In order to TRIM a SSD device that is plugged in through USB, the attached perl script can be used. This script was created after reading the following post:
http://askubuntu.com/questions/262154/trim-and-ssd-with-usb-3-0-enclosu…

To view all host file entries for all machines (assuming the machine you are on has the AD powershell modules, and can reach all machines):

foreach ($comp in Get-ADComputer -Filter * -Properties Description | Where-Object { $_.Description.Length -eq 0 -or $_.Description -ne "Failover cluster virtual network name account" }) 
{ 
	$hostfile= "\\"+ $comp.name +"\c$\windows\system32\drivers\etc\hosts"; 
	$comp.name; 
	$data=Get-Content $hostfile;
	foreach($line in $data) {
		if($line.Length -eq 0 -or $line.StartsWith("#")) {
			continue;
		}
		$line
	}
}

We have some iSCSI setups using a linux pacemaker cluster, and I have always had issues with adding more resources. The setup is as follows:

• IP Primitive - One for each IP address
• Target Primitive - One for the system
• LUN Primitive - One per LUN
• Device Primitive - One per device (may include a clone primitive)

These are controlled through the following mechanisms:

I have just finished debugging an iSCSI storage system where the I/O on the disk appeared to be significantly higher than the I/O coming from the running programs. I discovered that the top of the iotop program can confirm this:

Total DISK READ : 63.46 M/s | Total DISK WRITE : 42.03 M/s
Actual DISK READ: 15.28 M/s | Actual DISK WRITE: 112.13 M/s

Having built a number of iscsi target systems over the years, I have consistently come back to SCST as my preferred implementation. Reasons have varied from IET crashing under load (doe not handle error conditions correctly), LIO crashing in early releases or not supporting naa_id (which is needed for vmware to mount a filesystem if the LUN id changes, or is different for different clusters).

There are 2 parts to this that I would like to note. First, in order to get drbd, iscsi and multipath to play nicely together under systemd, I had to do the following:
Create /etc/systemd/system/drbd.service.d/override-after.conf with the following contents:

[Unit]
After=systemd-modules-load.service network.target open-iscsi.service dev-mapper-bhqibm01\x2dr6\x2dsata01\x2dlun01.device
Requires=dev-mapper-bhqibm01\x2dr6\x2dsata01\x2dlun01.device

I also had to edite each of the /etc/iscsi/nodes/_iqn_/_ip_/default files and set:

Windows password policies through GPO are applied at the computer level. If a GPO is with a computer password policy is applied at the top “domain” level, it affects all users in AD. If a GPO with a computer password policy is applied at an OU level, it affects all local accounts on any computer that is in the affected OU tree.

I recently had a look at a few linux deduplicated filesystems, namely opendedup, lessfs and ddumbfs to act as a backup repository storage.

I was frustrated with opendedup because if would return "filesystem full" when there was no obvious reason why the filesystem might be full. As a result, I did not feel confident that I could safely monitor the system to alert me prior to the filesystem filling up.

Lessfs was too slow in my environment using the berkelydb and tokyodb backends, and I could not get hamsterdb to make a clean filesystem

If you want to mount a multipath device during system boot, you need to install the multipath-tools-boot package.

The base Debian config for multipath looks something like this:

I needed to change the firewall profile for a network adapter from public to private in windows server 2012. The only way I could work out to do it was using the following registry edit:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Profiles\{}

The value of Category is set as follows for the firewall profile:

Public = 0
Private = 1
Domain = 2

You need to match the detected network setting with the ProfileName key under the GUID, and modify the Category value as required.