block allocators and LVMs

From: christophe varoqui (christophe.varoqui@free.fr)
Date: Thu Oct 17 2002 - 15:30:05 EST


hello,

reading the recent threads about FS block allocator algorithms and about
possible integration of a new volume management framework, I wondered if
the role of intelligent block allocators and/or online FS defragmentation
could be replaced by a block remapper in the LVM subsystem.

On one hand, online defrag seems hard to achieve (Tru64 advfs still can't
get it right after 4 years) and intelligently allocating blocks can be
costly (not to say it could be useless on a heavily fragmented logical
volume) ... on the other hand, the pvmove envisionned by M. Thornber seems
quite able to handle the extend remapping.

The block device layer is pretty well positioned to know about disk head
seeks and could do IO accounting per extend. These information seems
sufficient to efficiently order extends.

Am I completely out of my mind ?
Evidently, I would be very proud if not but I can handle responses like
"crap. just stop thinking man"

.
cvaroqui
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Oct 23 2002 - 22:00:36 EST