Very Computer

The setup basically works but saving files onto the box is crawlingly slow.  Rates of 500kb/s or less via SAMBA and even slower (50kb/s) via FTP (so I can be sure that the problem is
low-level networking, not Windoze or SAMBA).

Loading files from the server using any technology is very fast.

Looking at diagnostics the one thing that's obvious is that on "/sbin/ifconfig eth1"...

UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

RX packets:1149326 errors:0 dropped:0 overruns:20921 frame:0

TX packets:1239052 errors:0 dropped:0 overruns:0 carrier:1

collisions:0 txqueuelen:100

RX bytes:398014948 (379.5 Mb)  TX bytes:778774691 (742.6 Mb)

Interrupt:9 Base address:0xfe80

..the "OVERRUNS" figure on the "RX" section keeps going up, it's about 2% of the total packets received.  If each time a packet is lost then the whole sequence of TCP packets has to
start from the beginning again (a RESET packet is sent? not much of a TCP expert!) then that means that potentially a 100-300k file (typical for my users) might get quite difficult to
save - this is what the samba logs reflect with several attempts to save files.

Have tried both Donald Becker's 3c5x9.o and 3c90x.o drivers as provided pre-compiled in my SuSE 7.2 distro exactly the same problem with both.  (Also I've tried downloading the driver
from 3Com's site and compiling it - that one worked well for about 20 seconds then disconnected from the network completely!!)

My limited understanding might suggest a problem with either a hardware conflict (?) or the driver or the card.  The card was fine in the previous machine it was in (Win2k Pro box),
the hardware is PCI and "bus mastering" which I understand means that the network traffic is saved directly into RAM so IRQs are needed less and even on a reasonably busy machine there
should be no overruns??

Have searched FAQs and net to no avail.  Can anyone help?
(real email address is carl then the at sign then bookmanassociates.com, no spam please!!!)

Carl Peto

- Check 'hdparm' of the harddisk to see if DMA is enabled, since that
  parameter will have the most impact.  

- Put the harddisk on its own cable.

--

Linux solution for data management and processing.

Interesting, thanks.

I have two disks in the server...

desdemona:/usr/src/linux/drivers/net # mount
/dev/hda3 on / type ext2 (rw)
proc on /proc type proc (rw)
devpts on /dev/pts type devpts (rw,mode=0620,gid=5)
/dev/sda1 on /home type ext2 (rw)
/dev/sda2 on /database type ext2 (rw)
/dev/hda1 on /boot type ext2 (rw)
shmfs on /dev/shm type shm (rw)

desdemona:/usr/src/linux/drivers/net # hdparm /dev/hda

/dev/hda:
 multcount    = 32 (on)
 I/O support  =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  0 (off)
 keepsettings =  0 (off)
 nowerr       =  0 (off)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 1023/64/63, sectors = 4127760, start = 0

desdemona:/usr/src/linux/drivers/net # hdparm /dev/sda

/dev/sda:
 readonly     =  0 (off)
 geometry     = 1023/33/61, sectors = 2061108, start = 0

One of my users confirmed that network shares located on the IDE disk are
much slower to save than those on the SCSI disk which is what you'd expect
from what you've said.  Although even the SCSI disk is still noticably slow
on save (but not on read).  The SCSI disk shares a cable with a CD-ROM drive
that is virtually never used, by the way.

The IDE disk already has it's own cable but the harddisk controller is on an
expansion card that is plugged into an ISA slot, which can't be helping.

Also DMA is not enabled as you can see.

The only problem with this theory is that saving files to either hard disk
directly when in linux is virtually instantaneous (fraction of a second).
Guess it could be cacheing or something?  Although the sync command returns
instantly too.

Thanks,

Carl

(My real email is carl at bookmanassociates.com, no spam please - violators
will be reported to their ISPs!)

Quote:> /dev/sda:
> readonly     =  0 (off)
> geometry     = 1023/33/61, sectors = 2061108, start = 0

Quote:> One of my users confirmed that network shares located on the IDE disk are
> much slower to save than those on the SCSI disk which is what you'd expect
> from what you've said.  Although even the SCSI disk is still noticably slow
> on save (but not on read).  The SCSI disk shares a cable with a CD-ROM drive
> that is virtually never used, by the way.

> The IDE disk already has it's own cable but the harddisk controller is on an
> expansion card that is plugged into an ISA slot, which can't be helping.

Quote:

> Also DMA is not enabled as you can see.

> The only problem with this theory is that saving files to either hard disk
> directly when in linux is virtually instantaneous (fraction of a second).
> Guess it could be cacheing or something?  Although the sync command returns
> instantly too.

--

Linux solution for data management and processing.

In some (not all) cases, using the 3Com 3c90x driver has helped, but I
see you've tried that.

Before doing something drastic like switching disks or scrapping your
PC, do try a different type of network card, even a cheap one.

   Stuart Levy