Logical volume management
Alexander Leidinger
Alexander at Leidinger.net
Sun Nov 20 04:59:30 PST 2005
On Sat, 19 Nov 2005 16:02:16 +1100
Peter Jeremy <PeterJeremy at optushome.com.au> wrote:
> The other disadvantages I see are:
> - All the cylinder groups headers are pre-allocated. AFAIK, UFS2 avoids
> pre-allocating the inodes but still reserves the space for them. A
> large virtual filesystem will have significant overheads even if it
> only has a small amount of real data.
> - UFS assumes that all the space is physically available and allocates
> blocks so as to (hopefully) maximize performance. This is likely to
> lead to significant fragmentation with lots of partially utilised
> data chunks.
I think those are the reasons why Sun decided to integrate the "new" VM
and the new FS code into one black box called ZFS (to prevent someone
from using a plain UFS with the new VM and then moan because of the
non-optimal performance).
Bye,
Alexander.
--
Speak softly and carry a cellular phone.
http://www.Leidinger.net Alexander @ Leidinger.net
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