Dne 10.9.2010 17:53, yue napsal(a): > i want to know lvm2 on source-code level. > and kernel device-mapper?? > just analysis source code is hard, can you give me some function-call stream. > and whole blueprint. If you really want to know 'in-depth' detail - I may suggest to use tools like kcachegrind to get flow-control. It's in fact not so easy to describe lvm2 functionality in few lines and it's also 'moving' target as some call flow changes over the time. Very slight overview might look like this: - read config - scan available block devices according config (changes quite a lot with udev integration and cache usage) - create internal structures and do some action according to given command - some of commands are changing dm table - so internal dm tree structure is generated - this abstraction is hidden in libdm - activation/deactivation is executed - note - as lvm2 supports clusters - this is somewhat more complex and unless you plan to have a very deep look inside you probably don't want to know all the magic behind - lots of limits apply - very tight memory rules needs to be preserved to avoid deadlocks... If you plan to add new 'target' - you may look into lib/striped subdir - there is very some simple example. Some sort of 'virtual' methods calls are used - unfortunately this call flow is far from complete so target usually needs few quirks here and there over the whole code base for now and usually knows a long depth knowledge of this process - far from perfect, but that's current status... Zdenek
_______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
