Dolda2000

I recently bought a Promise Ultra100 TX2 ATA controller card and an accompanying WDC 120GB UDMA100 8MB Cache HDD for use as my NFS home dirs. (Yes, I've compiled the kernel driver for the chipset)
I thought that would be great, but so far I've run in to one big problem. When I try and write much data (>5MB or so) to the disk in a bulk transfer, the kernel spits errors on me:
That slows down the disk tremendously. When I read from the disk, there are no problems at all.
The hardware is plugged in to an OLD computer (-98 or so, Dell, 166 MHz). Not the oldest one I use as server, though.

Now, I've already mailed Promise about this, I mainly wanted to check if someone else has had similar experiences and solved them, in case they can't fix it for me.

genlee

Does this happen when writing over nfs or localy?

genlee

Blah, hit the reply button on accident. Anyway at my previous work, we added a promise ide raid card to our nfs server(rh 7.3) which caused the kernel to spit out numerous disk errors even though the hds works correctly which caused severe performance problems during write. Most of the problems we had was when writing over nfs but occasionally we did have errors when moving large amounts of files localy. We installed a 3ware Escalade 7500 and haven't had a problem since. We did see a nice increase in read performace from this card, probably the best I have seen in awhile for ide.

Dolda2000

I haven't done too exhaustive testing, but I haven't noticed any immediate difference between transferring over NFS and locally.
If anything, I was thinking it was something about this 8MB cache on the hard drive (almost all IDE drives have 2MB cache), since the first message always seems to come when the file reaches about 8 to 10 MB. I don't really see how 8MB cache would do anything like that, but then I'm not an IDE expert really.
Of course, as you say, there doesn't really seem to be anything wrong with the disk or anything, except that these errors slow down access terribly. While the kernel is resetting the drive, nothing can be either read or written to that device.

genlee

Do you have another ide controller you can test the drive on? I would try that but I have had bad problems with promise and linux. We used 8MB cache hds as well in our nfs server and they work without any problems.

Dolda2000

I guess I should do that, it's just that my only computer that's able to do that natively (w/o the Promise card) has some other IDE problems. Not with the IDE chipset, but with the other drives. But I'll probably give it a try.
I have discovered other peculiar things, though, that I'll check out first. The kernel symbols that are specific to the driver for this Promise card (pdc202xx*) can be found in the /boot/vmlinux file with nm, but I can't find them in /proc/ksyms. I now that I replaced the vmlinuz file, too, so I don't really understand why, but the /proc/ide/pdc202xx file that should also be there isn't, too, so it would seem that somehow the driver didn't get compiled into the kernel anyway.

Dolda2000

I can't believe how stupid I was!
You know what? When I recompiled my kernel, I ran "make". Do you see it yet? If not, does "make bzImage" ring a bell, maybe?
Anyway, it works flawlessly now.