On 07/18/2013 08:21 PM, Steve Langasek wrote:
But unless you've only ever used Debian on systems with a flat partition:filesystem structure, with no network filesystem mounts, no LVM/RAID/LUKS, and no networks more complicated than a single interface, you've either been affected by these race conditions, or you've been relying on the chewing-gum-and-baling-wire workarounds that Debian has in place to paper over these races. The problems are pervasive and systemic, and have become progressively more severe over time as hardware becomes faster. An init system that has not *fundamentally* addressed this class of problem with its design is not bringing anything interesting to the table.
I fully agree with you here, Steve. NFS mounts (with or without autofs) don't cope very well with fast booting machines as well as machines with several (virtual or physical) interfaces. I don't know how often I ended up with a machine on the network where half of the NFS automounts weren't there until I restarted the autofs daemon simply because autofs was initialized prior the network was properly working. And, yes, the LSB init scripts contain the correct dependencies and yet it doesn't work properly. An init daemon which makes sure that a certain resource is properly configured or a daemon is really running, is essential nowadays to boot sophisticated systems reliably. I have also seen the need for resource management ala cgroups on our large compute clusters. When dozens of users are using a very large cluster simultaneously, you want to have the possibility to limit the resources per user such that a single user won't be able to bring down the whole cluster or have the OOM killer kick in. I have seen users bring down a central login node because they were smart enough to start a huge calculation on the login node instead of actually queuing their job onto the cluster itself.
The people who have dismissed boot speed as a matter for toy systems are being naive. It is not the number one priority for upstart or for anyone else; but downtime costs money, just as inefficient power control on systems costs money; and time spent booting is downtime. Time spent improving the boot speed for the millions of systems that run Debian is time well spent.
systemd (and upstart) actually show their fast booting in virtual machines which are very common nowadays on server farms. I have virtual machines running Debian unstable with systemd which boot in less than 4 seconds. Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaub...@debian.org `. `' Freie Universitaet Berlin - glaub...@physik.fu-berlin.de `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913 -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/51e83ba5.5070...@physik.fu-berlin.de
