Bug 77564
Summary: | UDMA causes serious filesystem/hdd lag | ||
---|---|---|---|
Product: | [Retired] Red Hat Linux | Reporter: | Chris Pauly <quiff> |
Component: | kernel | Assignee: | Arjan van de Ven <arjanv> |
Status: | CLOSED WORKSFORME | QA Contact: | Brian Brock <bbrock> |
Severity: | medium | Docs Contact: | |
Priority: | medium | ||
Version: | 8.0 | ||
Target Milestone: | --- | ||
Target Release: | --- | ||
Hardware: | athlon | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | Doc Type: | Bug Fix | |
Doc Text: | Story Points: | --- | |
Clone Of: | Environment: | ||
Last Closed: | 2002-11-13 12:08:00 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
Chris Pauly
2002-11-09 09:03:33 UTC
this is funny since the 7.3 update kernel is very identical to the 8.0 update kernel ;( Yeah, i thought they looked pretty identical, which is why i'm puzzled as to whether this is even a kernel bug. :( Well.. I was busy up until today so i haven't been able to test more until now. Now i find that i have the same problem again in RedHat 7.3 - up2date'd or with the original rpms (but not a fresh install, just rpm -U --oldpackage back to the original rpms). It *was* working fine before i did more post-install configuration, which brings me to believe i've done something to the BIOS, or RedHat has done something funky with my configuration after i installed more stuff. I have encountered a problem in the past with installed programs (rp-pppoe, in fact) stomping over the kernel, causing performance issues and forcing me to reboot (even killing the program won't work), so i'm not going to ignore the possibility that something has fiddled with settings or is running at startup and causing problems with the kernel. Not sure if it means much, but some relevant dmesg output is: Uniform Multi-Platform E-IDE driver Revision: 6.31 ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx VP_IDE: IDE controller on PCI bus 00 dev 21 VP_IDE: chipset revision 6 VP_IDE: not 100% native mode: will probe irqs later ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx VP_IDE: VIA vt82c686b (rev 40) IDE UDMA100 controller on pci00:04.1 ide0: BM-DMA at 0xd800-0xd807, BIOS settings: hda:DMA, hdb:pio ide1: BM-DMA at 0xd808-0xd80f, BIOS settings: hdc:DMA, hdd:pio hda: QUANTUM FIREBALLP KA9.1, ATA DISK drive hdc: MAXTOR 6L080J4, ATA DISK drive ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 ide1 at 0x170-0x177,0x376 on irq 15 hda: 18041184 sectors (9237 MB) w/371KiB Cache, CHS=1123/255/63, (U)DMA hdc: 156355584 sectors (80054 MB) w/1819KiB Cache, CHS=155114/16/63, UDMA(100) Does "VP_IDE: not 100% native mode: will probe irqs later" mean anything bad? I'll continue testing. Please let me know if there's a specific way i can test or change some useful settings. Is it worth installing some older or newer kernels (rawhide maybe? or build a new kernel directly from kernel.org?) and see if they work? Ok, nevermind, might as well close this bug. I've narrowed it down even further and it turns out that it's yet *another* bad Maxtor product. Probably not a faulty drive, just Maxtor's terrible products. I've had nothing but problems with them in the past. This drive didn't work properly in Windows to start with so i moved it to Linux for storage in hope that it'd work well. I tested the Maxtor and Quantum drives on a KT333 motherboard and they acted the same. The Maxtor's problems are compounded by ext3's journaling. When i mount the partitions on both drives as ext2, the Quantum goes a solid 9.5-11.5MB/s in both directions (read/write) in multiple tests of ~700MB files - absolutely no problem at all even in udma66. With ext3 though it dips every ~5 seconds a little when the journal/buffer is flushed (i guess? honestly i don't know much about journaling) and gives somewhat slower performance (but acceptable and bug-free). However, the Maxtor and ext2 start to have problems after about 10 seconds of writing ~9MB/s. It falls down to about 0.5-2MB/s, hovering up and down between the two. If i abort the transfer and quickly delete the file, delete takes up to a minute to complete, whereas on the Quantum drive, deletion is instant. In ext3, the 9MB/s write spurts end after a few seconds and sink to zero throughput for a few seconds, then repeats. Reading from Maxtor in ext2 or ext3 works like writing in ext3, it goes at 9MB/s for a few seconds, then 0MB/s for a few seconds, and so on. Sorry for the hassle. The lesson? Don't by anything Maxtor. :) |