On Monday, January 09, 2012 22:09 -0500 On Behalf Of NeilBrown < linux-raid-owner@xxxxxxxxxxxxxxx> wrote: > On Mon, 09 Jan 2012 21:20:39 -0500 Bobby Kent <bpkent@xxxxxxxxxxxxxxxxxxxx> > wrote: > >> Is Used Dev Space a measure of the capacity on each member device used by the array? > > Yes. > > NeilBrown Hey NeilBrown, Many thanks for clearing that up. On the metadata question the mdadm man page at http://linux.die.net/man/8/mdadm implies that the driving criteria for upgrading from 0.90 is use of HDDs with > 2 TB capacity or > 28 HDDs within a raid device, neither of which are in my current plans, though I imagine at some point I'll purchase larger HDDs. Are there any other factors I should consider (e.g. kernel version compatibility)? In my previous mail I might have been a little clearer in describing the hangs/lock ups I was experiencing, as there may have been an unintended implication that md was somehow at fault. What I observed was that after several hours of uptime the system would hang/lock up, nothing was written to syslog, the desktop froze (mouse unresponsive, clock did not advance, etc), network unresponsive (could not get a ping response), HDD access LED was on. Hitting the reset button appeared to be my only option to get back to a working system (on one occasion my machine was left in this state for 90+ mins). I am typically unwilling to hit the reset button, I probably did it more times last week (3 times after the "downgrading" to 3.0.6 kernel) than in the prior 18 months. It was the LED that lead me to wonder about a resync following a hard stop, and after discovering resyncs had not completed I left my machine booted to the login prompt (rather than logged into in KDE) one night. To further muddy the waters the lock ups occurred while I was making some configuration changes in order to implement real time processing for audio software. I've backed these out prior to the "login prompt boot", and, on balance, I suspect these may have been the ultimate cause. Speculation of course, though without evidence to the contrary, I typically assume issues are of my own creation rather than the fault of otherwise perfectly stable software and hardware. The original question about mdadm output was more a sanity check that the arrays were configured consistent with expectations. I'm thinking of setting both LOCKUP_DETECTOR and DETECT_HUNG_TASK in future kernel builds, hopefully these will provide additional information should something similar happen in the future. Are there any other recommended kernel settings I should implement? Thanks again, Bobby -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
