Am Montag, 17. Oktober 2011 schrieb Sthu Deus: > Thank You for Your time and answer, Martin: > >How do you copy the file? Maybe the method you use for copying uses > >small buffers and thus needlessly generated disk seeks. You might try > >using dd with bs=1M ;). > > I do this w/ mc. > > But w/ dd it is the same.
Also with bs=1M? > >> >Then also include at least the following: > >> > > >> >- hdparm -I /dev/sda | egrep -i "(model|transport:|likely > >> >used|DMA:)" (replace sda by whatever your drive is) > >> > > >> Model Number: Hitachi HTS547575A9E384 > >> > >> Transport: Serial, ATA8-AST, SATA 1.0a, SATA II > >> Extensions, SATA Rev 2.5, SATA Rev 2.6; Revision: ATA8-AST > >> > >> T13 Project D1697 Revision 0b > > > >I guess thats an 3.5 inch drive? (Don´t want to bother with looking up > >the model...). For a laptop drive above numbers could make some sense. > >Is it a 7200 or 5400 rpm drive? This could have an influence, since > >seeks could have been involved. > > No. 2.5", 5400 RPM - still I do not believe it can be satisfiable > performance for the drive. Oh, I do. I do not see more than 30000 blocks in vmstat 1 on IDE driven laptop drives. But with recent kernels it should not stall or lag that long. > >> 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 > >> > >> Advanced power management level: 128 > >> 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 > > > >Thats nice, the kernel is using DMA for accessing the drive. > > And probably, the highest? What can be a problem... Could be, but then it would like be a controller or cabling issue. I would exclude cabling issue as long as its the internal laptop drive. > >> >- lspci -nn | egrep -i "(ide|sata)" > >> > >> SATA controller [0106]: ATI Technologies Inc SB600 Non-Raid-5 > >> SATA [1002:4380] > >> > >> IDE interface [0101]: ATI Technologies Inc > >> SB600 IDE [1002:438c] > > > >Now there might be an issue. I don´t know how good this SATA > >controller works. > > OK. Then my problem can be cured by replacing the laptop only, - I do > not think the drivers will be any better since long time has passed > from the manufacture date? I am not sure about that... only a grep through kernel changelogs could reveal that. > >> >- grep -i "model name" /proc/cpuinfo > >> > >> AMD Turion(tm) 64 X2 Mobile Technology TL-52 > > > >Or do you happen to do this on a laptop drive? > > Do what? Copying the 6 GB file... but from what I understand so far: yes, you do this on a laptop drive. > >Then this might explain this issue as well... laptop drives aren´t the > >fastest. > > Even w/ such huge freezes/delays?! It is my experience that these have gotten shorter with recent kernels, but it seems your mileage varies. > >So my suggestions: > > > >- try to reduce the trigger on when the kernel starts to writeback > >data > > How do I do this? Try lower values for /proc/sys/vm/dirty_background_ratio, its the percentage of pages to be dirty at which the kernel has to start writing out data. Or alternatives try with different values for dirty_background_writes. Background for this: On machine with lots of RAM and slow drives writes can pile up that badly, that you get bulky / stalling before when the kernel then gets intro stress writing out data in order to free memory for example. Its worth an attempt... > >- try to use ionice with the IDLE priority for the copy process > > Is it manually or some tunable util.s aare available in the system? man ionice ;) Although it is my experience that it does much less of a difference than I hope for. > >- or use block i/o controller to limit the bandwith > > How do I do this? - apt-get install linux-doc-3.0.0 - cd /usr/share/doc/linux-doc-3.0.0 - find -name "*blkio*controller*" Read it, try it. Either with relative I/O weights or even by limiting the bandwidth to say 5 MB/s or so to have what ionice with IDLE scheduling class might not give you. Ciao, -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7 -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/201110191043.11449.mar...@lichtvoll.de
