I have a pool with a single SLOG device rated at Y iops. If I add a second (non-mirrored) SLOG device also rated at Y iops will my zpool now theoretically be able to handle 2Y iops? Or close to that? Thanks, Ray
> From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss- > bounces at opensolaris.org] On Behalf Of Ray Van Dolson > > I have a pool with a single SLOG device rated at Y iops. > > If I add a second (non-mirrored) SLOG device also rated at Y iops will > my zpool now theoretically be able to handle 2Y iops? Or close to > that?Yes. But we''re specifically talking about sync mode writes. Not async, and not read. And we''re not comparing apples to oranges etc, not measuring an actual number of IOPS, because of aggregation etc. But I don''t think that''s what you were asking. I don''t think you are trying to quantify the number of IOPS. I think you''re trying to confirm the qualitative characteristic, "If I have N slogs, I will write N times faster than a single slog." And that''s a simple answer. Yes.
On Tue, Oct 12, 2010 at 08:49:00PM -0700, Edward Ned Harvey wrote:> > From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss- > > bounces at opensolaris.org] On Behalf Of Ray Van Dolson > > > > I have a pool with a single SLOG device rated at Y iops. > > > > If I add a second (non-mirrored) SLOG device also rated at Y iops will > > my zpool now theoretically be able to handle 2Y iops? Or close to > > that? > > Yes. > > But we''re specifically talking about sync mode writes. Not async, and not > read. And we''re not comparing apples to oranges etc, not measuring an > actual number of IOPS, because of aggregation etc. But I don''t think that''s > what you were asking. I don''t think you are trying to quantify the number > of IOPS. I think you''re trying to confirm the qualitative characteristic, > "If I have N slogs, I will write N times faster than a single slog." And > that''s a simple answer. > > Yes. >Thanks. :)