Remote Symbolic Links – Redirecting fileserver data

So we had this problem, several of our Windows 2008 R2 fileservers were running full and due to technical issues (old hardware) replacing the disks became VERY expensive.

So alternatives, I started to thing – hey, lets create an “ISCSI drive” on a remote datacenter server, mount the ISCSI drive into the directory structure as a mountpoint named “Archive” or something.  Now users could put “old” archival data here, thus removing it from the server but still being available – clever 😀  A few issues crept up however, when creating an ISCSI target on a Windows 2008 R2 server this is “terminated” as a VHD file – this proved annoying (eg for backup etc), besides a friend of mine pointed out that they had tried something similar once – sadly if connectivity was sketchy this could cause the fileserver to hang as it was unable to connect to the iscsi target.

My friend however pointed out that he had had success with using “Links”, right – I have heard of these Junction points and symbolic links, but never really found any real good use for it.  But it turn out you can create a symbolic link from the directory structure on one server, pointing to a share on a different server.

So eg. O:\ could have a lot of directories, however we also make a Symbolic Link there named “Archive” – if you now perform a dir you will find all the subdirectories, however you will also find O:\Archive which looks just like a directory (the icon gets a screwy arrow but thats all) however it’s not, it is instead a “pointer” to a share on a different server (this share we can easily backup and maintain).

So the command to use is;

MKLINK /D <NAME> \\<SERVERNAME>\Sharename

2017-02-04 23_22_50-mRemoteNG - confCons.xml

eg,  MKLINK /D HyperVisor5 \\SECRETSERVER\aarhus

HyperVisor5 is the name the directory will get locally the /D indicate it is a directory junction, and the link will point to \\SECRETSERVER\aarhus (aarhus is the share name on the SECRETSERVER)..

2017-02-04 23_23_46-mRemoteNG - confCons.xml

Ohh that was easy you say, yeah – well – it did not work 🙁

2017-02-04 23_18_39-mRemoteNG - confCons.xml

When a workstation attempted to access a mapped drive (eg. O:\Archive) it would get the above error.

A bit of googleing let to;
https://blogs.msdn.microsoft.com/junfeng/2012/05/07/the-symbolic-link-cannot-be-followed-because-its-type-is-disabled/

And the solution was simple enough, you need to execute this command on the workstation that has the problem;

2017-02-04 23_46_00-mRemoteNG - confCons.xml

(the command above the yellow one show the state of your computer)

And now your workstation can browse the directory (which is actually a pointer to a share on a different server) just like it was on the local server.

This should also be controllable via Group Policy, however I have not had the chance to test it yet;

https://technet.microsoft.com/en-us/library/5c7ffdb9-7066-4bdf-bc7d-eded8db2ce82
The symlink evaluation settings can also be controlled via Group Policy. Go to Computer Configuration > Administrative Templates > System > Filesystem and configure “Selectively allow the evaluation of a symbolic link”.

 

 

Cluster nodes create ’emergency’ file

A consultant mentioned a rather cool trick to me some time ago, and I think it’s worth a mention here.

We have a Microsoft Hyper-V cluster with 3 nodes, now these nodes have something called “Cluster Shared Volumens” which is their disk-pools – an annoying fact about these is that this “shared volume” is not represented as a drive letter so regular monitoring of diskspace does not warn you about low disk space – this particular problem was resolved via a script on our MS-Scom server but that is not “the trick”.  The trick is, let’s say that the “Shared Volume” is low on diskspace on a Friday and run out of space during the weekend – now how do you with the least downtime get it back online?  Sure you can log in to your san, expand the disk and then to the server and extend the volume, but all of this takes time and is a bit tedious via your smart phone when it happens Saturday night when you are at the cinema with your girlfriend 🙂  The trick is to create a ‘dummy’ file on the shared volume that you simply can delete once diskspace is depleted thus freeing up space in a second – let’s say you create a 5 – 10 or 15 GB file that you can simply delete freeing up 5 – 10 or 15gb of diskspace in a second this could really save your weekend 🙂

Anyhow, it’s quite easily done via a buildin command in Windows;

This command will create a file called emergency;

15gb;
fsutil file createnew emergency 15000000000
10GB;
fsutil file createnew emergency 10000000000
5GB;
fsutil file createnew emergency 5000000000

once you run out of diskspace you simply delete this “emergency” file and immediately free up space causing the least downtime and possibly buy you time to regular business hours, quite simple but yet clever.  The single drawback is obvious you ‘waste’ the diskspace you are reserving – but hey diskspace these days cost so little so it’s hardly worth mention.

An advancement of this trick would be to implement automation – so that the ’emergency’ file would be erased automatically if the “Cluster Shared Volume” run out of disk space.

Hyper-V performance monitor – Free tool

I just stumbled across this nice little free util, it’s sort of a taskmanager for your Hyper-V server..

Cool it’s free, however I’m slightly sceptical when it comes to the performance it reports – I feel my server should be under a more heavy load – but hey I’ll give it a spin and see how I like it.

get it here;
http://www.manageengine.com/free-hyperv-performance-monitor/download.html

DOSbox – the perfect dos emulator

Have you some old MS-Dos program lying around that you for some reason wish you could run, but as you installed Windows 7 64bit this is not possible!?

Well then this is for you, DOSbox is a free dos emulator that does a REALLY good job of executing these old apps.  It will even emulate a SoundBlaster Pro soundcard so you will be able to get sound and all.  So if you have Monkey Island I lying around somewhere now is your chance to get all nostalgic 🙂  Oh yeah, it is as with so many other cool things FREE 😀

http://www.dosbox.com/download.php?main=1

Watch how it can even run old DOS demos;

MobaLiveCD – a fast way to test a bootable ISO.

On the subject of ISO files (previous post), if you have downloaded a bootable ISO file and want to do a quick preview of it – then try MobaLiveCD.

MobaLiveCD is a quite simple little utility that will provide an instant emulation of a system, thus you start MobaLiveCD and tell it to ‘boot’ the ISO file of your choice and BAM without any fuss you will see the menu of this CD/DVD.  Really cool.  Ok, one minor issue with this is that the speed of the thing is not great, for starting small menu driven cd’s/dvd’s it’s great but for starting a Linux live cd it is hopeless – so I guess it’s more a tool to quickly see what’s on a cd/dvd than a virtual pc kind of thing – but hey it is free.

http://www.youtube.com/watch?v=Uwwdv9TJah0
Available in HD


http://mobalivecd-en.mobatek.net/index.php

Mounting ISO files

Once in a while you get hold of an ISO file (an ISO file is basically just an image of a CD/DVD/BLUE-RAY disk) and need to access the content of this file, there are several ways of doing this;

1) You can burn the ISO file to a media and read it this way.

2) You can extract the ISO file to a folder using a utility (WinRar is very good at this).

3) you can mount the ISO file as a virtual CD/DVD eg. use Deamon tools lite.

I would suggest option 2 or 3.

Anyhow, David Davis has written a nice beginners guide on the subject, so be sure to check it out at;
http://www.windowsnetworking.com/articles_tutorials/Mounting-ISOs-Windows-7-Free-Tools.html

Sparkle Sparkle little server

http://www.sparkleshare.org/ is a new project on the Internet inspired by Dropbox (a clever fileshareing/collaboration and file syncronising util that uses cloud based storage), SparkleShares force is that it supposodly will be free/open source and you can thus setup your own servers, sounds like something to make a mantal note of..

The first version will be in Linux but should be followed by a windows version, presently no version is publicly available though (as it’s very early in the program, announced June 10th 2010).

http://www.omgubuntu.co.uk/2010/06/sparkleshare-aims-to-better-dropbox.html

VMRCplus for MS-Virtual Server 2005

If you ever (god forbid) have to support Microsoft Virtual Server 2005 then this is the tool to use;

http://www.microsoft.com/downloads/details.aspx?FamilyID=80ADC08C-BFC6-4C3A-B4F1-772F550AE791&displaylang=en

It is by far better than the native tools/website.

Microsoft App Virtualization – the fun never ends

So as described earlier I was messing with Softgrid (now Microsoft Application Virtualization) and had some issues getting it to work, so I decided to move to the latest version (thus the name change), we was using 4.2 and the latest version is 4.5.

Anyhow, I upgraded the sequencer and everything seemed fine, I started a capture and everything seemed fine until I started the Java installer, i now got an error from the MSI installer;

javafejl

Error 1719.The Windows Installer Service could not be accessed. This can occur if you are running Windows in safe mode, or if the Windows Installer is not correctly installed. Contact your support personnel for assistance.

Odd I thought and tried different approaches which all led to the same error.

A bit of googling led me to this;
http://social.technet.microsoft.com/forums/en-US/appvbeta/thread/1c5f8f8f-d431-4b7f-9601-40c1aef0409c/

The problem is simple yet bizzar, you can’t use remote desktop while doing a capture!?!?  I was using a virtual pc (HyperV) and used remote desktop to connect and do my capture, however once I restarted the Virtual Machine and did the capture via the HyperV console there was no problem!?  Odd…

Softgrid tool and guide

So I had to brush a bit up on my Softgrid knowledge for a package build and I came across a few things I’d like to share;

  1. A super guide to Softgrid building by one of the Guru’s on the field (Chris Lord).
    http://myitforum.com/cs2/files/folders/120058/download.aspx
  2. A neat util to explore Softgrid packages without installing the sequencer. SFT Explorer.
    sftexpl_screenshot_tb
    http://www.virtualapp.net/sft-explorer.html

As of right now I haven’t really gotten my package to work, I have to include an old version of Java with a link to a web-site.  But even if I set the registry to override it still fail to launch the old java, if no java is on the machine in advance it works like a dream..  We are currently using the old 4.2 sequencer so I might try the 4.5 version to see if any improvements has been made.