Remotely turn on remote desktop

Sometimes you need to access a PC remotely, but remote desktop has not been configured. What can you do without being in front of that PC?

Follow these instructions: Remotely turn on RDP

A very usefull article!

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openmediavault further steps…

Some time passed since I installed openmediavault on my new small server.

I was just thinking that it would have been simple to work on, but the web interface seemed to freeze on several configuration command. I thought I was using a bad UI, but a simple search on the forum lead me to a worst case scenario: one of the drive was really failing in my server.

As I mentioned in my previous post, something weird had probably happened during transport, as I found an unpinned heatsink. But maybe also the disk had its faults (I hope it gained those too during the transport).

So what now? I’m planning to replace the faulty disk with a new spare disk as soon as possible, to see if every problem goes away and I will be able to fully test openmediavault.

Let’s see…

First experiments with OpenMediaVault

In August I wrote about my new gadget that I bought on eBay.

It’s basically a 1U micro server with two non hot-swappable 1TB disks, 8GB of RAM and an AMD Opteron quad-core 64bits CPU.

Well it arrived and I started doing some experiments on it. At first I wanted to install NAS4Free, a FreeNAS derived distro focused in storage management. My intent was to install it on a USB key, to leave the two disks available for data storage. But it wasn’t so easy to install: installer refused to go beyond network card initialization, so I thought that my new used server was faulty. So I used a Knoppix bootable media (a DVD version written onto a different USB key) to give a look on the system and test RAM with memtest86. It seemed all ok, so I tried another time with the installer, but even in this case with no luck.

Then I tried the original FreeNAS distro, assuming that it was better developed (it’s now a commercial product), but even that didn’t work. Googling around there are some reports on AMD Opteron CPU and FreeBSD, the distro on which both the NAS distro are built on. As I’m not familiar with the *BSD environment as I am on Linux, I took a totally different direction.

On my favorite channel on YouTube, MyPlayhouse, I came in contact with Xpenology distribution. This is basically a way to install a Synology proprietary operating system on a PC hardware. This is a experimental setup, that will give you the opportunity to test a really good built and Linux based NAS-like distro. I’m not going deep on that installation here, there is a lot of documentation on the web about it; I just let you know that it worked pretty well for some time, so I was convinced that my hardware was not fault, … well not at most.
In fact when I was building up a RAID 1 array the first time, one of the disk was inhibited to be used; the reason? SMART reported that the sector reallocation count was too high. Ouch! I tried to test it but system freezed several times, so I gave up and turned all off, and bought some 1TB used replacement drives. When I was to replace the defective drive, I thought I would have to give it one more try, and all errors disappeared… Why? Maybe during transport some cable were loosened, and when I touched all of the stuff inside I put it to work again.

When I was digging in the inside, I noticed a passive cooler was hanged to the mainboard only with one plastic pin; the other one with it’s spring disappeared… Maybe some of the reported errors was given by overheating of the controller chip. I then replaced the missing pin, but first put some silicone grease under the heatsink, and tried again to install something…

My last choice was OpenMediaVault, another free and Linux based distro. It can be installed from an USB key onto another USB key, and it’s pretty stable, full of features and widely used.

It’s installation process was pretty straightforward, but as I didn’t have more time to spend in front of the monitor, I launched it and went to work. When I got back home, monitor was off, no signal, and server was powered down. Tried again on the following day, but is sounded worst: after some time the monitor started flickering: VGA signal started going away randomly, even in BIOS screen, so I thought that my server time was arrived…

I tried the last time to install OMV from the beginning, this time waiting in front of the screen… And this time it all worked!

Now I have my OMV system installed and running, I just have to perform the disk partitioning and start using it.

A new gadget is coming…

Even during holidays I can’t resist watching eBay and similar sites. And thanks to YouTube channels I’m following (first of all My PlayHouse), I decided to buy a new 1U server to join to my DELL PowerEdge in my data center.

It’s basically a 64 bit dual core Opteron with 8GB RAM and 2x1TB SATA disks.

I’m planning to use it as a NAS with FreeNAS to share an iSCSI device for my ESXi host running on the DELL PowerEdge.

More info coming when the device will be in my hands..

GDB online Debugger | Compiler – Code, Compile, Run, Debug online C, C++

A colleague brought my attention to this awesome site: www.onlinegdb.com. From here you can freely test and even debug your code snippets in C/C++, C++14 and even also other languages like PHP, Java and js.

A must-have link in your bookmarks. It worth a look, give it a try.

Workstation re-join to domain

microsoft_p73_05967_windows_server_2012_r2_1025605Sometimes… it happens.

You have a joyful domain with some workstations in it, and suddenly a workstation decides (or the PDC decides for that) that it would be great to exit the domain. And just to be sure you won’t understand what happened, when a legitimate user wants to logon it obtain such a message from the login attempt:

The trust relationship between this workstation and the primary domain failed.

There are many causes (human in front of all) for a workstation to leave a domain. But behind prevention of this problem, how can we solve it once it happened?

It happened yesterday to a Client of mine and I was asked to solve the problem. I had to Google around a little bit, but looking for the above message let me found some information about the problem itself and some workaround. All of those requires you to access your workstation with a local administrative account, but what if that workstation has been installed years ago, not by you, and nobody knows who is the local administrator and/or the password (even the person that is supposed to have installed that workstation)?

Well I found this workaround that at least let me enter the workstation, make the appropriate adjustment and then solve the problem. I can’t assure this will work again or it will work for you, but it worths to try.

  1. disconnect network cable (or turn off WiFi). This is to ensure that the workstation won’t reach the PDC when requesting logon
  2. perform logon normally with the user account. You might ask how is it possible, as the network connection has been cut out in the previous step. This can be done because Windows locally caches credentials in the event the PDC is not reachable…
  3. reconnect network cable
  4. open Computer Management. You will be asked for an Administrator account to use; as we don’t know who is the local administrator on the workstation, enter domain Administrator credentials (and cross your fingers)
  5. If Computer Management appears, switch to the Local User and Groups definitions. If Computer Management does not appears… you have finished to follow this guide. You’d better search a different approach.
  6. Normally the local Administrator account is disabled, but at least one local user should belong to Administrators group
  7. Select that user and reset its password. As you didn’t remember the password before, you might want to take note of the new password somewere, in the event you’ll have to use it…
  8. Pressing WIN+PAUSE will bring you to the System Status. Here you have to select the Advanced Properties, and you’ll be asked for an administrative account again. You can use once again the domain administrator credentials.
  9. Select the Network Identification tab. You will see the PC is currently joined to the domain, even though this is not working. You have to select to join a Workgroup, then give it a name (for instance TEMPGROUP).
  10. You’ll be asked for credentials of a user which can unjoin workstation from domain. Once again you’ll have to enter domain administrator credentials. You’ll be warned also that a local (administrative) account must be enabled on the workstation. We ensured it on step 7
  11. Once did, we have to restart the PC
  12. Upon PC restarting you can access it with the local administrative account given in step 7
  13. Then you will press WIN+PAUSE once again, select Advanced Properties, navigate to Network Identification tab and select to join a domain
  14. Enter the domain name, then you’ll be asked for domain administrator’s credentials
  15. Enter them, and your workstation will re-join to the domain
  16. Reboot the PC and then logon as the workstation’s normal user

That’s it.

It worked for me to rejoin a Windows 7 Pro workstation to a Windows Server 2012 R2 domain. I think that it could be used with different Client and Server O.S.. Let me know!

 

News from “The Lab” – New server booting!

And finally my server is up, even though not running yet.

Even after trying to fix the backplane joints that seemed to be broken, it didn’t came up as I wanted it to do.

So I firstly purchased on eBay a replacement backplane, and tried it with no luck.

Then I finally got a replacement PERC 5i card, and I solved my problem with not recognized devices.

I only have to install ESXi and start playing now…

News from “The Lab” – New server faulty?

Today I think I found out what was blocking my new server from properly booting.

This is a close-up of SAS backplane.

It’s quite hard to see, but some pins of the main Cypress component are bent. A close look with a (cheap) PCB inspection microscope made me quite sure that this damage could prevent the PERC card to properly detect the backplane itself and, in turn, the disks.

I asked my colleague to fix the problem by reworking the joints, and tomorrow I’ll test if this patch works.

In the meanwhile I’m watching some spare parts on eBay… Murphy is always watching you…

Stay tuned!

News from “The Lab” – New server troubles…

As I recently discovered, my new server is not working as it should.

After some suggestions from my friends, I tried reseating all of the internal cards, starting from the PERC 5i controller and PCIe riser card. None of them made the server to properly boot.

As a last resource I removed the PERC card (the riser card cannot be removed because it’s used to connect the front panel, with power on switch, to the baseboard). Obviously as expected the F/W initializing , along with PERC BIOS messages, didn’t came up. Connecting only the card, removing connections with the SAS backplane, brought me to the conclusion that the problem could reside into the backplane or the disks. If I remove the disks I’m warned about their absence, but reinserting them doesn’t make any blinking LED to came up.

So I suspect that I have to look after some new disks to check and then pray that the problem is not due to a faulty backplane…

More coming…

News from “The Lab” – The new server

I decded to switch over to a new server, as the old HP Proliant was unable to handle 64bit virtual machines (due to lack of BEST in its processors).

I found a cheap Dell PowerEdge 2950 with two quad-core processors, 8GB RAM and two 146GB SAS disks.

But…

When I turned on the server after its installation, this message came up:

It seems that the PERC controller is not working… I just tried reseating it and the riser card, but no luck.

I will try to remove the controller to see if the message still persists, just to isolate the problem source.

If anyone has some ideas on how to troubleshoot this problem, please let me know.