Carson Gaspar <[EMAIL PROTECTED]> writes: > Joerg Schilling wrote: >> Carson Gaspar<[EMAIL PROTECTED]> wrote: >> >>> Louwtjie Burger wrote: >>>> Dumping a large file from memory using tar to LTO yields 44 MB/s ... I >>>> suspect the CPU cannot push more since it's a single thread doing all the >>>> work. >>>> >>>> Dumping oracle db files from filesystem yields ~ 25 MB/s. The interesting >>>> bit (apart from it being a rather slow speed) is the fact that the speed >>>> fluctuates from the disk area.. but stays constant to the tape. I see up >>>> to 50-60 MB/s spikes over 5 seconds, while the tape continues to push it's >>>> steady 25 MB/s. >> ... >>> Does your tape drive compress (most do)? If so, you may be seeing >>> compressible vs. uncompressible data effects. >> >> HW Compression in the tape drive usually increases the speed of the drive. > > Yes. Which is exactly what I was saying. The tar data might be more > compressible than the DB, thus be faster. Shall I draw you a picture, or > are you too busy shilling for star at every available opportunity?
Sheesh, calm down, man. Boyd _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
