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| need filesystem tuning? http://forum.linhes.org/viewtopic.php?f=6&t=4505 |
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| Author: | rbcx [ Mon May 09, 2005 8:55 pm ] |
| Post subject: | need filesystem tuning? |
I've shuffled locations of my filesystem partitions; /myth/tv is now on a dedicated 80GB drive. However, since I've done this, I've seen that video playback from my recordings has a lot of audio and video quality issues- audio pops or skips, video has lots of artifacts or choppiness. The issues are also repeateable, so I'm assuming it occurs when the data is written, not read. I've already made sure that DMA is enabled on the drive, so I'm wondering if I need to tune the filesystem on this new partion. My old /myth/tv parition had very few inodes, and I think I'd read about needing to tune ext3 for mythtv. I've googled quite a bit; can anyone point me in the right direction? |
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| Author: | Liv2Cod [ Mon May 09, 2005 9:44 pm ] |
| Post subject: | |
Something is wrong. The filesystem isn't really strained by playing back video data. You must have some other problem. If DMA is set properly, then there must be some other reason for the poor performance. Maybe some toxic IRQ sharing or just a failing hard drive. For example, I can save two HDTV streams while playing back a third and the hard disk isn't even breathing hard. |
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| Author: | tjc [ Mon May 09, 2005 10:29 pm ] |
| Post subject: | |
Having just done the math again recently I can tell you off the top of my head that, if DMA is working right, you should only be using maybe 1/20th of the disks bandwidth. Try this on your disks: Code: for i in a b c d ; do hdparm -tT /dev/hd$i ; done
The lowest number I get is over 50Mb/sec. |
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| Author: | rbcx [ Wed May 11, 2005 7:19 pm ] |
| Post subject: | hdparm |
/dev/hdc: Timing cached reads: 1176 MB in 2.00 seconds = 586.92 MB/sec Timing buffered disk reads: 72 MB in 3.04 seconds = 23.68 MB/sec /dev/hda: Timing cached reads: 1232 MB in 2.05 seconds = 601.07 MB/sec Timing buffered disk reads: 90 MB in 3.01 seconds = 29.89 MB/sec The /myth/tv partition is on /dev/hdc1. I tried rebuilding the filesystem with mke2fs -j -O sparse_super -m0 -i 8000000 /dev/hdc1, but I still see video corruption. I'm reading and writing data at the same time right now, and according to iostat, my disk bandwith is still about 55% idle. Any other suggestions? |
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| Author: | tjc [ Wed May 11, 2005 9:45 pm ] |
| Post subject: | |
Just out of curiousity can you try this: Code: for i in a b ; do hdparm /dev/hd$i ; done and maybe this: Code: for i in a b ; do hdparm -i /dev/hd$i ; done
What does the rest of the system contain? Despite the fact that my drives report twice the speed on buffered disk reads, I suspect the HD isn't your problem unless the DMA has an issueon your MoBo. |
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| Author: | rbcx [ Thu May 12, 2005 8:30 pm ] |
| Post subject: | |
for the record, my motherboard is an ASUS A7NX8-E Deluxe. /dev/hda: multcount = 16 (on) IO_support = 1 (32-bit) unmaskirq = 1 (on) using_dma = 1 (on) keepsettings = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 65535/16/63, sectors = 80026361856, start = 0 /dev/hdc: multcount = 16 (on) IO_support = 1 (32-bit) unmaskirq = 1 (on) using_dma = 1 (on) keepsettings = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 65535/16/63, sectors = 80026361856, start = 0 /dev/hda: Model=WDC WD800JB-00CRA1, FwRev=17.07W17 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq } RawCHS=16383/16/63, TrkSize=57600, SectSize=600, ECCbytes=40 BuffType=DualPortCache, BuffSize=8192kB, MaxMultSect=16, MultSect=16 CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=156301488 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio1 pio2 pio3 pio4 DMA modes: mdma0 mdma1 mdma2 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 AdvancedPM=no WriteCache=enabled Drive conforms to: device does not report version: * signifies the current active mode /dev/hdc: Model=WDC WD800JB-00CRA1, FwRev=17.07W17 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq } RawCHS=16383/16/63, TrkSize=57600, SectSize=600, ECCbytes=40 BuffType=DualPortCache, BuffSize=8192kB, MaxMultSect=16, MultSect=16 CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=156301488 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio1 pio2 pio3 pio4 DMA modes: mdma0 mdma1 mdma2 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 AdvancedPM=no WriteCache=enabled Drive conforms to: device does not report version: * signifies the current active mode |
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| Author: | tjc [ Thu May 12, 2005 9:02 pm ] |
| Post subject: | |
Bizarroland, my hda is an earlier model of the same WD drive: Model=WDC WD800JB-00FMA0, FwRev=13.03G13 but it's timings are much faster... Code: /dev/hda:
Timing cached reads: 1380 MB in 2.00 seconds = 688.38 MB/sec Timing buffered disk reads: 148 MB in 3.10 seconds = 47.70 MB/sec Still I don't think that's the problem, and your MoBo's Nforce2 Ultra 400 / MCP-T chipset should be plenty fast. Do you boot with "noapic noioapic" to avoid serious clock drift? Do you have a lot of devices in the box or a long filter chain for playback? What are you using for a capture card? What's the rest of your hardware stack? |
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| Author: | rbcx [ Fri May 20, 2005 8:31 pm ] |
| Post subject: | |
I just added noapic noioapc to LILO and rebooted, but I see the same issue. My filter chain is whatever is stock with knoppmyth, I haven't modified it. I have 2 PVR-250's in the box, and those are the only expansion cards. Full rundown: NVidia GForce 5200MX AGP card 1GB Mushkin DDR 2100 RAM the 2x 80GB drives NEC DVD+-RW AMD Athlon XP 2200+ IRMan serial IR adapter That's all; was gonna add a WiFi card and swap the 80GB drives for a pair of SATA disks, but I don't have the money for the disks, and the WiFi card is being used in another box right now. The video and audio jerking happens whether I'm watching live TV, or just playing back the files. It looks like the kerking is actually being written into the video files themselves; when I transcode the files into, say, XVID and play them on another PC, I see and hear the exact same artifacts. Maybe its my tuner cards that need work, not my filesystem? |
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| Author: | tjc [ Fri May 20, 2005 9:23 pm ] |
| Post subject: | |
Quote: 1GB Mushkin DDR 2100 RAM Hmmm... What is your CPU core? Better yet was does this show for you?
Code: root@black:~# cat /proc/cpuinfo I seem to remember something about certain chipsets or CPUs doing better with less than 1Gb because of caching issues but it's pretty fuzzy and I'd have to hunt it down...
processor : 0 vendor_id : AuthenticAMD cpu family : 6 model : 10 model name : AMD Athlon(tm) XP 2500+ stepping : 0 cpu MHz : 1830.002 cache size : 512 KB physical id : 0 siblings : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse pni syscall mmxext 3dnowext 3dnow bogomips : 3620.86 Oh, and I'd guess the glitch is downstream from the capture card. What does "top" show if you run it during a recording? |
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| Author: | rbcx [ Fri May 20, 2005 10:11 pm ] |
| Post subject: | |
Code: sten@freya:~$ cat /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 6 model : 8 model name : AMD Athlon(tm) XP 2200+ stepping : 0 cpu MHz : 1797.104 cache size : 256 KB physical id : 0 siblings : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse pni syscall mmxext 3dnowext 3dnow bogomips : 3555.32 Code: top - 23:10:51 up 1:56, 2 users, load average: 1.35, 1.98, 2.23
Tasks: 82 total, 2 running, 80 sleeping, 0 stopped, 0 zombie Cpu(s): 35.3% us, 3.0% sy, 0.0% ni, 58.0% id, 0.3% wa, 2.0% hi, 1.3% si Mem: 1034132k total, 634768k used, 399364k free, 7424k buffers Swap: 881480k total, 16k used, 881464k free, 410356k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 7387 mythtv 15 0 227m 103m 28m S 34.9 10.3 33:57.46 mythfrontend 6891 mythtv 15 0 178m 26m 11m S 3.0 2.6 0:33.37 mythbackend 7334 root 15 0 181m 49m 13m S 2.0 4.9 2:12.98 XFree86 5005 root 5 -10 0 0 0 S 0.3 0.0 0:08.52 ivtv-enc 5065 root 5 -10 0 0 0 S 0.3 0.0 0:00.14 ivtv-enc 7692 sten 16 0 2132 1048 836 R 0.3 0.1 0:00.06 top 1 root 16 0 160 80 52 S 0.0 0.0 0:00.72 init 2 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0 3 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0 4 root 10 -5 0 0 0 S 0.0 0.0 0:00.11 events/0 5 root 10 -5 0 0 0 S 0.0 0.0 0:00.02 khelper 10 root 10 -5 0 0 0 S 0.0 0.0 0:00.00 kthread 19 root 20 -5 0 0 0 S 0.0 0.0 0:00.00 kacpid 141 root 10 -5 0 0 0 S 0.0 0.0 0:00.04 kblockd/0 193 root 20 0 0 0 0 S 0.0 0.0 0:00.00 pdflush 194 root 15 0 0 0 0 S 0.0 0.0 0:00.03 pdflush 196 root 14 -5 0 0 0 S 0.0 0.0 0:00.00 aio/0 |
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| Author: | rbcx [ Fri May 20, 2005 10:19 pm ] |
| Post subject: | |
that last reply was while I was watching live TV. here's top while recording 2 shows simultaneously: Code: top - 23:18:40 up 2:04, 2 users, load average: 1.51, 1.79, 2.02
Tasks: 82 total, 2 running, 80 sleeping, 0 stopped, 0 zombie Cpu(s): 0.3% us, 1.7% sy, 0.0% ni, 94.0% id, 3.0% wa, 1.0% hi, 0.0% si Mem: 1034132k total, 908664k used, 125468k free, 12172k buffers Swap: 881480k total, 16k used, 881464k free, 677264k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 6891 mythtv 15 0 178m 26m 11m S 1.0 2.6 0:45.18 mythbackend 5005 root 5 -10 0 0 0 S 0.3 0.0 0:10.08 ivtv-enc 5065 root 5 -10 0 0 0 S 0.3 0.0 0:01.67 ivtv-enc 1 root 16 0 160 80 52 S 0.0 0.0 0:00.72 init 2 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0 3 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0 4 root 10 -5 0 0 0 S 0.0 0.0 0:00.11 events/0 5 root 11 -5 0 0 0 S 0.0 0.0 0:00.02 khelper 10 root 10 -5 0 0 0 S 0.0 0.0 0:00.00 kthread 19 root 20 -5 0 0 0 S 0.0 0.0 0:00.00 kacpid 141 root 10 -5 0 0 0 S 0.0 0.0 0:00.04 kblockd/0 193 root 20 0 0 0 0 S 0.0 0.0 0:00.00 pdflush 194 root 15 0 0 0 0 S 0.0 0.0 0:00.03 pdflush 196 root 14 -5 0 0 0 S 0.0 0.0 0:00.00 aio/0 195 root 15 0 0 0 0 S 0.0 0.0 0:01.67 kswapd0 197 root 25 0 0 0 0 S 0.0 0.0 0:00.00 jfsIO 198 root 25 0 0 0 0 S 0.0 0.0 0:00.00 jfsCommit |
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