[responding to myself, considering the audience] On Nov 3, 2014, at 11:30 AM, Richard Elling <[email protected]> wrote:
> > On Nov 2, 2014, at 6:24 PM, Rune Tipsmark <[email protected]> wrote: > >> Looking a bit more at these numbers, am I seeing twice the actual rate due >> to mirroring? > > You need to know what you are measuring. iostat and zpool iostat measure the > I/O from > the pool to the disk. This is often very different than an application to the > file system (pool). > In practice, it is often so different that it is impractical to correlate the > two. > >> How does compression affect the numbers? >> >> Say I have 1 vdev mirrored and I see the pool writing 100 MB/sec, its what? >> 50 MB each disk? But from the client side only 50 MB/sec total? What if I >> compress it at the same time at say 1.50 ratio, will the pool show 100 >> MB/sec and the client write 75 MB/sec actual? > > Measure both and compare. Usually we measure application side bandwidth using > a tool > such as fsstat. actually, we measure it using some sort of data collector that stores data for long-term analysis and includes handy graphing features (cue Circonus) -- richard _______________________________________________ OmniOS-discuss mailing list [email protected] http://lists.omniti.com/mailman/listinfo/omnios-discuss
