On 30 March 2014 20:11, Jimmy Kaplowitz <[email protected]> wrote:
> Heh, I didn't think a thread entitled "AWS summits" would be so GCE > focused, or otherwise something I should focus on given my employer. Well > done proving me wrong. :) > > Yeah we've noticed some timing issues around kpartx too; gcimagebundle > (one of the tools we install) has started to use the -s option to kpartx > and also calls sync after umount. Those make it more fully synchronous. > > I think we recently added some sleeps too, but I forget if the flakiness > which motivated that occurred on wheezy or not (we do support CentOS / RHEL > / SLES which all have older kernels & older util-linux-ng aside from > patches/bugfixes). > > Olivier/Anders - I agree, merging the code sooner rather than later makes > sense. > > - Jimmy > On Mar 30, 2014 10:58 AM, "Tomasz Rybak" <[email protected]> wrote: > >> Dnia 2014-03-25, wto o godzinie 19:50 +0100, Anders Ingemann pisze: >> [ cut ] >> >> > Alright. What gets me confused though, is that I thought kpartx -a was >> > blocking rather than asynchronous (which it would be if a sleep call >> > is really necessary). Aren't calls to the kernel that do things like >> > mapping devices synchronous? >> >> I'm wondering whether it is problem with kernel or with udev >> which has some delay when creating device files. >> Everything was OK when I was manually repeating steps from >> scripts (kpartx, mount, etc.) - but the same commands >> were failing when executed from the scripts. >> >> I hope to play with it on additional machines this week - and >> we'll see how it goes. >> >> -- >> Tomasz Rybak GPG/PGP key ID: 2AD5 9860 >> Fingerprint A481 824E 7DD3 9C0E C40A 488E C654 FB33 2AD5 9860 >> http://member.acm.org/~tomaszrybak >> >> > Yeah we've noticed some timing issues around kpartx too; gcimagebundle (one of the tools we install) has started to use the -s option to kpartx and also calls sync after umount. > Those make it more fully synchronous. Damn, you're right: "-s sync mode. Don't return until the partitions are created" How the hell is this not the default option?! With all other fs commands you turn stuff like this *on*. Like --lazy with mount.
