I was debugging the traffic from one of my network devices that broadcasts each minute on multicast.
The following code was helpful to work through the output and why my python script wasn’t picking up the output any more.
tcpdump -nnXs 0 -i en0 udp port 22600 and dst 224.192.32.19
I was debugging some code/checking if a device was in fact broadcasting. This code listened and logged all outputs:
sudo tcpdump -n -c 100 multicast | perl -n -e 'chomp; m/> (\d+.\d+.\d+.\d+).(\d+)/; print "udp://$1:$2\n"' | sort | uniq
And to see the traffic:
sudo tcpdump ether multicast
I hadn’t noticed but my log directory was slowly growing. This is running on a digitalocean droplet.
Taken from: https://www.digitalocean.com/community/tutorials/how-to-use-journalctl-to-view-and-manipulate-systemd-logs
Deleting Old Logs
If you use the –vacuum-size option, you can shrink your journal by indicating a size. This will remove old entries until the total journal space taken up on disk is at the requested size:
sudo journalctl --vacuum-size=1G
Back to a healthier size.
I ran out of space on a Ubuntu VM.
1) Add more space via VMWare. Reboot VM.
2) ‘fdisk -l’ to show the partitions on the disk
3) ‘fdisk /dev/sda’ and then
Type p to print the partition table and press Enter
Type n to add a new partition
Type p again to make it a primary partition
Accept the defaults for cylinder start and finish
Type w to save these changes
REBOOT
4) ‘fdisk -l’ to show the partitions on the disk
5) Add the physical volume to the volume group.
In my example:
vgextend /dev/mapper/server–vg /dev/sda4
6) Extend the logical group by the amount of space added.
In my example:
lvextend -L+20G /dev/mapper/server–vg-root
7) Resize the file system to use it
resize2fs /dev/mapper/server–vg-root
That should make the new space usable. In my case it did anyway. Down from 99% full to 46%.
I run MRTG to monitor my internal network stats:
However, I had been manually editing the cfgmaker produced file to show interfaces (ports) that were ‘down’ at the point of running the config maker.
I migrated to a new switch so, decided to read the manual.
cfgmaker --show-op-down .........
Works a treat and now all interfaces are displayed.
I’ve been having issues with /etc/resolv.conf resetting after a reboot or periodically. I set static IPs on the NICs but this wasn’t enough.
To fix it I:
nano /etc/resolvconf/resolv.conf.d/base
And put the relevant settings, e.g.
nameserver 192.168.1.XXX
Then, regenerate the resolv.conf file
resolvconf -u
grep -Ri “text-to-find-here” /
i stands for upper/lower case
R stands for recursive.
try this
sync
echo b > /proc/sysrq-trigger
If like me, you keep getting stuck with ‘coldreboot’ and the GPU hanging, causing the rig to get stuck without going and turning the power off and on.
I use BAMT for my mining setup. I recently wanted to use these rigs for VertCoin. Here is how I managed it fairly easily:
cd /home/user
git clone https://github.com/Bufius/vertminer-gpu.git
cd vertminer-gpu
cp /opt/miners/cgminer/ADL_SDK/*.h /home/user/vertminer-gpu/ADL_SDK/
./autogen.sh
CFLAGS="-O2 -Wall -march=native" ./configure
make
make install
mv /opt/miners/cgminer /opt/miners/cgminer-current
mkdir /opt/miners/cgminer
cp -R /home/user/vertminer-gpu/* /opt/miners/cgminer/
ln -s /opt/miners/cgminer/vertminer /opt/miners/cgminer/cgminer
cp /etc/bamt/cgminer.conf /etc/bamt/cgminer.conf.SCRYPT
export DISPLAY=:0
export GPU_USE_SYNC_OBJECTS=1
export GPU_MAX_ALLOC_PERCENT=100
Now write to /etc/bamt/cgminer.conf and put in your correct settings. On my R9 280X I use the following to connect to my p2pool node:
{
"pools" : [
{
"url" : "stratum+tcp://vertcoinpool.com:9171",
"user" : "Vwtr2b2RxYxu7gY429H7nbry95nWzgC245+0.001/0.0001",
"pass" : "x"
},
{
"url" : "stratum+tcp://europe.vertcoinpool.com:9171",
"user" : "Vwtr2b2RxYxu7gY429H7nbry95nWzgC245+0.001/0.0001",
"pass" : "x"
}
]
,
"intensity" : "13",
"vectors" : "1",
"worksize" : "256",
"lookup-gap" : "2",
"shaders" : "0",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "2",
"gpu-engine" : "1020",
"gpu-memclock" : "1500",
"gpu-powertune" : "-20",
"thread-concurrency" : "8191",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "60",
"shares" : "0",
"kernel-path" : "/usr/local/bin"
}
Now to get started.
service mine restart
And use
screen -r
to see how you’re doing.
You can use my p2pool node at www.vertcoinpool.com for mining VertCoin (VTC) on the p2pool network.
sudo su to the UID screen belongs to.
screen -ls – view the running SCREEN sessions
screen -r xxxx – for the session you wish to reconnect to, e.g. 3245.minime