Hi list, I''m thinking about to put the MS Exchange storage on a zfs volume via iscsi... I guess that''s not a problem, but the more interesting question is if it''s possible to get more performance using the l2arc function with a FusionIO Flash card... I understood the idea of the l2arc cache but I''m unsure how it works when sharing the pool over iscsi. Is the l2arc based on files or blocks? regards, Tobi
Hi, I''m pretty sure it will work. You should be able to easiyl test it - create an L2ARC on some device or a file and see if it is being used. -- Robert Milkowski http://milek.blogspot.com On Fri, 5 Jun 2009, Tobias Exner wrote:> Hi list, > > I''m thinking about to put the MS Exchange storage on a zfs volume via > iscsi... > I guess that''s not a problem, but the more interesting question is if it''s > possible to get more performance using the l2arc function with a FusionIO > Flash card... > > > I understood the idea of the l2arc cache but I''m unsure how it works when > sharing the pool over iscsi. Is the l2arc based on files or blocks? >
Tobias Exner wrote:> Hi list, > > I''m thinking about to put the MS Exchange storage on a zfs volume via > iscsi... > I guess that''s not a problem, but the more interesting question is if > it''s possible to get more performance using the l2arc function with a > FusionIO Flash card...In general, yes. But remember that l2arc stores data for reads only. It begins to fill when you run out of main memory. If you are currently running well within the bounds of main memory, then an l2arc won''t help. I would presume that more main memory would be more cost effective than a Fusion IO card on a cost/bit basis, if the machine has room for growth. Use arcstat to view arc usage.> I understood the idea of the l2arc cache but I''m unsure how it works > when sharing the pool over iscsi. Is the l2arc based on files or blocks?blocks. -- richard