topic Re: NAS 2000s poor write performance in Network Attached Storage (NAS) - Enterprise

NAS 2000s poor write performance

Jason_334 — Fri, 09 Jul 2004 12:22:55 GMT

I have a NAS 2000s with 1.6 TB storage, Raid 5, running Windows 2003 storage server. NAS 2000s is connected to the router via 1 gig full duplex router. From an XP client a 100 meg file on the old file server takes 60 seconds to load, on NAS 2000s, 4-5 minutes. I can transfer from NAS to XP client in 25 seconds. The server was setup with default settings. I have turned off NFS server and I have turned off Anti-virus software, quota, and file filter. Nothing has seemed to work. Any ideas?

Re: NAS 2000s poor write performance

RBaker — Sun, 11 Jul 2004 04:23:52 GMT

More info required:

How many (quantity not size) disks are on the old server volume and how many are on the new volume. Are you using network teaming?

Re: NAS 2000s poor write performance

Monty Phillips — Mon, 12 Jul 2004 09:17:55 GMT

Jason,

To add on to what Richard asked, have you checked your array 5i controller cache settings? It sounds like it might be set to 100% Read /0% Write. If that is the case, setting it to something like 50% Read /50% Write would help your read performance from the client side significantly (or adkust to what your environment needs).

Re: NAS 2000s poor write performance

Jason_334 — Mon, 12 Jul 2004 13:45:51 GMT

Our old file server is a DL 380 with 14 disks on the disk array and they are 36 GB SCSI disks. The array is set to Expand Priority of Low, Rebuild Priority of Medium and 100% Read and 0% Write and a Surface scan of 15. On the new NAS 2000s I have 14 disks on the disk array and they are 146 GB SCSI drives. The array, Array 5i controller, is set for Expand Priority of Low, Rebuild Priority of Low, and 25% Read and 75% write, and Surface Scan Delay of 15 seconds. What is the Surface Scan Delay do? I thought Write setting is writing data to disk and read is reading data from disk is not not correct? I was doing the network teaming, fault settings, but I turned that off.

Re: NAS 2000s poor write performance

RBaker — Tue, 13 Jul 2004 02:45:09 GMT

What controller/enclosure are you using for the old server and does that old server have NIC teaming, I've done some preliminary calculations and it all seems to point to network performance but it would be nice to exclude the disk subsystem though.

Re: NAS 2000s poor write performance

RBaker — Tue, 13 Jul 2004 03:51:05 GMT

Here's the calculations, i've made some assumptions but these should be about right.

Some bandwidth figures:
Disk bandwidth (assuming 10k drives, 15k add 30%)
Both old and new 14 drives raid5: (14-1)*8MB/s=104MB/s
Controller bandwidth old (ultra-2, 1 channel):80*0.7=56MB/s
Controller bandwidth old (ultra-2, 2 channel):2*80*0.7=112MB/s
Controller bandwidth new (ultra-3, 1 channel):160*0.7=112MB/s
NIC old (100 Mb):(100/8)*0.4=5 MB/s
NIC New (1.0625 Gb):(1.0625*1000/8)*0.4=53 MB/s
Client would yield 5MB/s(100Mb), 0.5MB (10 Mb)

From your information:
100 MB file takes 1 min on the old system: 100/60=1.7 MB/s
100 MB file takes 4 min on the new system: 100/(4*60)=0.4 MB/s
From NAS to client 100 MB file 25s:100/25=4 MB/s

I can then assume:
clients are either 100 Mb or 10 Mb (which might account for the 0.4)
Disk subsystem and caching appears to be ok

I would then conclude that:
You check the client-side NIC's are running at 100 Mb rather than 10 Mb.
At 100 Mb you should expect 1-4 MB/s : 25-100 secs for your 100 MB file
At 10 Mb 0.1-0.4 MB/s : 4-16 mins for your 100 MB file
If you are using hubs then multiply these times by the average number of active ports on the hub for worst case

If you really want to rule out the disks then monitor:
logical disk object->Average Disk queue length (less than 2)

Average disk read queue length and Average disk write queue length will assist in determining optimum cache settings

Re: NAS 2000s poor write performance

Jason_334 — Tue, 13 Jul 2004 12:12:03 GMT

On the old file server it is using a Smart Array 431 controller. The old file server is not using NIC TEAM. It is a HPNC3134 with the settings at 100/full and the rest are the default settings.

Re: NAS 2000s poor write performance

Jason_334 — Thu, 15 Jul 2004 13:53:36 GMT

I have loaded SP1 for WSS. I did performance checks for logicial disks. Average Disk Read Queue Length Low=0 Average=.12 Min=0 Max=.446. For Average Disk Write Queue Length. Low=0 Average=.01 Min=0 and Max .26. For Average Disk Queue Length. Low=0 Average=.03 Min=0 Max=03. When I connect my XP laptop to the Extreme black diamond or other servers that are connected to the Black Diamond, the transfer speeds for read/write are all under 1 minute for 100 MB file. As soon I connect to an Extreme 48 port Switch, the speeds go back to 5 minutes to write and less then 30 seconds to read. I am not a network person but why it that this server is the only one slowing down compared to my old DL 380 with Windows 2000?

Re: NAS 2000s poor write performance

RBaker — Fri, 16 Jul 2004 04:44:53 GMT

Disk figures look perfect. Not that knowedgeable about the extreme product range but I would suggest fixing the network baud rate on the NIC at various values and determining the optimum. Either that or something on the router needs tweaking.