system slowdown with any IO
Hi there guys.
I've had an issue with my Ubuntu system since version 7 or so and I have not been able to track it down with each Ubuntu dist upgrade I have done over time.
The system slows to a creeping halt on any IO, usually disk activity, and I can't figure out why. I have determined it's not just my hard drive (SATA/nvidia chipset) because writing to a USB flash drive also causes the slowdown.
IOwait goes through the roof, but as to my understanding high IOwait basically means the disk is the bottleneck and thats acceptable most of the time.
Now there's no speed issue with the drives my hard drives are fast as bolts: Even hdparm shows it:
Now, interestingly when doing these tests the system slows down (including mouse cursor, any audio playing or videos) when doing these tests. It completely stops momentarily while doing the second test (the straight disk read)Code:/dev/sda: Timing cached reads: 1294 MB in 2.00 seconds = 647.06 MB/sec Timing buffered disk reads: 208 MB in 3.10 seconds = 67.18 MB/sec
My Ubuntu version is 9.10, and my chipset is nForce4 (uses sata_nv for disk access, but like I said this happens on flash too).
* I have tried turning off swap. This only helps as much as the writes/reads to swap aren't happening.. but the issue still remains. Swappiness is now on 3 for what its worth.
* I have tried using different io schedulers (noop, etc) on my hard drive with no difference.
** With the little effect of schedulers + it being on multiple unrelated drives I suspect its not related to my drives.. but the only troubleshooting tools I know are for hard drives.
Questions:
* What else can I do to narrow down the issue?
* What, if anything, changed during the switch from 6.10 to 7.04 related to io?
* What tools can I use? Please halp.. this is terrible. For so long I have had stuttering on my VLC when I hit play when the file is loaded into RAM.
Here is my Disk controller as listedin lspci:
And here's my hard drive info (from hdparm) for what its worth:Code:00:07.0 IDE interface: nVidia Corporation CK804 Serial ATA Controller (rev f3) (prog-if 85 [Master SecO PriO]) Subsystem: Albatron Corp. Device 3404 Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 23 I/O ports at 09f0 [size=8] I/O ports at 0bf0 [size=4] I/O ports at 0970 [size=8] I/O ports at 0b70 [size=4] I/O ports at cc00 [size=16] Memory at febfb000 (32-bit, non-prefetchable) [size=4K] Capabilities: [44] Power Management version 2 Kernel driver in use: sata_nv 00:08.0 IDE interface: nVidia Corporation CK804 Serial ATA Controller (rev f3) (prog-if 85 [Master SecO PriO]) Subsystem: Albatron Corp. Device 3404 Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 22 I/O ports at 09e0 [size=8] I/O ports at 0be0 [size=4] I/O ports at 0960 [size=8] I/O ports at 0b60 [size=4] I/O ports at b800 [size=16] Memory at febfa000 (32-bit, non-prefetchable) [size=4K] Capabilities: [44] Power Management version 2 Kernel driver in use: sata_nv
Ubuntu 9.10:Code:/dev/sda: ATA device, with non-removable media Model Number: ST31000340AS Serial Number: 9QJ0TPES Firmware Revision: SD15 Transport: Serial Standards: Used: unknown (minor revision code 0x0029) Supported: 8 7 6 5 Likely used: 8 Configuration: Logical max current cylinders 16383 16383 heads 16 16 sectors/track 63 63 -- CHS current addressable sectors: 16514064 LBA user addressable sectors: 268435455 LBA48 user addressable sectors: 1953525168 Logical/Physical Sector size: 512 bytes device size with M = 1024*1024: 953869 MBytes device size with M = 1000*1000: 1000204 MBytes (1000 GB) cache/buffer size = unknown Nominal Media Rotation Rate: 7200 Capabilities: LBA, IORDY(can be disabled) Queue depth: 32 Standby timer values: spec'd by Standard, no device specific minimum R/W multiple sector transfer: Max = 16 Current = 16 Recommended acoustic management value: 254, current value: 0 DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6 Cycle time: min=120ns recommended=120ns PIO: pio0 pio1 pio2 pio3 pio4 Cycle time: no flow control=120ns IORDY flow control=120ns Commands/features: Enabled Supported: * SMART feature set Security Mode feature set * Power Management feature set * Write cache * Look-ahead * Host Protected Area feature set * WRITE_BUFFER command * READ_BUFFER command * DOWNLOAD_MICROCODE SET_MAX security extension * 48-bit Address feature set * Device Configuration Overlay feature set * Mandatory FLUSH_CACHE * FLUSH_CACHE_EXT * SMART error logging * SMART self-test * General Purpose Logging feature set * 64-bit World wide name * Write-Read-Verify feature set * WRITE_UNCORRECTABLE_EXT command * {READ,WRITE}_DMA_EXT_GPL commands * Gen1 signaling speed (1.5Gb/s) * Native Command Queueing (NCQ) * Phy event counters * Software settings preservation * SMART Command Transport (SCT) feature set * SCT Long Sector Access (AC1) * SCT Error Recovery Control (AC3) * SCT Features Control (AC4) * SCT Data Tables (AC5) unknown 206[12] (vendor specific) Security: Master password revision code = 65534 supported not enabled not locked not frozen not expired: security count supported: enhanced erase 202min for SECURITY ERASE UNIT. 202min for ENHANCED SECURITY ERASE UNIT. Logical Unit WWN Device Identifier: 5000c5000cd43ee0 NAA : 5 IEEE OUI : 000c50 Unique ID : 00cd43ee0 Checksum: correct
Linux version 2.6.31-21-generic (buildd@rothera) (gcc version 4.4.1 (Ubuntu 4.4.1-4ubuntu9) ) #59-Ubuntu SMP Wed Mar 24 07:28:56 UTC 2010
AMD Athlon 64: 2ghz
1GB dual channel ram
1TB seagate barracuda.
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