Backtrack:  
 
showing posts of September 2019
 
by lunarg on September 26th 2019, at 12:11
Check_MK, standalone or as part of OMD (The Open Monitoring Distribution), has built-in support for monitoring AeroHive wireless infrastructure through a Hive Manager. It uses the on-premise Hive Manager in order to collect information from devices registered to the Hive Manager.

Note for HMOL users
Because the agent uses the Hive Manager API, HMOL environments are not supported, as they do not allow the HM API to be enabled.

By default, HM API is turned off. Log on to the Hive Manager using an admin account. Go to:

Home → Administration → HiveManager Settings

Scroll down to API Authorization Settings, then click Settings.

Check Enable API Access, and type in a username, and t  ...
by lunarg on September 24th 2019, at 16:37

You can use Powershell to get the block size of a Windows NTFS volume:

On newer systems:

Get-CimInstance -ClassName Win32_Volume | Select DriveLetter,Label, BlockSize | FT -AutoSize

On older systems, the Get-CimInstance may not be available, in which case you can use the (deprecated) Get-WmiObject:

Get-WmiObject -Class Win32_Volume | Select DriveLetter,Label, BlockSize | FT -AutoSize
by lunarg on September 18th 2019, at 12:02
When adding a new disk to a live system (e.g. a linux VM), the new disk may not always show up. Additionally, when resizing a disk through the hypervisor, the VM may not always immediately have the new size available for use. Luckily, you can trigger a rescan of the SCSI bus through the sysfs system.

For this to work, you'll need to have shell and root access to the server/VM.

Modern linux kernels automatically detect the addition of a disk, but in case it doesn't, you can trigger a rescan of a specific (virtual) SCSI controller:

echo "- - -" > /sys/class/scsi_host/hostX/scan

Replace hostX with the number of the SCSI controller, where host0 is the first, host1 is the second, et  ...
by lunarg on September 13th 2019, at 10:55
To quickly block traffic from/to a specific IPv4 address using iptables, you can use the commands below.

Warning!
Do not use these commands when you are already running an iptables-based firewall as this may result in unexpected results.

Block incoming traffic from a specific IP:

iptables -A INPUT -s 1.2.3.4 -j DROP

Block outgoing traffic (i.e. traffic initiated from the host itself) to a specific IP:

iptables -A OUTPUT -d 1.2.3.4 -j DROP

To block outgoing traffic to a specific port and protocol, you can also do something like this (the example below blocks DNS and HTTP):

/sbin/iptables -A OUTPUT -p tcp --dport 80 -d 1.2.3.4 -j DROP/sbin/iptables -A OUTPUT -p udp --dport 53 -d 1.2.3.4  ...
by lunarg on September 9th 2019, at 16:54
On VCSA, the database is stored on a separate disk. It could happen that this disk runs out of room, causing Vcenter to no longer function properly. One way to resolve this is by running database clean up as mentioned in KB 2110031. However, if this is not possible, or you don't want to clear out the data, you can also resize the disk.

For this to work, you'll need root access and access to the bash-shell, either on the console or through SSH.

Before resizing, identify the physical disk to be resized. For VCSA 6.5 and 6.7, this should normally be Disk 8 (device node in linux = /dev/sdh), but your setup may vary, so it's best to double-check this.

In VCSA 6.5 and 6.7, the database is locat  ...
by lunarg on September 9th 2019, at 12:45
Handling snapshots (creating, deleting, restoring) is rather intuitive when you already have some experience with PowerCLI. As a reference, here are some one-liners. As always with Powershell, there's more than one way to achieve a goal... The examples used here assume a VM named "SRV01". Adjust as needed.

Create a snapshot:

Get-VM SRV01 | New-Snapshot -Name "My snapshot"

Remove all snapshots (disabling confirmation request in the process):

Get-VM SRV01 | Get-Snapshot | Remove-Snapshot -Confirm:$false

To handle a specific snapshot, you could do something like this:

$vm = Get-VM SRV01$snap = Get-Snapshot -VM $vm -Name "My snapshot"# do something with the sn  ...
by lunarg on September 5th 2019, at 16:43
For users which really want to prevent Windows 10 from automatically installing updates, here are some methods to disable automatic updates. Depending on which method you use, you will still be able to manually check and install updates, or not be able to install updates at all...

Note that the methods leverage group policies, which is not supported on Windows 10 "Home/Essential" editions. A minimum of Windows 10 Pro or better is needed.

Caution
It is generally not recommended to disable automatic updates. Doing so (and not subsequently regularly installing the updates yourself) increases the risk of data loss and/or stealing due to potentional vulnerabilities in Windows 10.

The  ...
 
showing posts of September 2019
 
 
« November 2019»
SunMonTueWedThuFriSat
     12
3456789
10111213141516
17181920212223
24252627282930
 
Links
 
Quote
« I needed a password with eight characters so I picked Snow White and the Seven Dwarves. »