Date: Mon, 13 Oct 2014 14:25:19 -0700 From: Lyndon Nerenberg <lyndon@orthanc.ca> To: Don Lewis <truckman@FreeBSD.org> Cc: freebsd-stable@FreeBSD.org Subject: Re: getting to 4K disk blocks in ZFS Message-ID: <E44D9624-D8A2-4CA5-B399-3C1983904CA9@orthanc.ca> In-Reply-To: <201410132047.s9DKlGxD030176@gw.catspoiler.org> References: <201410132047.s9DKlGxD030176@gw.catspoiler.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--Apple-Mail=_F8830B7C-F8B5-4799-BA91-F14FEB3DD492 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii On Oct 13, 2014, at 1:47 PM, Don Lewis <truckman@FreeBSD.org> wrote: > Combine that with raidz and now the > overhead is about 40%. Ouch! But ~33 of that 40% is generic RAID overhead, and has nothing to do with = the 4K block size issue. (I.e., you would have 33% hit even if you were = running UFS on a three disk RAID5.) On any real-world system where you're running ZFS, it's unlikely the 4K = block overhead is really going to be an issue. And the underlying disk = hardware is moving to 4K physical sectors, anyway. Sooner or later = you're just going to have to suck it up. --lyndon --Apple-Mail=_F8830B7C-F8B5-4799-BA91-F14FEB3DD492 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- iQIcBAEBAgAGBQJUPEM/AAoJEG8PnXiV/JnU/fwP/i5a9ns87syp7G8aGMPVu7tk UMQilNakksxbIsVxmLk/qKgnktAaEX6e871KPSSAgB34EZkV5UCpdARMtCD1Vdmu iJVCdwqODtz2pgWYI7T1PYP2swnl2gpQvWt1SToMEITP0Tyqeqh184Cmj9fMoUI+ WwuIZ3emlF4VXBPCJxYDyR7BsbBEM8MMYzlwBxSGTTZzJoqoPwOMYrmx4fW3ALXe SnV7buUTSIMUYfIHfIlMDiOrfFS7/n8xy0cKFSyHCGW/uzTDVdfMEWzHZPc/ALQD 7+rQZRXTIHya/0xkksLnBTPZQ5o9/+PGZ5k0UIgGQCPFGXLSiRSHgsz/FGlg467i w+38g1933+iMTFoawmU4QV+YvrwWnddqcZbcqI6zM9kcCOy47LUJ7+oKildg421u AXOmVMEtJ6v27pK0xcBUqPGeP/GGzXvMZF4GV251iL7W7LcAqC8jLBVaRvT/uRYn U5h4IM4FDBQYsb3dW6N6mkjTXK3eo2hc7iwZnZCrA6qIxL5DqmbBxmrXC/wtuR/8 UFA7pS4qP+NKoTWXq7vxZhpm4KqZSBVCSoSQpNRUjhM/r++VUSRNsQYb01DSKj1F FOFCea+Opwgj1Na0/IWInecIeH9IcUQYyjD2y3l1aedhlvsmaFwkm1tF2J2FIu70 1jT9aCRZSkfcV9is5/nD =TiSk -----END PGP SIGNATURE----- --Apple-Mail=_F8830B7C-F8B5-4799-BA91-F14FEB3DD492--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?E44D9624-D8A2-4CA5-B399-3C1983904CA9>