Handige Knakker

All those ways to get the size of directories with powershell are extremely slow. Especially on network shares.
e.g.

$colItems = (Get-ChildItem C:Scripts | Measure-Object -property length -sum)
"{0:N2}" -f ($colItems.sum / 1MB) + " MB"

Currently i’m harvesting through roughly 40TB of data and it’s taking me daaaaaaaaaays!
So i’m in desperate need of something faster.
Then i thought about robocopy. Robocopy gives great statistics. So if i do a “dry-run” (list-only, not really copy), i might get the information i need by parsing the output.

Choice of switches:

• /b = backup mode. Supposed to give me access to every file
• /l = list only/dry-run, not really doing the copy
• /mir = action what you would normally do when you would copy the data. This also dives into all subdirectories.
• /r:0 = no retries
• /w:0 = don’t wait on anything
• /ns /nc /nfl /ndl /njh = no logging of any kind. We only want the summary.

Then we get this piece of code (it could be a lot shorter, but i’m keeping it readable):

function get_size_of_dir_in_bytes_with_robocopy ($directory)
{
  write-host "- $directory" -foreground "GREEN"
  [string]$result = robocopy /b /l /mir "$directory" "c:\whatever" /r:0 /w:0 /ns /nc /nfl /ndl /njh /bytes
  if (!($lastexitcode -eq 16))
  {
    $pos = ($result).indexof("Bytes : ")
    $start = $pos + 8
    $length = $result.length
    $end = $length - $start
    $newstring = ($result).substring($start,$end)
    $newstring = $newstring.trim()
    echo $newstring.split()[0]
  }
  else
  {
    echo "CANNOT ACCESS"
  }
}

add the following lines to /etc/sysctl.conf

# IPv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

… and reboot.
Or simply reload the settings:

sysctl -p

2019 update:
sysctl.conf still works, but it won’t be processed during boot.
Therefor recent Ubuntu’s need an extra grub parameter ipv6.disable=1. Like so:

GRUB_CMDLINE_LINUX_DEFAULT="splash quiet ipv6.disable=1"
GRUB_CMDLINE_LINUX="ipv6.disable=1"