Operating Systems





Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers. For large systems, the operating system makes sure that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system. Operating systems provide a software platform on top of which other programs, called application programs, can run.

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hello i have a mining program running on W10pro which crashed from time to time. the OS appears fine and other application continue to run but the mining program will close.

i'm looking at all avenues of fixing this is the long term but as a short term fix i'd like help putting together a bat file that will do the following:

on OS boot up start MyProgram.exe automatically

If MyProgram.exe appears to close wait for say.... 30 seconds and restart MyProgram.exe
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I want to know how can I start a script at the system startup. I tried to make a sh file under /etc/rc.d/rc3.d/ but I rebooted the Os and it does not start my script as I want. :(.

Windows server manager RSAT will not open but you see the process under task manager.  Started a few days ago tried multiple fixes ended up reloading OS from scratch and still same issue server manager wont open.  Windows 10 for Workstations 1803 is the current OS version.  Any Ideas
How to measure disk I/O throughput on a Linux OS. Any good tutorials on Sar, Iostat, etc would be highly appreciated.
My company has setup an Ubuntu 18.04 server, to exchange files with a client, via SFTP.  We need a high level of security.  We're trying to require authentication with SSH key pairs, AND the Linux OS username and password (not the SSH passphrase). We've got the key pairs working, but it doesn't ask for the password. I'm assuming we're just missing something in the sshd_config file. Hopefully we're not trying to do something that's not possible. Any assistance would be much appreciated.

I am having printing issues when printing a document or test print to local printer or network printer.  I am getting an access denied.
I have look at other posts but none seem to answer my question.
OS - Windows 7 Pro 64bit
Does not matter who I login as - domain user, local account, admin account all get the same error.
I have deleted all printers, deleted all printer software from programs and deleted printer form print management.
Re-installed the local printer (USB) first from fresh download, updated the firmware on the printer  with no issues.  Once I attempt a test print or print from program get the same issues.  I cannot print to a file using Adobe print either.
i have 2 hosts on vmware cluster ( vcenter 6.7 and esxi 6.7)  ..  I want to achieve the below scenario

vm1 will be on host 1 ( vm1 will be Primary server )    , IP : (e.g.)  
vm2 will be on host  2(vm 2 will be Secondary Server) ,IP : (e.g.)

both will be identical

I want my users to login to this ip (e.g.) as interface for the above IPs  so when any kind of problem happens to host 1 it directs them to the second host

can this be achived through vmware ?
or it should be done from os side ? ( using linux redhat and will use  pacemaker cluster)

thank you
I have a user that is getting access denied when trying to run Task Manager on Win10, below is what was done:

- SFC /scannow (no errors found)
- DISM Restore health
- Updated from 1703 to 1709, no change
- Updated to 1803, no change
- No other symptoms
- Logged in as a local admin and a domain admin and get the same results
- Pathing out to the EXE and also trying from an elevated CMD prompt gives the same results

I am needing advice to see if there is anything else to try besides a full OS reload
I have an early 2008 Mac Pro tower (upgraded Ram & Video) using El Capitain plus a Bootcamp 6.01 Win7 installation on a Separate internal HDD.

I want to install a new Win7 partition on my Mac OS HDD (250 GB of free space) while maintaining my existing Win7 installation on its separate drive.

Thus, I will end up with 2 BootCamp Win7 partitions, one new and the other old and worn out.

My purpose is to create a Fresh Win7 installation to which I will gradually copy and reinstall 10 years of Docs & Applications from my existing over-taxed Win7.

Where do I begin?  I assume I need to create a new Bootcamp partition on my Mac OS HDD, currently a single partition.

Just not sure of the best way to go about that without screwing up either my Mac OS or existing Win7 installation and data!


I have deployed my code on two machines M1 and M2.
They fetch a USer Object which contains details about name, designation, emailID etc corresponding to a userId.
Currently i am storing them in cache like this :

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
    private Cache<String, User> userCache;
 userCache = CacheBuilder.newBuilder()
                .expireAfterWrite(60, TimeUnit.MINUTES).build();

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But i just realized that there will be two caches on M1 and M2 separately. That could be an issue because say M1 caches data for a user. But the load balancer than sends the request to M2 and it will have to again fetch data.
what are the possible solutions to this ?
I can think of keeping another machine with all the cache data in RAM.
And so create a cache on M1 and M2 that programmatically connects to this machine.
But then comes the problem of having one more replica of this machine because in case one is down then
we still have data access...
Please suggest what is used to solve this type of problem ?

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Where exactly is a computer cache placed. Please suggest a good article on cpu cache.
Can i determine the speed of cache/RAM/disk on my laptop through some software ??
Also can one programmatically store data in cache ?
Normally we can use program to store data in RAM or disk. But is there an alternative to this ??

I recently stood up a new secure Ubuntu image and I am running nexpose on it.
Nexpose is configured to send email notifications when the scan starts and completes.
We have confirmed that nexpose is sending the emails;

2018-08-03T22:13:19 [INFO] [Thread: critical-task-executor1] Sending report to <correct recipient>.
2018-08-03T22:13:19 [INFO] [Thread: critical-task-executor1] Creating SMTP session to localhost:25
2018-08-03T22:13:19 [INFO] [Thread: critical-task-executor1] Delivered mail to <correct recipient>: 250 2.0.0 Ok: queued as 4BD9583179

But the reports are never being received.
I have been asked by the exchange person which SMTP relay server I have been pointing at.
I haven't been able to identify this question.
In Nexpose my configuration was imported from our old server so that should be the same.
The only thing I can think of is that some setting needed to be set on the OS side to get the emails to the SMTP relay server.

We are using postfix on the new image.
I have been searching for a place to configure the SMTP relay IP I was given but I haven't been able to find it.
Could someone point me in the right direction?

Suppose there is file which has "rohit bajaj" written in it.
Now suppose two users login to a machine and cd to this file location both having read/ write access to this file opens the file and they modify it to --

1) First user
rohip pakka

2) Second User
pohit pakaj

And they save the file at the same time.
what will the file contain ? Or what are the possibilities for its content ?

Two clear possibilities are that the changes of user1 or user2 only are visible. Is there any other possibilty ? Kind of mixup of both ? and how ?

we are having issue with 1 file server.
the space is rapidly decreasing

 We are running out of space at the OS level every week by

we are losing 60gb of space every 2 weeks

tree size wont help here to check the OS ?

the file server is vm
How can I allow read/write permissions to the C://Windows folder?  I am using Windows 7 64 bit OS.  Thank you.
I have a large mailbox for and exceeding everyday, I had an acrchive file on My Windows machine, but now I am not able to use the archive on Mac OS. Is there any solution to use/see archive file on Mac system? If yes how?

I installed dietpi today on a Zero w. (did it on a 3B+ and setup as Hotspot no problem). I wanted to setup the zero as a webcam.
I did this 4 times before I started to install or change the configuration and reboot at least 2 times to make sure all was good.
I changed the setup to US. connected to the Wi-Fi.
Updated to the latest version of dietpi. Update the firmware.
Changed drop bear to ssh.
installed REALVNC.
But when I Install RPI WEB CAM it keeps rebooting and I can't stop it.
As I said after the 3rd time I flashed a fresh image again and rebooted at least 2 times after each change or install until I got to the RPI Web CAM issue.
I get "You're in emergency mode. Enter root password for maintenance or CTRL D.
I tried dietpi for the password and root. CTRL D does nothing but reboot back to the same area.
I'm assuming there is am issue with RPI Web Cam.
And Yes I made sure the power supply is good. I replaced the power supply with one used on my Pi3B+. It's 5.2V, 3amps.
I even tested it with my voltmeter. The issue is this pi Zero W setup works fine with a full version of Raspian and the RPI WEB CAM version I had to manually configure. I switched back to that card and all is fine. I just like the small footprint and ease of setup with DietPi. And it only starts to reboot when I add in the Web Cam distro on DietPi. I even tried some other packages after my 4th attempt, on the card, flashed a new image. In fact I added a few distros to the DietPi setup …
Random websites unreachable on certain Mac computers running varying versions of OSX. Only seems to be affecting Mac computers, although not all of them.  I thought it might be related to our router, but I bypassed it and hooked the problematic machines directly to the cable modem and the issue remained. So my thought is there has to be something going on within the OS that is causing this. All browsers accessing the problematic sites act the same (Chrome, Safari, Firefox). The websites that are unreachable are seemingly completely random. Some include Gamestop.com, mycymbal.com, and barclaycardus.com. Pinging any of these sites via terminal gives a "request timeout", "host is down" error. Traceroute in Network Utility also results in "Host is down" error. In both cases the IP address of the host gets successfully resolved, but is unreachable.

I have no antivirus running on these machines. It's happening on Macs running 10.10.5 and 10.13.6.  Meanwhile, none of the PCs on the network seem to have the issue. This is really a frustrating head scratcher. Any troubleshooting ideas are appreciated!
Hi, I need to install an additional DC on a network where already exist two 2008 R2. This controller will be a VMware virtual machine (ESXi 5.5).
Workstation are Windows XP, Windows 7 and Windows 10.
I can only find OS license for Windows Server 2016.
Do you suggest me to buy a license for 2016 and ask downgrade to Microsoft (to 2012)? Is it feasible?
Thank you
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Cloud Class® Course: MCSA MCSE Windows Server 2012

This course teaches how to install and configure Windows Server 2012 R2.  It is the first step on your path to becoming a Microsoft Certified Solutions Expert (MCSE).

I set up a server host OS and a VM in Hyper-V as a domain controller on a PC with a couple SSDs. When I got everything working, I cloned them over to a PowerEdge T330. Now my Hyper-V DC will not work with a static IP address. It cannot see the network PCs, ping out, or access the internet. If I set it to DHCP, I can access the internet, but nothing internal. I am at a loss as to why this is happening, however, I need to fix this as soon as possible. Does anyone have any ideas?
Client doesn't remember their password  for Mac mini (late 2012) so unable to Add helper to install High Sierra or add users for Windows shares.
OS X 10.8.5 (12F2560)

Need to share files with Window(SMB)
cannot open webpage SanMar

My guess is that the update would fix the website issue but can't get past the password. FileVault is not on. Their is no option to use Apple ID to reset password. No other admin accounts on the machine.
How would one go about upgrading MacOS devices to the latest OS (High Sierra at the time of this post) through terminal commands only?  For example, a device running El Capitan needs to be upgraded to High Sierra.  I am looking to run this command across multiple MacOS devices, and for a command or script that could run on any MacOS device.
Client has a Windows Server 2008 R2 machine. It is a 64 bit machine, however it has reserved half of the 8 gbs of RAM for "hardware" leaving only 4 gbs  usable for the OS causing any file transfer or job across the network to be very slow. Any ideas on how we can resolve the issue?
Not able to access a dev site from the VPS server's ip address.  Hosting company says all configured correctly on the VPS and that I need to add the IP Address and domain to hosts file.
Is there a trick to updating hosts file on this Mac OS 10.13.6 version?  I've used sudo nano /etc/hosts added the server IP address and the domainname.com and ran the sudo killall -HUP mDNSResponder && echo macOS DNS Cache Reset.

Help with getting this working would be appreciated.
We need to upgrade our Server 2008 Enterprise SP2 to 2008 R2. We have to do this across several servers on our network. This is a host to multiple VM's. We gathered as much information as possible. Any advise to be on the lookout for after the upgrade?

Operating Systems





Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers. For large systems, the operating system makes sure that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system. Operating systems provide a software platform on top of which other programs, called application programs, can run.