[ Thanks to Ray Yeargin
for this link. ]
“IBM recently announced plans to release a Logical Volume
Management System [LVMS] to the Linux community. While this is
surely good news, and IBM is shaping up to be a major supporter of
free software in general and Linux in particular, I am not
convinced that IBM’s LVMS will be an important addition to
Linux.”
“…the second problem is the important one — and it arises
from what may be the most appealing feature of this technology; the
ability to resize a filesystem while it’s mounted and in use.
… Using this feature, however, creates the following problems.
The filesystems themselves become fragmented across a single disk
as they are extended. Further, filesystems grow across multiple
disks in an unplanned way. These effects result in higher seek
times and, therefore, slower access to data even when only a single
file is read. Worse, they limit your ability to physically isolate
related files from each other so that reading a database index
might interfere with reading the very database file the index
points to.”
“LVMS is a complex piece of software doing a very sensitive job.
Those who actually need it will be few and they will require it to
be solid and proven. With several competing alternatives pulling
away would-be users, the adopters of LVMS will be fewer still.
Without a big base of users — and barring a significant effort on
the part of IBM — will LVMS ever get the extensive development and
testing it must have to become properly proven?”