esxi enable snmp

How to enable snmapd on your vmware esxi server

replace with your IP-range
esxcli system snmp set --communities public
esxcli system snmp set --enable true
esxcli network firewall ruleset set --ruleset-id snmp --allowed-all true
esxcli network firewall ruleset set --ruleset-id snmp --enabled true
esxcli system snmp set --syslocation "My Location"
esxcli system snmp set --targets=

Now you can start the service from the UI

failed Import ZFS pools by cache file

A single disk zpool “test” crashed on my server (the disk died). It was just for testing, so nothing dramatic. However, when I rebooted the server I got the error message “failed Import ZFS pools by cache file”.  A zpool destroy -f did not solve the problem. zpool status still showed the “test” pool. The other pool tank was still working.

What did help was

# disable the cache file for the existing pool(s)
zpool set cachefile=none tank
# delete the old pool file
rm -rf /etc/zfs/zpool.cache
# recreate if
touch /etc/zfs/zpool.cache
# re-enable the cache
zpool set cachefile=/etc/zfs/zpool.cache tank

Well, the cache file should be automatically updated when your pool configuration is changed, but with the crashed pool it did not.

resize2fs new size too large to be expressed in 32 bits

After virtualizing a real computer with an old Linux I wanted to increase the partition size of the data drive. But I got this warning: resize2fs new size too large to be expressed in 32 bits

How to solve this? I started the VM with gparted-live.iso

# check file system
e2fsck -f /dev/sdb1
# auf 64 bit ändern
resize2fs -b /dev/sdb1
# increase partition .... wait :D / optional coffee
resize2fs -p /dev/sdb1
# check file system
e2fsck -f /dev/sdb1

Done :)

ban ’em all

Ban all the attackers. Easier said than done. A website is constantly under attack as the whole server. One day I decided it was too difficult to maintain every single server and ban those attackers. Blocking IPs on the website level is too late. Also, it consumes a lot of resources. So I went for iptables. You can find it on github/JBlond/ban_em_all

DROP vs REJECT. Well, DROP is a bad option for debugging. Also, it is not the default behavior of the OS itself. Nothing is listing on a port? The OS sends a reject. Sadly I haven’t found a way to use REJECT when it comes to IPs. Using DROP on the other hand the automatic server/website scanners assume a firewall and it is more likely to continue the scan.

Add real emojis and icons to mintty bash on windows

Installing git for windows isn’t hard anymore. I recommend installing “Git for Windows SDK” so you can install extra packages via Pacman. I like fish shell and tmux, and those aren’t included in the default installer. Either way, you can run bash and or fish on windows. The emojis and icons however don’t look very pretty, more like DOS-style.

Open a shell and cd to

C:\Program Files\Git\usr\share\mintty\emojis or C:\git-sdk-64\usr\share\mintty\emojis depending what installation you chose.

cd C:\git-sdk-64\usr\share\mintty\
mkdir emojis
cd emojis
curl -LO
getemoji -d
getemoji .

In mintty:
Options -> Text -> Emojis -> style: google
Options -> Text -> Character set -> UTF-8

jQuery bind after ajax load

Sometimes it is needed to add a jQuery event listener to an element that isn’t present in the DOM at the creation of the page but created during runtime or the result of an ajax call.

What doesn’t work is

jQuery(document).ready(function () {
        click: function  (event){
            console.log('I work only with existing elements');

However, there is a way to achieve that.

jQuery(document).ready(function () {
    jQuery(document).on('click', '.selector', function (event){
        console.log('I work with a dynamically created elements');

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