My box is based on the (very) old SIS K7S5A motherboard with the latest bios available for this m/b installed. The system's CPU is a Duron 800MHz and the box has 1262MB of RAM. I have installed Slackware 11 with the 18.104.22.168 kernel (from /extra).
The m/b does not support USB2.0, therefore, I've installed a USB2.0 PCI card. I don't remember the exact model of the card (I have to open the box to find it out, unless there is another way (?)), but I think it is based on VIA-chipset. In any case when I bought the card I remember it stated on the box that it was linux compatible.
The external disk is a Western Digital essential 250GB. Its power supply is external and it is connected on the machine through the PCI card I mentioned earlier. I am certain that there is no problem with the power supply, or with the USB cables. So there has to be something else.
I've noticed that if I set max_sectors to 64:
echo 64 >/sys/block/sda/device/max_sectors
the disk seems to work without those nasty messages in /var/log/messages. But is this the correct thing to do, or there is a better solution?
BTW, do I have a performance penalty by changing this setting from 240 to 64, or the performance loss is negligible for everyday use?