That seems like a reasonable approach. Would be nice to work with packagers to verify that the packages are properly installing nbd. I'm pretty sure i used kpartx because i didn't know about the max_part parameter.
Vish On May 2, 2012, at 11:37 AM, Lee Schermerhorn wrote: > With diablo plus some of our own changes, we've discovered our compute > nodes in some of our test nova environments are littered with > orphaned /dev/mapper/nbd* links to /dev/dm-* devices that are holding > the respective nbd devices. Of course, this causes injection failure > for VMs that attempt to reuse those wedged nbd devices that appear > available by the method that nova uses to determine nbd device > availability. > > This could well be self-inflicted, and we haven't gotten down to the > root cause. However, in looking at it, we're wondering why the compute > manager uses kpartx, specifically atop nbd device. It does appear to be > rather fragile and nbd devices do support partitioned images if the > module is installed with max_part > 0, where zero is the unfortunate > default. > > We're thinking that maybe we can dispense with kpartx and, ensuring that > the nbd module is installed with max_part > 0 on our compute nodes, use > the resulting /dev/nbdXpY devices directly. But, before we charge off > down that path, we want to understand the rationale for using kpartx > atop nbd. We've searched the wiki and git logs and the wider 'net for > enlightenment. Finding none, we turn to the collective wisdom of the > Community. > > Is there some problem with qemu-nbd and partitioned images that argues > against this approach? Perhaps qemu-nbd doesn't recognize/support all > of the partition table types that kpartx does? Something more > insidious? > > Anyone know? > > Regards, > Lee Schermerhorn > > > > > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : openstack@lists.launchpad.net > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
