server.

I'm sure with a full set of 8xSSDs in RAID0 hooked up to it's PERC 5i it would make one hell of a NAS, and would easily saturate the 2 gigabit ports on my 780i based desktop, as I was lucky enough to get the TCP offload key with it (so it basically has something like the killer NIC in it doing all the network processing).

The only problem is, it's a bit loud.