I swear ethtool used to be able to give status on a link without having to plumb the interface. This is just bogus waste of time.
What I need ASAP in my sysadmin world is a very small network tool, installed by default, that will quickly check link light, media options, and if connected, what networks it's connected too. I can't be the only one who's sturggled with miscabled systems or the enumeration of ports. Why doesn't this exist!?
No, I don't mean post it notes. Sometimes it's handy to take notes cooleseced elsewhere and put them on the screen you're working on. Here's my lame way to do that.
$ echo << EOF
> sdf
> sdf
>
You exit out with a ^D (or ctrl-d for those in the windows world)
I can't believe how much time I wasted today trying to remember the escape sequence for iLom! Here's some notes to avoid some pain.
First off, the escape sequence is not `#.` or `Escape-(`, it is `Esc (`. That means, hit the esc key, let go, then hit the left parentheses, and let go. I had to seem condescending, but there's lots of ways to screw this up, and I explored many of them. The escape sequence is what you enter to get out of using the console. To get into the console, type in `start /SP/console`. Yes, caps matter - it's Sun (now Oralce) and therefore unixy.
This one really threw me off. I buld a rhel-6.1 test box, and I couldn't get in using the root ssh key I loaded into ssh-agent. The `ssh-copy-id` worked fine. However, I was getting prompted for the account password (not my key's password). Here's what I saw and here's how to get around it.
Did you know there's a difference between GMT and UTC? I didn't. I haven't found it stated succinctly on the web, but it has to do with leap seconds and the increase of them due to tidal deceleration. Tidal deceleration is like how it is difficult to move a big tub of water around due to the inertia being in liquid form absorbing energy. The point is, I needed to change the timezone on some servers and here are my notes.
rhel6 uses postfix by default (very nice). I've been used to changing the DS line in /etc/mail/sendmail.cf Now, what you do is: postconf -e "relayhost = [myrelay.fqdn]"
The answer is technically /bin/ps -ef. But what you really want is /bin/netstat -plunt. Netstat prints network connections, routing tables, interface statistics, masquerade connections, and multicast memberships. The switches that make this possible and handy are:
First the cheet sheet to using native FC tools and drivers (tested on rhel5): pWWN = cat /sys/class/fc_host/host[0-9]/port_name
WWN = cat /sys/class/fc_host/host[0-9]/node_name
online? = cat /sys/class/fc_host/host[0-9]/port_state
Speed = cat /sys/class/fc_host/host[0-9]/speed
HBA overview = cat /sys/class/fc_host/host[0-9]/symbolic_name
/sys/class/fc_host/host[0-9]/device/scsi_host\:host[0-9] is same as /sys/class/scsi_host/host[0-9] HBA make = cat /sys/class/scsi_host/host[0-9]/model_desc
In case you didn't think it through (like I didn't), you can't vMotion guests from one type of CPU to another. And when I say type, I don't just mean AMD to Intel, I mean different models and generations. For example, you can't go from Family 6, Model 46 (2Eh) = Nehalem-EX to Family 6, Model 47 (2Fh) = Westmere-EX/E7... at least not live. It makes sense. However, there is one exception: EVC.
