This is a seriously beefed up chroot kind of thing. The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.
For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact: "real virtual servers".
Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.
Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.
It generally does what one would expect, but setting up a jail
still takes a little knowledge.
A few notes:
I have no scripts for setting up a jail, don't ask me for them.
The IP number should be an alias on one of the interfaces.
mount a /proc in each jail, it will make ps more useable.
/proc/<pid>/status tells the hostname of the prison for
jailed processes.
Quotas are only sensible if you have a mountpoint per prison.
There are no privisions for stopping resource-hogging.
Some "#ifdef INET" and similar may be missing (send patches!)
If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!
Tools, comments, patches & documentation most welcome.
Have fun...
Sponsored by: http://www.rndassociates.com/
Run for almost a year by: http://www.servetheweb.com/
transceiver. Note in the manual page that autoselection doesn't
work on the 82c168 because the built-in NWAY support is horribly
broken. Manual mode selection works fine, but autoneg is broken for
everything except maybe 10Mbps half-duplex. There's no simple way
to fix this at the moment, so I have to settle for documenting the
bug for now. Fortunately, there aren't anywhere near as many 82c168
boards around as there are 82c169s.
I changed to "Christopher G. Demetriou" since the page appears to be a
revision of lkm(4).
PR: docs/8611
Submitted by: Rajesh Vaidheeswarran <rv@fore.com>
Networks Tigon 1 and Tigon 2 chipsets. There are a _lot_ of OEM'ed
gigabit ethernet adapters out there which use the Alteon chipset so
this driver covers a fair amount of hardware. I know that it works with
the Alteon AceNIC, 3Com 3c985 and Netgear GA620, however it should also
work with the DEC/Compaq EtherWORKS 1000, Silicon Graphics Gigabit
ethernet board, NEC Gigabit Ethernet board and maybe even the IBM and
and Sun boards. The Netgear board is the cheapest (~$350US) but still
yields fairly good performance.
Support is provided for jumbo frames with all adapters (just set the
MTU to something larger than 1500 bytes), as well as hardware multicast
filtering and vlan tagging (in conjunction with the vlan support in
-current, which I should merge into -stable soon). There are some hooks
for checksum offload support, but they're turned off for now since
FreeBSD doesn't have an officially sanctioned way to support checksum
offloading (yet).
I have not added the 'device ti0' entry to GENERIC since the driver
with all the firmware compiled in is quite large, and it doesn't really
fit into the category of generic hardware.
kernel and userland modules.
Describe the superdevice method of ensuring that people at least
recognize the problem if they run into a debug synchronization problem.
