[Samba] Slow sequential write on Samba drive

[Don]

Hi,

I am experiencing very slow writes over samba.  We have a modest linux 
network (about 6 servers) and a medium sized office (20-30 windows 
boxes).  We have had a single linux file server that has done us yeoman 
service for several years.  It is running RH 7.3.  I am trying to set up 
the next generation file server with a huge (to me anyway) 2TB Promise 
VTrak 12110 RAID disk.  I've installed Fedora Core 3 and got the file 
server up and running and it works fine... except it seemed slower than 
the older system.

So, I downloaded "Performance Test" from www.passmark.com that tests 
things like hard drive speeds under Windows.  What the test told me was:

OLD SERVER
sequential read:   6.2 MB/s
sequential write: 6.4 MB/s
random seek + RW: 2 MB/s

NEW SERVER
sequential read:   8.9 MB/s
sequential write: 0.38 MB/s           <=====   *OUCH!!!*
random seek + RW: 15.9 MB/s

So, the read time is good, its just the sequential write time that 
really sucks.  What I observed while running this test was the CPU went 
up to 99% using "top" during the write time.

The new server is a Dell rack-mount server with a Xeon 2.8GHz CPU with 
2G of RAM.  My smb.conf is below.

I don't really know what I'm doing in debugging Samba... its always 
worked fine for me in the past and I've never experienced this kind of 
problem so I'm not sure where to start.

Any advice would be appreciated!!

Don


#======================= Global Settings 
=====================================
[global]

        netbios aliases = fs3 work2fs
        workgroup = pgr
        server string = Samba Server

        log file = /var/log/samba/%m.log
        max log size = 50

        smb passwd file = /usr/local/samba/private/smbpasswd
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        name resolve order = wins host lmhosts bcast
        dns proxy = no
        preserve case = yes
        short preserve case = yes

#============================ Share Definitions 
==============================
        idmap uid = 16777216-33554431
        idmap gid = 16777216-33554431
        template shell = /bin/false
        username map = /etc/samba/smbusers
        password server = None
        winbind use default domain = no
        guest ok = yes

[sample]
        comment = Sample Disk
        path = /work/work2
        writeable = yes
        guest ok = yes
        printable = no