How to resize a pdf without losing much quality in Linux Mint Ubuntu Debian Redhat Solution

Use gs or ghostscript as below, specify the output file and also the input file. In the example below the output file is "outputfile-resized.pdf" and the input file is "original-pdf.pdf". Change the input file to the name of your pdf gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/prepress -dNOPAUSE -dQUIET -dBATCH -sOutputFile=outputfile-resized.pdf original-pdf.pdf For........

efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.

This sometimes happens when trying to install the EFIversion of grub to a device when you are booted into Legacy/MBR mode. It doesn't seem to occur on all machines, but some and seems somewhat BIOS dependent. grub-install --target=x86_64-efi /dev/sda Installing for x86_64-efi platform. grub-install.real: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image.. grub-install.real: warning: Couldn't find physica........

nvidia cannot resume from sleep Comm: nvidia-sleep.sh Tainted: Linux Ubuntu Mint Debian

This seems to happen in many different drivers but it happened more often in newer versions such as 530 vs 525. Then nvidia-modeset goes to 100% There are many reports of this appearing since driver 4.70 and I can confirm I've seen this in various machines. https://forums.de........

How To Completely Disable ufw in Linux Ubuntu Mint Debian

This is for the situation that you're doing other things that may conflict or have your own custom rules and ufw keeps overriding iptables. A lot of guides don't work, and even ufw reset does not work, because it still leaves the old ufw chains. Here is what works to disable ufw completely systemctl stop ufw systemctl disable ufw ufw disable rm -f /et........

Linux Ubuntu Mint Gnome keyboard Typing not working in certain application or window solution

This is a weird issue in Mint Ubuntu gnome that I've only seen on one system. It may happen in your terminal or your browser but one program will just refuse to allow input from the keyboard. I am not sure if it's some weird fluke on a strange keyboard by perhaps accidentally hitting a weird key combination. In some windows the keyboard gets weird and only / and Esc seem to work. / brings up quick find and sometimes Esc will close it........

Virtualbox Best Networking Mode In Lab/Work Environment without using NAT Network or Bridged

Virtualbox is a very powerful tool, but for some use cases it is less than optimal. Say you are in a work, lab or other environment where you are not alone on the physical network and there could be overlap of IPs, but you need all of your VMs to be contactable from your host, VMs need to communicate with each other, and VMs need internet. NAT Network will give you VM to VM communication and internet, however, it is buggy and unstable. It also doesn't allow host to VM co........

docker / kubernetes breaks Proxmox QEMU KVM Bridge VMs

Docker adds iptables rules that break a lot of things including MASQUERADE or anything that needs the FORWARD table. If NAT is not working after Docker installation, it is probably because it set the iptables FORWARD policy to DROP. This may also make you think that your br0 or bridge is not working, but it's likely just due to what we'll mention later on below, that, Docker probably set your FORWARD chain to default DROP all packets, so nothing on your bridge ever makes it out........

Ubuntu Mint audio output not working pulseaudio "pulseaudio[13710]: [pulseaudio] sink-input.c: Failed to create sink input: too many inputs per sink."

If your audio is not working and you got this in your syslog: pulseaudio[13710]: [pulseaudio] sink-input.c: Failed to create sink input: too many inputs per sink. The issue is generally caused by too many audio inputs, or in other words you have too many applications that are hooked into pulseaudio. An easy and notorious offender is by having dozens of Firefox browser tabs open. Solution: Close all of your Firefox and the problem will........

Docker Tutorial HowTo Install Docker, Use and Create Docker Container Images Clustering Swarm Mode Monitoring Service Hosting Provider

The Best Docker Tutorial for Beginners We quickly explain the basic Docker concepts and show you how to do the most common tasks from starting your first container, to making custom images, a Docker Swarm Cluster Tutorial, docker compose and Docker buildfiles.........

How To Create OpenVPN Server for Secure Remote Corporate Access in Linux Debian/Mint/Ubuntu with client public key authentication

Why choose OpenVPN instead of a firewall appliance? OpenVPN can be a reliable and easy replacement for traditional hardware or just be an additional tool that your company uses so that the firewall can focus on its job rather than acting as a VPNappliance at the same time. When comparing OpenVPN with traditional firewal........

iptables how to delete rules based on source or destination ip port or just the rule itself

Let's say we have an IP that is dropped by iptables 192.168.20.2 service iptables status|grep 192.168.20.2 184 DROP all -- 192.168.20.2 0.0.0.0/0 You can use iptables itself like this to list the line numbers: iptables -L --line-numbers Two Ways To Delete The iptables Rule........

pulseaudio issue on QEMU/KVM guest VM when microphone is replugged/unplugged pulseaudio: pa_threaded_mainloop_lock failed pulseaudio: Reason: Invalid argument

Here is the scenario, you are using QEMU/KVM and are using something like the AC97 sound driver to pass the host audio to the guest via pulseaudio. This is useful because you can transparently pass your mic input from the host which means you can mute your microphone from the host, which prevents the guest from receiving any mic input even if unmuted. Mute / Unmute Fix This issue also seems to happen even if you press the mute button on the microphone and then unmute,........

Ubuntu Linux Mint - Volume Control Stopped Working

Volume control will often stop working, if your sound server (normally pulseaudio) dies or restarts whether by itself or by you. The reason pulseaudio may need to be restarted is due to some sort of crash or other issue that prevents sound from working (normally restarting or doing a killall pulseaudio fixes things). However, you will normally find at least in OS's like Ubuntu/Mint 16/18+ that you cannot control the volume whether adjusting the level, changing input/outputs and........

vi how to delete everything to the end of the line or the rest of the line from the cursor

vi is very handy when doing a lot of config file editing and can save you time over using the mouse or using the x or delete keys to manually delete. Solution: If you don't want it to stop deleting when encountering things like - or _, then you want this: d$ Or if you want it to stop on - and _ then use this: dw Remember both commands are in "non-input mode" so not when you're........

Cisco Howto Configure Console Port/Terminal/Comm Server with Async Cable Setup

This assumes that you've already installed the relevant HWIC cards eg. Cisco Asynchronous Serial NIM These are essentially cards that you install into your router, once installed you connect an Async cable to one of the ports on the card which normally gives you 8 console cables and are normally labelled 1 through 8. You connect all of the cables to the devices you need (even non-Cisco devices) whether switches, routers or firewalls, they will usually work. The real m........

Huion and Wacom Tablets How To Install in Linux Mint / Ubuntu and make the stylus work properly

It took a lot of fiddling to make a Huion Kamvas 13 Pro work in Linux but it simple once you know what to do. Don't bother searching as it is unlkely there is a guide out there that will actually make your tablet work. It mainly comes down to the fact that the hid_uclogic kernel module is buggy or doesn't support MANYof these wacom based/Huion tablets properly. What was happening with me is that Ihad the Kamvas 13 Huion setup as a secondary screen/monitor.&nb........

How To Replace Audio Track of Video using ffmpeg

A very common use case is that you don't want to waste time using a video editor that requires you to open it up and manually import the video clip and audio clip, then manually delete the old audio track and import the video and new audio. That's too much work and time since we don't want to go through the hassle. ffmpeg is our solution, all we have to do is specify 3 variables and we're done! -i Windows2019-Server-Noaudio.mp4 is our in........

?? Question Marks for time, permissions and size of a file?

-?????????? ? ? ? ? ? shadow ----------. 1 root root 748 Jul 10 04:35 shadow- cat: shadow: Input/output error If you see this you are probably in big trouble, it could be a physical error or if it's a VM image that it is corrupted due to a physical error on the underlying disk/array/NAS or it could a........

How To Get Started on Ubuntu with gpt-2 OpenAI Text Prediction

apt install software-properties-common add-apt-repository ppa:deadsnakes/ppa apt update apt install python3-pip apt install python3.7 curl gnupg python3.7-dev git ln -s /usr/bin/python3.7 /usr/bin/python3 pip3 install numpy keras_preprocessing curl https://bazel.build/bazel-release.pub.gpg | sudo apt-key add - echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel........

MariaDB / MySQL Reset Root Forgotten Password on Centos 7

mysql reset root password. Oops I can't remember my MySQL root password! [root@centos7test etc]# mysql -u root -p Enter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) First we need to stop mariadb: systemctl stop mariadb Now we need to restart it with skip-grant-tables whic........

MySQL Bash Query to pipe input directly without using heredoc trick

Most of us know the heredoc method but what if you need a basic query done repeatedly and manually while working from bash? It is a pain to manually type mysql and login each time. With this command below you can semi-automate those queries: echo "use somedb; select * from auctions" | mysql -u root --password="yourpassword" Just modify the above to suit your needs and you can add more queries by adding a sem........

Cisco Unified Communications Manager / CUCM IP 8.6,10,12 Install Error Solution

Install Errors on Version 12: This error happened on QEMU emulator version 2.11.1 pve-qemu-kvm_2.11.1-5 on Proxmox/Debian but installing on QEMU.12 on Centos 6 did not produce the error. *Update it is not related to the OS or QEMU version. This happened in Centos 6 too after a second install. What really causes this even though you successfully install........

Cisco Unified Communications Manager 12 Install Errors on Proxmox/KVM

The strange thing is that usually the first install or two will work on any new machine but then it suddenly won't. I had this experience on QEMU 2.13 on a different machine. There is something finicky or buggy about the CUCM installer even when choosing the same virtual hardware specs. qemu-kvm command: /usr/libexec/qemu-kvm -version QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2-2.506.el6_10.1), Copyright (c) 2003-2008 Fabrice Bellard ........

iptables linux firewall recommended rules for public computing

Whether you are at work, at the coffee shop or on the public internet here are some basic but effective rules for iptables that lock things down (eg. no one can SMB or SSH to you or really anything): # Generated by iptables-save v1.4.21 on Fri Dec 14 14:00:08 2018 *nat :PREROUTING ACCEPT [160:19844] :INPUT ACCEPT [4:357] :OUTPUT ACCEPT [2955:182236] :POSTROUTING ACCEPT [2955:182236] COMMIT # Completed on Fri Dec 14........

iptables how to log ALL dropped incoming packets

A lot of people just have a -j DROP to drop all unwanted traffic or traffic not explicitly allowed but there is a better solution if you want real and proper logging: Here is another example of more advanced iptables rules. Take an example iptables rules file -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -i eth1 -p icmp -j ACCEPT........

Linux use growisofs to burn a larger file on a BD-R / Bluray Disc

growisofs -Z /dev/sr0 critical.tar.gz.gpg Executing 'genisoimage critical.tar.gz.gpg | builtin_dd of=/dev/sr0 obs=32k seek=0' I: -input-charset not specified, using utf-8 (detected in locale settings) File critical.tar.gz.gpg is larger than 4GiB-1. -allow-limited-size was not specified. There is no way do represent this file size. Aborting. :-( write failed: Input/output error #remember to us........

DRBD Errors Caused By Physical Corruption

In a RAID array I had a have periodically lost a drive here and there over the past several months. Iwas always able to readd and resync without losing data. However at some point it looks like some minor corruption happened and this makes DRBD unhappy. Using fsck did not help either. Dec 19 06:01:45 storageboxtest4 kernel: [19005.945890] EXT3-fs error (device drbd0): ext3_get_inode_loc: unable to read inode block - inode=22184379........

What is /dev/pts and why do we need it in Linux?

A quick check in /dev/pts shows a lot of entries but what are they for?: ls /dev/pts 0 10 12 14 16 18 2 21 23 25 27 29 30 32 4 6 8 ptmx 1 11 13 15 17 19 20 22 24 26 28 3 31 33 5 7 9 Basically they are pseudo-termi........

genisoimage errors with long filenames and deep directory structures

You'll have to violate the iso9660 standards but it is necessary if you want to preserve your filesystem and filenames and shouldn't be an issue as long as you are using a modern OS like Linux. genisoimage -o Backup-Myfiles.iso -r -J -joliet-long /some/path/ You will get errors like below (even enabling joliet-long didn't help) genisoimage: Error: /some/filename.pdf have the same Joliet name Joliet tree sort failed. The -joliet-lo........

gvfs mount in /run/user cannot be accessed or displayed wrong permissions Error: Location is already mounted

You get errors like below and see you have all question marks for the permissions if you go to /run/user/1000/gvfs If you try to access the mounted share such as anything mounted as gvfs like an SSH share in your file manager you may get an error like this. It generally means an interruption in communication or a fault with gvfsd has caused it. Solutio........

zenity popup messages, windows, dialogs, error messages calendars and more howto on Gnome Linux including Ubuntu, Linux Mint, Centos and more

zenity is a nice utility as part of the gnome window manager that allows you to script from bash and retrieve the input from the user. It could also be helpful in just notifying a user when they login with a popup window. I'll give an overview of what's available with zenity: Application Options: --calendar Display calendar dialog --entry Display tex........

wodim / cdrecord error cannot burn DVD or BDR .iso Errno: 5 (Input/output error), write_g1 scsi sendcmd: no error

dvd+rw-mediainfo /dev/sr0 INQUIRY: [ASUS ][BW-16D1HT ][3.00] GET [CURRENT] CONFIGURATION: Mounted Media: 11h, DVD-R Sequential Media ID: RITEKF1&n........

iptables guide and examples and howto

iptables allow port 22 example Of course change --dport and -s to suit your needs #allow certain IP to access port 22 iptables -A INPUT -p tcp -m tcp --dport 22 -s 192.168.1.0/24 -j ACCEPT # block others iptables -A INPUT -p tcp --dport 22 -j DROP........

Cannot create gradle for conversations

The main issue is it looks like Java is not configured to accept the invalid ssl cert that is coming from the download location. Exception in thread "main" java.lang.RuntimeException: javax.net.ssl.SSLException: java.security.ProviderException: java.security.InvalidKeyException: EC parameters error export ANDROID_HOME=/home/user/Downloads/tools/ Conversations-master$ ./gradlew Downloading https://services.gradle.org/distributions/grad........

Mozilla Firefox Address Bar History Not Working places.sqlite corruption solution database repair

Here is the only solution Ifound that works in Firefox: *Note you could basically just copy all of the commands in bold (the rest just shows the output) Install sqlite3 sqlite3 places.sqlite sqlite> .clone places.sqlite-fixed moz_places... done moz_historyvisits... done moz_inputhistory..........

Intel NUC J3455 Linux Kernel freeze slowness 4.4.98 errors

It looks like this has something to do with APIC but I am not sure. I have similar CPUs with a different MB and BIOS that work fine on the same type of kernel. A lot of time the issue is because of the C-step setting in the BIOS. The same thing happened on the 2.6 kernel with Centos 6 but this is a homebrew 4.4 kernel soI am not sure why it is happening when even Centos 7 (3.2) kernel works OK. Solution - It comes down to the BIOS set........

Linux input/output error invalid program cannot read data on some CD-Rs and DVD-Rs on ASUS BW-16D1HT

I've never seen this before in all of my years. Ihave some very old CDs and DVDs 12-15 years old that seem not to work in this BD-R/DVD-R/CD-R Asus drive. The discs are fine actually and ironically they even work fine on a normal LG USB based BD-R drive! Here are the errors in Linux: [2914936.884924] attempt to access beyond end of device [2914936.884927] loop1: rw=0, want=730424, limit=688384 [2914954.556873] attempt to........

bash find line and replace howto

First find the line number: awk '/what you are searching for/{ print NR; exit }' input-file 86 Now use sed to replace it: sed -i 86s/.*/"your replacement text"/ $file Here is a full sample script to automate it: file=some/f........

ffmpeg vidstab to stabilize video

I'm having trouble making it work on very shaky video the result seems kind of warped/blurry/fish eye like and not as good as some other examples I've seen: ffmpeg -i MVI_1285.MOV -vf vidstabdetect=shakiness=10:accuracy=15 -f null MVI_1285.trf ffmpeg -i MVI_1285.MOV -vf vidstabtransform=smoothing=30:input="transforms.trf" MVI_1285.MOV.mp4 I've played around with the shakiness, accuracy etc.. but not the smoothing part.........

ffmpeg how to watermark and concatenate in one command

If you were in my boat you were frustrated that you had to double encode, eg. one separate encode for watermark and a separate from concat and it's not easy to figure out this with ffmpeg on your own. However it is a nice way to save time! ffmpeg -i file1.mp4 -i file2.mp4 -i file3.mp4 -i watermark.png -filter_complex "[0:v]setpts=PTS-STARTPTS[v0]; [1:v]setpts=PTS-STARTPTS[v1]; [2:v]setpts=PTS-STARTPTS[v2]; [v0][0:a][v1][1:a][v2][2:a]concat=n=3:v=1:a=1[v][aout]; [v][3:........

ffmpeg trouble concatenating similar but different files

When things go wrong your video is basically unplayable or the first video plays fine and then freezes when moving on to the next. Generally if both videos weren't produced with the exact 100% same settings you will have issues. You can try the basic concat but it often won't work right. Solution for me: My example uses 3 videos in total so "n=3" and a=1 to include audio. ffmpeg -threads 12 -i file1.mp4 -........

Linux Mint Intel Screen Tearing Horizontal Line Solution Fix Intel i915 Intel HD 4400 GPU Debian / Ubuntu

sudo mkdir -p /etc/X11/xorg.conf.d/ sudo vi /etc/X11/xorg.conf.d/20-intel.conf On newer Ubuntu / Mint / Debian systems the file would go in: /usr/share/X11/xorg.conf.d/20-intel.conf Type "i" and enter the following: Section "Device" Identifier "Intel Graphics" Driver&n........

Track 01: 34 of 1726 MB written (fifo 100%) [buf 99%] 3.6x.Errno: 5 (Input/output error), write_g1 scsi sendcmd: cmd timeout after 1.897 (40) s CDB: 2A 00 00 00 44 A9 00 00 1F 00 resid: 6144 cmd finished after 1.897s timeout 40s write track da

These errors believe it or not are simply because of not being the root user or running with sudo! However if you didn't know to try as root you'd think there was a problem with your burner or disc Essentially it looks like without root you cannot send the required scsi commands to continue writing. Ithink cdrecord should have built-in tests or safeguards to see if it has the permissions to run the required commands. I guess for more advanced users the idea is simila........

PayPal Subscription Howto Creation Automatic Payments Manual

An easy way to pay companies and friends/family since PayPal does not have an option when sending money to make it a subscription: "business" = The e-mail or PayPal ID of the person/organization to pay to. a3 The recurring amount "eg. 115" will be 115 USD p3 The time period (eg. 2) t3 Unit of time period m=monthly,w=weekly,y=yearly item_name = "the note/product service reason you are paying ha........

Centos extremely secure iptables setup

If you want to make sure only a certain IP can access your server for any service or protocol here is a way to do it (just be sure you have access to the IP(s) mentioned or you will be locked out). iptables -F iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A INPUT -p tcp -s IP.IP.IP.IP -j ACCEPT iptables -A INPUT -j DROP serv........

Linux How To Recover Partition Table from Kernel and Restore Centos/Debian etc..

We've all done this at some point, you work on the wrong shell window and this was my first time making this mistake but I deleted a partition table in fdisk, recreated it and saved it with "wq" and even ran partprobe! If you haven't rebooted yet then you can still recover your partition table, otherwise you're in big trouble. Fortunately since it was a live system and in use the kernel still had to use the old table like below:........

dir2slideshow Centos rpm requirements

yum -y install dvdauthor ffmpeg mjpegtools sox bc rpm -ivh dvd-slideshow-0.8.4-2.noarch.rpm Preparing... ########################################### [100%] 1:dvd-slideshow ########################################### [100%] /usr/bin/dir2slideshow: line 553: bc: command not f........

PayPal subscriptions automatically cancelling after creation of profile

There is a weird quirk with how this works, but there is a variable called "src" that defaults to 0 or disabled if not specified as 1. The default 0 means not to recur billing on a subscription. It's too bad it's not more obvious anywhere nor is there an explanation or warning during payment or after to both the seller and buyer. Here's a proper subscription code example that does recur and does not cancel........

2CO/2Checkout how to create recurring payment subscription button dynamically

It was hard to find this as I find most online payment processors don't just put the basic information in plain view. Remember to set your sid (your seller id). The below can easily be turned into a scripted PHP template to integrate into your own custom or existing payment solution. http://help.2checkout.com/articles/How_to/How-to-Sell-Recurring-Products-with-2Checkout/........

PayPal Convert BuyNow Button to Plain HTML Link

Say if you have a form/button like this: ........

SolusVM error error: Failed to create domain from /home/kvm/kvm101/kvm101.xml error: cannot open file '/dev//dev/kvmcontainer/kvm101_img': No such file or directory

error: Failed to create domain from /home/kvm/kvm101/kvm101.xml error: cannot open file '/dev//dev/kvmcontainer/kvm101_img': No such file or directory This is caused by what we consider a quark in SolusVMthat Ihelped a client with. SolusVMhas as config for the "LVMvolume name" and does not enforce any convention. Naturally most technical people would use the actual path eg "/dev/kvmcontainer". However th........

OpenVZ mismatched kernel and dev when compiling.

./configure ./configure: line 91: cd: /lib/modules/2.6.32-042stab084.25/build: No such file or directory Error: kernel version not found. Please make sure your kernel is configured. dr-xr-xr-x. 4 root root 4096 Feb 21 06:13 .. lrwxrwxrwx 1 root root 45 Feb 21 06:13 build -> ../../../usr/src/kernels/2.6.32-042stab084.25 drwxr-xr-x 2 root root 4096 Feb 12 20........

Wordpress Custom Menu Limit Fix/Solution

This is usually solved by two variables alone: max_input_vars=5000 memory_limit=256M Now you should be able to have unlimited amounts of custom menus in Wordpress.........

MySQL Allows blank user with no password to login

I just realized I have some blank users which I deleted butI can still login to this dummy account without a password for some reason. mysql -u -p Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 5 Server version: 5.1.69 Source distribution Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation an........

Dell Perc 6/i SATA benchmarks without battery

The results are not bad, the Hitachi performs the same as it does in a SATA2 motherboard. However, the 2TB is much different, on a similar 2TB Toshiba I get about 198MB/s on a different motherboard vs the 2TB Hitachi which should produce similar results. This Dell Perc 6/i is on a PCI x8 riser card and is connected to a 12-port backplane. Adapter #0 Enclosure Device ID: 32 Slot Number: 0 Enclosure position: N/A De........

Dell Perci 6/i Firmware Upgrade Guide Tutorial

One thing to remember is that you need MegaCli to do the flashing. You also need the correct file,I tried at least 2 different Perc 6 firmwares from Dell that kept getting rejected as corrupt by MegaCli(they were really the wrong version). I have an external PCI-E Dell 6 Perc/I butI chose images from the 'Integrated" on motherboard version as it was allI could find. They are different, and below is my first time finding success.........

LSI MegaRAID Adventures, Guide and HowTo

LSi Megaraid At first it was configured as a RAID 0, then I deleted the Virtual Disk Group. I thought both drives would be shown and detected in Linux as sda and sdb but it actually shows nothing. To make them work you have to hit Ctrl+R before the system boots (when prompted) and create a Virtual Disk Group. In my case I created each one as RAID 0 (with a single drive only) as I just wanted JBOD but there is no such option or default in these Dell Pe........

Ubuntu/Linux disable extra Mouse Buttons Microsoft Comfort Mouse 4500

I find it very annoying that this mouse has buttons on the side where you grip it and the left one goes back in the browser and the right one goes forward. Imagine if you're filling out a form and hit it, most forms/websites have no protection against it. Source: http://ubuntuforums.org/showthread.php?t=2065400 Here's how I fixed it with xinput, it's too bad there's no good standard GUI to........

Startech SV1107IPEXT KVM/IP Review

Let's keep this simple, it's horrible, not only is the picture quality horrible (it's not a big deal) but the keyboard input is an issue. You have to type slowly, lightly and carefully otherwise 1-keystroke could end up being dozens of keystrokes. It's also a confusing unit for many datacenter techs, I've seen these units hooked up wrong and the instructions themselves aren't clear. I had to resort to shipping one to my office and take my phone pictures of the setup for th........

bash script remove non-printable special characters/white space

In bash you test like this for problems that can be caused by non-printable characters since if you don't know how to identify it because it basically breaks your script. echo "url=$url" should print something like this normally if you have properly formatted input/text: url=::http://someaddress.com:: But if you have some weird hidden characters (not visible in a text editor of any sort you'll get something like this ::l=::http://s........

iptables block torrents/torrenting

This is a very basic method and won't work in all cases but will reduce the chance of torrenting/abuse by your server users. iptables -A INPUT -p tcp --destination-port 6881:6999 -j REJECT iptables -A OUTPUT -p tcp --source-port 6881:6999 -j REJECT........

How To Burn ISO Image using cdrtools/dvdrtools for Linux/Unix Ubuntu/Debian/RHEL/Centos etc..

It really is as simple as: cdrecord -v dev=/dev/sr0 pathtoyourisoimage.iso -v is for verbose, I prefer it but if you don't you won't see as much output like below (I like to know the details and exactly what's happening) dev=/dev/sr0 specifies the device name of your burner (they say not to use it and to specify some weird annoying device string but using the raw /dev has always worked for me and is how it should have been implemented from the start IMHO)........

gocr - free Linux OCR (Optical Character Recognition) conversion tool

gocr works great and it's simple, just invoke it like so: gocr filename.png The output will be printed to the screen. My only complaint/concern is that even with standard terminal output (not scanned) from a printscreen, gocr does make mistakes by inserting extra spaces where they don't belong, mistaking letters for numbers etc.. but it's definitely enough to be readable and figure out what you're looking at. I haven't tested yet with scanned input........

Linux Kernel Panic Messages - Symptoms of bad RAM module/stick

These were caused by a bad stick of Corsair RAM [] free_hot_cold_page+0xfc/0x150 [] __pagevec_free+0x14/0x1a [] release_pages+0x127/0x12f [] __pagevec_release+0x15/0x1d [] __invalid_mapping_pages+0x120/0x156 [........

How To Test If Your Hard Drive Is Good/Signs of dying hard drive

I like dd, although it only reads it, usually a read test of the entire disk will uncover if your hard drive is bad in some parts. This is a good thing to do at least once a month, a lot of times bizarre program behavior, laginess and crashing/unnmounting problems etc.. are due to a failing disc and SMART won't know it or indicate a problem: We must also remember there's never a guarantee, I've found that ever since we moved to larger and more platters per drive with 1TB drives........

Enable SPAMASSASSIN on Postfix in 5 minutes

Centos 5 Postfix and SPAMASSASSIN Tutorial yum install spamassassin chkconfig spamassassin on vi /etc/mail/spamassassin/local.cf ############## #required_hits 5 #report_safe 0 #rewrite_header Subject [SPAM] #5 is the least restrictive (means only the most obvious SPAM is caught. 0 is obviously the most restrictive/sensitive and would have lots of false positives require........

Ubuntu 9.04 Crash

CPU/Kernel/MB/RAID problem? Jan 5 12:45:05 testbox kernel: [653298.890004] BUG: soft lockup - CPU#0 stuck for 61s! [hal-acl-tool:4168] Jan 5 12:45:05 testbox kernel: [653298.890005] Modules linked in: vmnet vmci vmmon binfmt_misc drbd video output input_polldev ocfs2_stackglue ocfs2_dlmfs ocfs2_dlm ocfs2_nodemanager configfs k8temp hwmon_vid lp snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi........

WD EARS/Green 2TB Cannot Disable Power Saving/Head Parking with hdparm

hdparm -B 255 /dev/sdb /dev/sdb: setting Advanced Power Management level to disabled HDIO_DRIVE_CMD failed: Input/output error The one thing you can do though is to set hdparm spindown time lower (it doesn't seem to work that well). -S set standby (spindown) timeout hdparm -S 251 /dev/sda /dev/sda: setti........

mencoder Linux CLI video editing how to encode video file into xvid and split by time into multiple parts

Mencoder is great, you can throw anything at it, including video files from your camera and have it encode into xvid or almost any other format. In my case I took 640x480 video from my Canon and reduced the size by 1/3 with the options below (there are many other options that you can read about in the manual but I like to keep it simple). Mencoder Encode mencoder -ovc xvid -oac mp3lame -xvidencopts fixed_quant=4 -o ........

tar gzip: stdout: File too large - Error Size Limit on Large file > 17GB

The folder I was trying to archive is about 72GB, but much like rsync at about 17GB it chokes because of the filesize. What's with so many common and essential Linux tools having such limitations? I guess it is likely that the authors never wrote their code with the idea that files would be so large but it's still very annoying. It's important to stay on top of these limitations on production servers because I didn't realize what happened until I checked the file with "........

Javascript Get a specified element using getElementById()

Javascript Get a specified element using getElementById()Great, it produces the value for whatever "id" is passed to the function. http://www.java2s.com/Code/JavaScript/Development/GetaspecifiedelementusinggetElementById.htm [code:1:1287ede953] function getElement(){ var x=document.getElementById("myHead........

JavasScript how to set or write value in id tag

JavasScript how to set or write value in id tagbla I need to set a value inside that DIV tag using Javascript, how would I do it?Doesn't work for me: [quote:c6b5f693a5]Warning: Element referenced by ID/NAME in the global scope. Use W3C standard document.getElementById() instead. Source File: http://hosting.com/vps-order.html Line: 19[/quote:c6b5f693a5] [code:1:c6b5f693a5]........

The New Chips on the Block

The New Chips on the BlockThe New Chips on the Block By Bruce Gain Story location: http://www.wired.com/news/infostructure/0,1377,67795,00.html 02:00 AM Jun. 13, 2005 PT We have embarked upon a new era in x86 PC computing -- so say chip giants AMD and Intel following their launches of dual-core PC processors. So how will dual-core processing change your PC computing experience? Our FAQ should help you decide whether or when you sho........

Debian/Ubuntu/Kubuntu Bash/Console/Terminal/Putty Home and End Keys Don't Work or Produce a ~

This is a very weird, annoying and bizarre quirk with many distributions, especially Debian. The home and end keys don't work, but it's a simple fix as long as you found this article :) You just have to edit /etc/inputrc: Find the commented lines as shown below: # "e[1~": beginning-of-line # "e[4~": end-of-line *If you can't find the above, just copy and paste the code below into your inputrc, it will en........

Linux/Unix Open SSH Login Without Password Key Exchange including Debian, Redhat, Fedora, Ubuntu, BSD etc..

In those 4 simple commands you can setup mutual key exchange between two sshservers by using a single login shell session and single window. *Just change the IP address examples of (10.10.0.2) to the target of your mutual key exchange. It doesn't matter if the server is on a LANor WAN(well unless the server is behind a firewall and you cannot SSHinto it).........