> For me, agressive prefetch is most important in order to schedule > reads from enough disks in advance to produce a high data rate. This > is because I am using mirrors. When using raidz or raidz2 the > situation should be a bit different because raidz is striped. The > prefetch bug which is specifically fixed is when using thousands of > files in the 5MB-8MB range which is typical for film postproduction. > The bug is that prefetch becomes disabled if the file had been > accessed before but its data is no longer in cache.
I'm planning on using RAIDZ2 if it can keep up with my bandwidth requirements. So maybe ZFS could be an option after all? > That is not clear to me yet. With my setup, I can read up to > 550MB/second from a large file. That is likely the hardware limit for > me. But when reading one-at-a-time from individual 5 or 8MB files, > the data rate is much less (around 130MB/second). By MB do you mean mega*byte*? If so, 550 MB is more than enough for uncompressed 1080p. If you mean mega*bit*, then that's not enough. But as you said, you're using a mirrored setup, and RAID-Z should be faster. This might work for Final Cut editing using QuickTime files. But FX and color grading using TIFF frames at 130 MB/s would slow your setup to a crawl. Do you think RAID-Z would help here? Thanks! -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
