On Fri, Jan 30, 2015 at 09:04:00AM +0100, Markus Pargmann wrote: > Hi, > > On Fri, Jan 30, 2015 at 12:42:54AM +0100, Wouter Verhelst wrote: > > Not that I'm opposed to this, but you do realize that doing nbd-client > > from initramfs or similar is possible, right? Most initramfs > > implementations these days support it. > > Yes, that was the first idea how to implement a complete netboot for an > embedded ARM device. However, an initramfs is at least around 1MB in > size which has to be loaded using tftp. As the essential nbd-client > connection setup and negotiation is quite small I decided to go with > nbd-root support. > > Also it is quite useful to have nbd-root support much like nfsroot > directly built-in for debugging purposes. It has the big advantage of > booting/testing read-only filesystem images for embedded systems without > the need for an initramfs.
Fair enough, just thought I'd point it out. When looking at your patch set, two things pop out which you should probably look at: - What will happen if someone boots with root-on-NBD in your scheme and later does a pivot_root() followed by an NBD_DISCONNECT ioctl on the device? - When a connection is started by nbd-client, the kernel creates a "pid" file in sysfs, which contains the PID of the client and which the client (when called with -c, or in other cases) uses to verify whether a device is connected. At first glance, your patch does not do this, which could cause confusion. I must admit I haven't checked your patch very well (my kernel fu isn't that advanced) so I might have missed something, but I'd rather point it out now than have to fix the pieces afterwards ;-) -- It is easy to love a country that is famous for chocolate and beer -- Barack Obama, speaking in Brussels, Belgium, 2014-03-26 ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Nbd-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/nbd-general
