My manager reminds me that "in the old Sun days", the ssh server came
up
first, *before* the fsck on boot, so that if there was a problem, and fsck
was waiting for an answer, you could remotely ssh in, kill it, restart it,
and answer (or give it the right flags).
Does anyone know if it's possible to have that happen with CentOS? It
would be nice to have it boot that way, so that if you checked, and
figured it should have been up already, you could handle the problem
without coming in....
mark
On Wed, Apr 27, 2011 at 4:14 PM, <m.roth at 5-cent.us> wrote:> My manager reminds me that "in the old Sun days", the ssh server came up > first, *before* the fsck on boot, so that if there was a problem, and fsck > was waiting for an answer, you could remotely ssh in, kill it, restart it, > and answer (or give it the right flags). > > Does anyone know if it's possible to have that happen with CentOS? It > would be nice to have it boot that way, so that if you checked, and > figured it should have been up already, you could handle the problem > without coming in.... > > ? ? ? ?markI think having a decent remote console is the solution to that. DRAC, KVMoIP, Serial console, etc... I'm not sure how it could be considered safe to start services like sshd before the filesystem has been checked. // Brian Mathis
On 04/27/11 1:14 PM, m.roth at 5-cent.us wrote:> My manager reminds me that "in the old Sun days", the ssh server came up > first, *before* the fsck on boot, so that if there was a problem, and fsck > was waiting for an answer, you could remotely ssh in, kill it, restart it, > and answer (or give it the right flags).not on any Sun I've ever seen. fsck happens before TCP or much of anything else maybe he's confusing the serial consoles of the Sun's, which were usually attached to Console servers that you could ssh into ?
On Wed, Apr 27, 2011 at 04:14:48PM -0400, m.roth at 5-cent.us wrote:> My manager reminds me that "in the old Sun days", the ssh server came up > first, *before* the fsck on boot, so that if there was a problem, and fsckDefine "old Sun". SunOS 3 and 4 never had ssh. Solaris 2.x, Solaris 7, Solaris 8 never came with ssh out of box. Solaris 9 was the first version to come with (a broken) SSH as part of the standard build.> was waiting for an answer, you could remotely ssh in, kill it, restart it, > and answer (or give it the right flags).No. You could do it on the console (as others have said) and so with a serial console connected to a terminal server, or with later-day LOM devices, you could get to the console "out of band". Sun, in fact, were the poster boys for needing to fsck because they threw a lot of stuff onto /usr and had /usr as a separate partition. And many many of the shared libraries were in /usr/lib, so you could only run statically linked programs (normally in /sbin) before filesystems were mounted. SunOS 4 didn't even have "cat" available, so the startup scripts had a shcat() function which used shell builtins to emulate it. -- rgds Stephen
m.roth at 5-cent.us <m.roth at 5-cent.us> wrote:> My manager reminds me that "in the old Sun days", the ssh server came up > first, *before* the fsck on bootAs others have indicated, but not in so many words, your manager is out to lunch in this case: ssh, once it was introduced, was started at run level 3 (or the equivalent, for SunOS 4, which wasn't SYSV). On old Sun hardware, you could connect to the serial port to get console. (You could also have a graphical console if you had the add-in video cards, but people rarely used those for anything but workstations.) If your serial console was on a console server or serial aggregator (like a modem server in reverse), then you could telnet into it to get console on the Sun box. Later, the serial console was augmented by the ALOM (which predates the DRAC for Dells). Originally you could only telnet into it (using a separate management ethernet connection) which means you should have your management interface on a separate admin net. Between 5 and 10 years ago, Sun got around to introducing SSH to the ALOM. At *that* point, you could ssh into a Sun to get console. Everything is relative, but I wouldn't refer to that as "the old Sun days", unless you're meaning "before Oracle". As I've mentioned on other threads, if you need this kind of functionality for an x86 box that doesn't have its own ALOM/DRAC/iLO (all manufacturer names for similar functions), I'd suggest the AdderLink iPEPS (network only) or iPEPS/DA (network + local kybd/monitor/mouse). It uses encrypted VNC instead of SSH, and can be teamed with an electronic KVM switch to allow you to use it with multiple machines. Devin -- I don't suffer from insanity. I enjoy every minute of it.