Hi On Wed, Jun 04, 2014 at 08:49:44AM +0200, b-m...@gmx.ch wrote: > Hi, > > Some weeks ago I installed Testing on my wife's iMac [1] from 2008. > Unfortunately it has one issue: > > There are irregular periods of very high %wa, maybe 3-5 times per hour, not > directly related to a certain user action. They last for some seconds up to > even a minute or so and render the machine unusable for that time. top shows > %wa > of 80 or 90%, load can go up to 9 on this dual core machine, iotop shows only > a > few KB/s.
High wait-for-IO combined with very little disk throughput usually points towards disk problems... Anything interesting from e.g. "iostat -kNx" ? That should tell you which disk and partition is suffering. (Or if you already think you know, this should confirm it) > > I already added pcie_aspm=off to the boot options which seems to help, > but I still see this I/O hangs (without, I had about 10+ hangs per hour). > > Any idea what could cause these blockings? How can I find out more? I use > Linux > for 15+ years but I never saw such things... and I want to show my > wife, that Linux is the better OS, of course... ;-) My first call would be the kernel logs. IIRC in the default syslog config this goes to /var/log/kern.log, but you can see the most recent output with e.g. "dmesg" or "dmesg -T" Combine this with the disk-related snippets from /var/log/dmesg (which has the kernel output from boot) and you may see further clues... Which kernel are you using? Stock kernel, or self-compiled? 32bit? 64bit? The firmware version may also be relevant here. > > Aside from that issue everything runs quite nicely. > > Thanks & best regards, > Bernd > > [1] iMac 8,1: 2008, Core 2 Duo 2.8 GHz, GB RAM, 500 GB WD HDD, ATI Radeon HD > 2600 PRO (PCIe) Looks similar to this one? http://www.odi.ch/prog/macbookpro/#3 Hope this helps -- Karl E. Jorgensen -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20140604205400.GB9871@hawking