[K12OSN] Slow performance

Eric Harrison eharrison at mail.mesd.k12.or.us
Sat Nov 12 03:00:24 UTC 2005

On Fri, 11 Nov 2005 bear2bar at netscape.net wrote:

> Hi,
> OK here are the specs;
> Server
> Dual P-III 600 Mhz
> 2 GB memory
> 30 GB IDE drive

Given the size of that drive, I assume it is an older parallel IDE
model (PATA). PATA is HORRIBLE in a terminal server. Just say NO to

I still recommend SCSI, but am softening up to Serial IDE (SATA).

Over the last couple of days I've been doing benchmarks against a
LSI Megaraid U320-1 SCSI controller with 6 72G 10K SCSI segate drives 
(~$150 each) in Raid 5 and LSI Megaraid 300-8x SATA controller with 6 
400G 7.2k SATA segate drives (~$250) in Raid 5.

The Megaraid 300-8x SATA controller with the optional battery backup
(~$400 for the controller, $150 for the battery) is about on-par with
the bare Megaraid U320-1 SCSI controller (~$200). Add the optional 
battery backup to the Megaraid U320-1 controller (~$100), and it is 
~20-40% faster than the SATA controller/drives depending on the test.
(adding the battery backup defaults each controller to a more 
aggressive write caching algorthm). Both cards use the same driver.

The SATA performance quite impressive, considing the SCSI test system
has smaller, higher RPM drives.

The SCSI setup is slightly cheaper at $1,500 vs SATA's $2,000,
but the storage capacity of the SATA setup is 4.5x greater.


> 100 mb NICs
> Workstations (Clients)
> Compaq SFF P-III, 600 Mhz
> 512 MB
> 100 mb NIC
> Cable modem connected to a router with two 100mb switches
> Sub-net 1- Windows workstations x 3
> Sub-net 2 - 10 Clients
> Clients have W2K loaded & get their IP address via the linux server
> These same clients also do a network boot to become thin clients on the linux 
> network
> Software
> K12LTSP version 4.4 with all updates
> Problem
> Launching applications either on the client or the server is very slow, 24+ 
> sec for a terminal window
> TOP shows a minimal load on the processors, max of 24% on one processor for 
> the gnome desktop, 10 - 15% for X, but usually the load is at 2 - 3%
> Any ideas or suggestions is greatly appreciated.
> thks
> norbert

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