[issue1116] HAMMER:file read speed

[Matthew Dillon]

:ftp> put src.tar.gz
:local: src.tar.gz remote: src.tar.gz
:227 Entering Passive Mode (10,66,23,79,12,151)
:150 Opening BINARY mode data connection for src.tar.gz.
:100% |****************************************| 94806 KiB   11.21
:MiB/s    00:00 ETA
:226 Transfer complete.
:
:ftp> get src.tar.gz
:local: src.tar.gz remote: src.tar.gz
:227 Entering Passive Mode (10,66,23,79,12,154)
:150 Opening BINARY mode data connection for src.tar.gz (97081686 Bytes).
:100% |****************************************| 94806 KiB    4.11
:MiB/s    00:00 ETA
:226 Transfer complete.
:97081686 bytes received in 00:22 (4.11 MiB/s)
:
:Can I say that the hammer fs read speed is normal,but write speed is abnormal?

    This can't have anything to do with HAMMER at all.  A 97 MB file will
    fit completely in the buffer cache, reading or writing.

    This has to do with some VMWare muff up, probably related to either
    the network driver or the disk driver.

    Try posting the FreeBSD7 dmesg output too, maybe that will give us 
    a hint.

    As far as fully cached reads with dd go... that's probably a pipe
    or bcopy optimization issue.  But, again, all bets are off under VMWare.

						-Matt