Date: Sat, 20 Feb 2010 00:37:44 +0100 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Garrett Cooper <yanefbsd@gmail.com> Cc: freebsd-fs@freebsd.org Subject: Re: HAST (Highly Available Storage) now in HEAD. Message-ID: <20100219233744.GG1617@garage.freebsd.pl> In-Reply-To: <7d6fde3d1002191511h4caac149tf39dcc37cf750afe@mail.gmail.com> References: <20100219200725.GA1617@garage.freebsd.pl> <7d6fde3d1002191511h4caac149tf39dcc37cf750afe@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--VkqCAaSJIySsbD6j Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 19, 2010 at 03:11:44PM -0800, Garrett Cooper wrote: > Very cool stuff. How many nodes max are you targeting for this > service [...] Currently HAST is intended for use only with High Availability clusters, not for performance clusters and is limited to exactly two nodes - one primary node, which has access to shared storage and one secondary node, which just receives updates from primary. User's applications should only work on primary node. > [...] and what are some of the performance numbers for syncing > across the network (say with a 1GigE or 10GigE connection)? HAST should be able to saturate 1GigE link if you have fast enough storage. I've patches in the works to save data copying between userland and kernel. Currently, eg. write I/O request comes from the kernel, it is copied to hastd userland daemon, hastd copies it back to the kernel when writing to local component and then copies it again to the kernel when sending over network to secondary node. In other words a lot of copying. I prototyped a model where data is not copied at all between userland and kernel, but it needs a bit more work. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --VkqCAaSJIySsbD6j Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAkt/IMcACgkQForvXbEpPzTRagCdFSHqafi4fu9eBhaFrwXRcOmJ a38AoLdjFJ0iAs1IdobGLhJmsGFkvS+F =5QmY -----END PGP SIGNATURE----- --VkqCAaSJIySsbD6j--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20100219233744.GG1617>