All posts by l4urenz


The Office 365 ProPlus update model supports 4 production channels;

  • Monthly Channel (Targeted),
  • Monthly Channel,
  • Semi-annual Channel (Targeted),
  • Semi-annual Channel.

Each channel receives features updates, security and non-security updates on different release intervals.

Consider a scenario where Office 365 ProPlus is installed on a machine from the Semi-Annual Channel.  Now let’s say, a new feature is introduced on the Monthly Channel which you would like to get.  Since you are on the Semi-Annual Channel you will have to wait for a few months before this feature is made available to the Semi-Annual Channel.  But what if you do not want to wait that long?  The answer is, switch to the Monthly Channel.

Switch Channels

Below are the steps to switch channels:

  1. Identify the channel which you would like to switch to. Features and updates by channel are documented here.
  2. Launch Command Prompt as an administrator.
  3. Navigate to “C:\Program Files\Common Files\Microsoft Shared\ClickToRun\”
  4. Run the following command to change the desired channel, let’s say Monthly Channel Targeted “OfficeC2RClient.exe /changesetting Channel=Insiders” (When running in powershell the command will be “.\OfficeC2RClient.exe /changesetting Channel=Insiders”

or if you want to switch to the Montly channel:

OfficeC2RClient.exe /changesetting Channel=Monthly”

Note – You can use this command to switch to any channel using the corresponding Channel keyword listed below:

Channel Keyword in CMD or ODT
  Monthly Channel (Targeted)   Channel=”Insiders” or Channel=”FirstReleaseCurrent
  Monthly Channel   Channel=”Monthly” or Channel=”Current
  Semi-annual Channel (Targeted)   Channel=”Targeted” or Channel=”FirstReleaseDeferred
  Semi-annual Channel   Channel=”Broad” or Channel=”Deferred

To start the switch Channel process, run “OfficeC2RClient.exe /update user” from the cmd prompt path “C:\Program Files\Common Files\Microsoft Shared\ClickToRun>” This should be followed by a series of windows which will take you through the process of downloading and installing updates for the new channel that you have switch to.

All credits go to Eric Bierens, this is just a shameless copy-past for personal usage.

Speed up Synology SHR Raid repair.

Rebuilding SHR arrays can take a long long time.
But we can solve this by the might SSH / CLI.

SSH into your DiskStation. To view the status of your rebuild:

$ cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] 
md2 : active raid5 sdd5[6] sda5[5] sde5[7] sdc5[2] sdb5[1]
      7795118592 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/4] [UUU_U]
      [=>...................]  recovery =  5.2% (103271424/1948779648) finish=672.9min speed=45708K/sec

Initially, the rebuild speed is 45708 Kb/sec (~45 Mb/sec), with an estimated completion time of 670 minutes, or 11 hours so so.

We can go faster!

RAID rebuilds are speed limited. The default minimum and maximum speeds are, in Kb/sec:

$ cat /proc/sys/dev/raid/speed_limit_max # maximum speed
$ cat /proc/sys/dev/raid/speed_limit_min

Let’s increase that minimum speed a touch:

$ sudo su
# echo 50000 > /proc/sys/dev/raid/speed_limit_min

And see if we’re going any faster:

# cat /proc/mdstat 
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] 
md2 : active raid5 sdd5[6] sda5[5] sde5[7] sdc5[2] sdb5[1]
      7795118592 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/4] [UUU_U]
      [=>...................]  recovery =  7.3% (142689152/1948779648) finish=543.4min speed=55388K/sec

Yeah, it’s a little faster – up to 55 Mb/sec with an estimated completion two hours sooner.

# echo 100000 > /proc/sys/dev/raid/speed_limit_min
# cat /proc/mdstat 
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] 
md2 : active raid5 sdd5[6] sda5[5] sde5[7] sdc5[2] sdb5[1]
      7795118592 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/4] [UUU_U]
      [=>...................]  recovery =  8.4% (163878932/1948779648) finish=356.4min speed=83448K/sec

I played around, and with a speed_limit_min value of 100000, we hit a bottleneck and max out at about 85 Mb/sec, but thats pretty much twice as fast as we were going. Not bad. (Note to self: return to default value when the rebuild is finish.

Diskcleanup on 2008 R2

Have you ever found yourself missing the “disk cleanup”  tool to clean a server or of its much needed C:\ space. Wait no longer..

First stop could be, to install the Windows Desktop Experience feature, but this requires a reboot and will install also other application, you might not want..

So how about, if you could just copy 2 files and run the application.


Operating System Architecture File Location
Windows Server 2008 R2 64-bit C:\Windows\winsxs\amd64_microsoft-windows-cleanmgr_31bf3856ad364e35_6.1.7600.16385_none_c9392808773cd7da\cleanmgr.exe
Windows Server 2008 R2 64-bit C:\Windows\winsxs\amd64_microsoft-windows-cleanmgr.resources_31bf3856ad364e35_6.1.7600.16385_en-us_b9cb6194b257cc63\cleanmgr.exe.mui
Windows Server 2008 64-bit C:\Windows\winsxs\amd64_microsoft-windows-cleanmgr.resources_31bf3856ad364e35_6.0.6001.18000_en-us_b9f50b71510436f2\cleanmgr.exe.mui
Windows Server 2008 64-bit C:\Windows\winsxs\amd64_microsoft-windows-cleanmgr_31bf3856ad364e35_6.0.6001.18000_none_c962d1e515e94269\cleanmgr.exe.mui
Windows Server 2008 32-bit C:\Windows\winsxs\x86_microsoft-windows-cleanmgr.resources_31bf3856ad364e35_6.0.6001.18000_en-us_5dd66fed98a6c5bc\cleanmgr.exe.mui
Windows Server 2008 32-bit C:\Windows\winsxs\x86_microsoft-windows-cleanmgr_31bf3856ad364e35_6.0.6001.18000_none_6d4436615d8bd133\cleanmgr.exe

Once you’ve located the files move them to the following locations:

  1. Cleanmgr.exe should go in %systemroot%\System32.
  2. Cleanmgr.exe.mui should go in %systemroot%\System32\en-US.

You can now launch the Disk cleanup tool by running Cleanmgr.exe from the command prompt.


Windows KB page

Installing MemCached

Memcached is a high performance in-memory caching system that can be used to speed up applications and websites that use databases. Memcached does not write to disk, instead store its content in system memory which makes it faster.

Majority of the content management systems in used today have tools to take advantage of Memcached. If configured correctly, you may be able to see huge improvements to your websites and applications.

This brief tutorial shows you how to install Memcached on Ubuntu 17.04 / 17.10 servers

Continue reading Installing MemCached