My config file of afserver contains the following line.
This lets me check the history of the activities of
at the status file, I noticed an interesting thing last
I have two kinds of machines: slow machines with slow
(10Mbit/s) and fast machines with fast ethernet cards
backup server is a 100MHz Pentium box with a fast
ethernet card and
puts the backup data on tapes using Exabyte 8505XL. The
compression of afclient on each machine is turned off.
Because slow machines cannot deliver the backup data
fast enough to
make the tape unit run in the streaming mode, I am
using a large disk
buffer by putting the following line in the config file
Tape-Buffer: 35000000 90 0 %V/tapebuffer
This let the server accumulate the data from slow
machines a few
minutes and dump the data on the tape unit at once.
writing speed recorded in the status file is quite
good, ranging from
600KB/s to 900KB/s. On the other hand, the first
machines that must be
keeping the disk buffer full shows slower writing
speeds ranging from
400KB/s to 700KB/s (this throughput does not seem to be
the size of the disk buffer). This is interesting,
isn't it? My guess
is that afserver is quite busy saying "Don't send data"
clients, the buffer being always almost full.
I am wondering if it isn't possible to have the
afserver to tell
afclients to slow down, when the afserver gets too fast
data. Or alternatively, isn't it possible to make
afclient smart so
that it automatically slows down when the server
rejects data transfer
too often. In either way, afbackup may be able to gain