Andrew Gabriel <[EMAIL PROTECTED]> wrote:
> That is exactly the issue. When the zfs recv data has been written, zfs
> recv starts reading the network again, but there's only a tiny amount of
> data buffered in the TCP/IP stack, so it has to wait for the network to
> heave more data across. In effect, it's a single buffered copy. The
> addition of a buffer program turns it into a double-buffered (or cyclic
> buffered) copy, with the disks running flat out continuously, and the
> network streaming data across continuously at the disk platter speed.
rmt and star increase the Socket read/write buffer size via
setsockopt(STDOUT_FILENO, SOL_SOCKET, SO_SNDBUF,
setsockopt(STDIN_FILENO, SOL_SOCKET, SO_RCVBUF,
when doing "remote tape access".
This has a notable effect on throughput.
Jörg
--
EMail:[EMAIL PROTECTED] (home) Jörg Schilling D-13353 Berlin
[EMAIL PROTECTED] (uni)
[EMAIL PROTECTED] (work) Blog: http://schily.blogspot.com/
URL: http://cdrecord.berlios.de/private/ ftp://ftp.berlios.de/pub/schily
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
