[linux-lvm] Can we make char files not blocked for the volumes
Stephen C. Tweedie
sct at redhat.com
Tue Feb 22 17:50:42 UTC 2000
On Mon, 21 Feb 2000 16:45:06 -0600, Chris Anderson <chris at alwan.com>
> It is odd how it is used. I had to hack it into 2.2.14, but go it working.
> I think the "raw" command is odd, also it needs to be run every time you
Indeed --- the raw interfaces need to be bound to specific devices just
as eth* network interface names need to be bound to addresses.
> Also who is the owner of this code. How does it find its way into
> the standard 2.3 and lvm has not yet? That is odd too.
lvm just took a little longer --- they are both in 2.3 now.
> My test with Informix IDS 7.3 for linux showed that the raw io is twice as
> slow. A 17 mins load under block device using lvm but took 31mins for the
> raw linked version. I will be testing the Informix 9.2 version
Raw IO does not do any caching in the O/S. Specifically, it doesn't
perform any readahead or writebehind. If the application was using
that implicit caching then raw IO will necessarily be slower.
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