• February 22, 2025, 02:27:01 PM
  • Welcome, Guest
Please login or register.

Login with username, password and session length
Advanced search  

News:

This Forum Beta is ONLY for registered owners of D-Link products in the USA for which we have created boards at this time.

Author Topic: DSN 321 performance  (Read 5640 times)

blove

  • Guest
DSN 321 performance
« on: December 28, 2008, 06:20:43 PM »
I'm running a gig LAN with jumbo packets.
I have a DSN-321 with fw 1.01 and two 1TB WD green hard drives formatted in JBOD.

I have a performance problem when transferring large files to the D-Link.  From my main PC I can transfer a 8GB file to my Mythbuntu server (sitting next to the NAS on the same network) in 6 minutes.  The same file takes 13 minutes to transfer to the DSN-321. 

- is it the D-Link box?  I don't think so, I ran IOZone against both servers and the results were similar (around 17 MB/s for D-Link, 22 MB/s for Linux).  This does not explain why a large file takes more than twice as long on the D-Link.
- is it the drives?  Doubt it.  I've seen plenty of tests online saying 50+ MB/s is no problem for these drives.  So that doesn't explain it either.
- is it the network hardware?  Nope.  All machines involved are connected to the same switch and the D-Link status page shows a gigabit connection.  Both machines are gig lan with 7500k packets (confirmed with ping).

I'm puzzled as to why my file transfers and my IOZone tests are not matching.  At 16.5 MB/s an 8GB file should take 8 minutes to transfer, not 13.

Can anyone shed some light or share their own experiences?  I'm thinking about switching to a Synology, but I'd like to be sure the D-Link is the problem first.
I'd also like to plop a different drive in there and run some tests, but I'm worried that the D-Link will not let me put the original drives back in afterward without trying to reformat them.  Has anyone tried this?
« Last Edit: December 28, 2008, 06:22:53 PM by blove »
Logged

jumboframe

  • Level 1 Member
  • *
  • Posts: 24
Re: DSN 321 performance
« Reply #1 on: December 29, 2008, 06:53:40 AM »
blove,

What hdds are you using in the mythbuntu and pc?  I know the WD Green drives have varying rpm speeds, I think average speeds around 5400rpm.  At home I have a single 300GB WD velociraptor in one ubuntu box and 2 74GB RAID0 in another ubuntu box on a gigabit netowork without jumbo frames.  I get around 35MB/s between the two boxes.  When the DNS-321 is involved, speeds drastically drop to around 17MB/s.  I think the performance is heavily decided on the combination of the cpu and hdd used in the boxes doing the transfers.  Both my ubuntu boxes have strong cpus and hdds, where as the DNS-321 is quite basic.  That may explain your findings.
Logged

blove

  • Guest
Re: DSN 321 performance
« Reply #2 on: December 29, 2008, 10:21:17 AM »
Thank you for your post :)
My Ubuntu box has two 750 GB drives, one is a normal Seagate, the other is a 5400rpm Samsung (not raided).  Both drives will allow me to transfer an 8GB file in about 6 minutes. 
I'm fine with speeds dropping to 17 MB/s on the D-Link, that is expected behavior... but that should still allow an 8GB file to transfer in 8 minutes.  My tests confirm that transfer speeds to the D-Link are 17 MB/s, but then an 8GB file still takes 13 minutes to transfer... it doesn't add up.

My apologies for using "DSN" in my earlier post instead of "DNS"... oops.
Logged