What it does is the userland hangs, but the kernel keeps running.
When the system is crashed, I can still ping it successfully, and I can still open sockets (like I can open a connection to a jails httpd or sshd, or the sshd of the underlying server itself) but nothing answers on the sockets - they just hang open. So everything stops running, but it is still "up" - still responds to pings...syslog stops logging though, cron stops running.... Two questions for you: 1) do you allow them write access to their /dev/mem, /dev/kmem, /dev/io ? 2) does this sound like what you see? Can you still ping the crashed server ? I'm mostly just curious if this kind of crash (userland hung but kernel running) is a possible outcome of someone in a jail fiddling with those /dev nodes, or if fiddling with dev/mem or /dev/kmem or io would just lock the machine up hard and completely. Terry? --PT On Fri, 21 Jun 2002, Nielsen wrote: > Yes I've had the same problem. One system runs just fine with it's jails, > and another crashes habitually. It has to do with a certain jail (and > services). Our system are set up to be able to move jails between them > (great for backups and near perfect uptime), and a certain set of jails > always hangs the system in this way. I'm trying to narrow it down. Do you > get a core dump or does it just hang? > > Nate > > ----- Original Message ----- > From: "Patrick Thomas" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, June 21, 2002 16:43 > Subject: (jail) problem and a (possible) solution ? > > > > > > A test server of mine running a number of jails keeps locking up - but the > > odd thing about the lockup is that the userland stops, but the kernel > > keeps running > > > > (sockets can be opened, but the servers never respond on them, the machine > > still responds to pings, but logs show that all real activity stops) > > > > I just noticed today that some jails still have writable /dev/mem and > > /dev/kmem and /dev/io nodes. I think it is plausable that some kind of > > fiddling (writing) to these nodes is causing this kind of lockup. > > > > ---- > > > > Is this assumption reasonable, or if some jail user fiddled with their > > /dev/mem or /dev/kmem or /dev/io node would it just totally crash out the > > machine and I _wouldn't_ still be able to ping the server after it crashes > > ? > > > > thanks, > > > > PT > > > > > > To Unsubscribe: send mail to [EMAIL PROTECTED] > > with "unsubscribe freebsd-hackers" in the body of the message > > > > To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
