homebrew server with faster writes than reads

[zedpol]

So I have a via c7d running at 1ghz with a 1gigabit nic in it. I recently installed ubuntu server with webmin on it. Currently just running one drive but I was doing some speed tests and i can write to the server at about 25-30mb/s but reads only clock around 10-15mb/s. Anyone have an idea where to start looking why this is happening?

Thanks,
Z

 

[thiggins]

Depends on how you are measuring performance and what size files you are using for testing.

For writes, you could be seeing cached behavior. Read performance usually is more indicative of a NAS/server's true hardware-limited performance.

 

[00Roush]

Depends on how you are measuring performance and what size files you are using for testing.

For writes, you could be seeing cached behavior. Read performance usually is more indicative of a NAS/server's true hardware-limited performance.

I bet that is what is happening. When you are writing to the server the data is able to be written directly to memory then it gets written to the disk. When reading from the server the data is being read off the disk and written to the network with minimal buffering. My old home servers (500 Mhz AMD and 1 Ghz intel) used to have similar problems due to not having enough processing power. Check your cpu usage on the server. My thought is you might not have enough cpu power. You also could check to see if you network card supports offloading features as this can lower cpu usage.

Other things that might be holding you back could be network drivers or Samba settings on your server.

00Roush

 

[zedpol]

thanks, to both of you. I'll do some more work and see what I can track down. On a side note the more work I do with my via c7 the less I'm impressed with it. Thiggins, I'm going to be very curious to see what you think of the artigo a2000 especially where freenas and ubuntu server is concerned.

Z

 

[thiggins]

Thiggins, I'm going to be very curious to see what you think of the artigo a2000 especially where freenas and ubuntu server is concerned.

It came in the other day, but I haven't had time to fire it up yet. Probably won't for another few weeks.

 

[zedpol]

resolved

so after doing some investigation i figured my problem was a very slow hard drive. I had some 2.5 inch laptop drive that topped out at 40mb/s (hard drive speed test) so i replaced it with a WD green 1tb drive which clocks in at 70mb/s. I now get reads and writes in the 30-40 mb/s range which I am very happy with. My first iteration with this server was 6mb/s with a very poorly configured ubuntu 6.1 and 100 megabit NIC. I then upgraded to 7.1 with a 1gb NIC and still poorly configuredwhich clocked in around 10-12 and now ubuntu server i8.1 and the new hd is hitting 30-40 mb/s up and down. For those that are interested

MSI axis via c7 1ghz
1gb ram
1tb green cavier hd
realtek 1gb nic

total system power 31 watts idle..max it ever hits is 32 watts.

I think total cost was around 350 dollars. Now i'm working on FTP, Backup, itunes server etc.

Z

my experience has basically shown me...way cheaper to get exactly what you want if you build it yourself. Takes way more time, and is potentially way more frustrating. If you want something that just works buy an out of the box NAS

 

[dsc106]

Zedpool,

Thanks for sharing. I am having a similiar problem - actually about the same speeds as you mentioned for read/write in your first post.

However, at times - copying the same file, depending on when I do it - the read speeds can jump to 20 MB/S and hang out around there. Don't know why or what.

My hardware/software is:

- Athlon 3700+ socket 939
- 1gb RAM
- Onboard Gigabit LAN
- 1.5tb Seagate SATA HDD (brand new)

Ubuntu 8.10 desktop + Webmin
Sharing via Samba

When you mentioned "poorly configured" - what did you mean?

Any ideas what could be causing this problem for me? Is there a guide somewhere to setting everything up ideally?

Thanks!

 

[dsc106]

also, how did you measure how much power the system was drawing?

 

[dsc106]

One more thing - I looked at webmin after writing 100gb to the NAS. The average was 88% CPU utilization, with a peak around 98% ... my processor, again, is a single core Athlon 3700+ socket 939 AMD64.

I didn't realize this was so processor intensive... could this be a limiting factor for me? Do I need a dual core processor like a Core2duo?

 

[zedpol]

Poorly Configured
- Well, I had installed ubuntu desktop which was way too much for my little processor. I also had tried installing some of VIA's drivers which just totally screwed up my system and killed my hard drive performance. Do you use your computer as a desktop? if not I'd install ubuntu server. Worked way better for me

Measure power
- there is a handy little thing called killawatt that i bought from amazon.com

Processor
- So i would be suprised if your processor wasn't up to the task. You have a pretty powerful processor. My vote witout knowing much is to try ubuntu server and see how that works for you. The other thing is are you testing with multiple small files or one large file? Jumbo frames?

Good luck,
z