On 21/12/2010 21:53, Jeff Bacon wrote:
So, to Phil's email - read()/write() on a ZFS-backed vnode somehow
completely bypass the page cache and depend only on the ARC? How the
heck does that happen - I thought all files were represented as vm
objects?
For most other filesystems (and oversimplify
> Another alternative to try would be setting primarycache=metadata on
the
> ZFS dataset that contains the mmap files. That way you are only
turning
> of the ZFS ARC cache of the file content for that one dataset rather
> than clamping the ARC.
Yeah, you'd think that would be the right thing to d
On Tue, Dec 21, 2010 at 7:58 AM, Jeff Bacon wrote:
> One thing I've been confused about for a long time is the relationship
> between ZFS, the ARC, and the page cache.
>
> We have an application that's a quasi-database. It reads files by
> mmap()ing them. (writes are done via write()). We're talki
On 21/12/2010 14:25, Phil Harman wrote:
Hi Jeff,
ZFS support for mmap() was something of an afterthought. The current
Solaris virtual memory infrastructure didn't have the features or
performance required, which is why ZFS ended up with the ARC.
Yes, you've got it. When we mmap() a ZFS file, th
Hi Jeff,
ZFS support for mmap() was something of an afterthought. The current
Solaris virtual memory infrastructure didn't have the features or
performance required, which is why ZFS ended up with the ARC.
Yes, you've got it. When we mmap() a ZFS file, there are two main caches
involved: the
One thing I've been confused about for a long time is the relationship
between ZFS, the ARC, and the page cache.
We have an application that's a quasi-database. It reads files by
mmap()ing them. (writes are done via write()). We're talking 100TB of
data in files that are 100k->50G in size (the fi
