/ - rtt - IT Resource

  • 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


    The folder contents could not be displayed Backend currently unmounting drwx------ 10 userhere group  260 Aug 23 19:40 .. ??????????  ? ?   ?      ?            ? sftp:host=192.168.8.80,user=adhoc ls: cannot access 'sftp:host=192.168.8.80,user=adoc': Input/output error $ ps aux|grep fuse one       253........
  • 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 I found 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 so I 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.  I have 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


    sudo mkdir -p /etc/X11/xorg.conf.d/ sudo vi /etc/X11/xorg.conf.d/20-intel.conf   Type "i" and enter the following: Section "Device"   Identifier      "Intel Graphics"   Driver          "intel"   Option          &........
  • 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.  I think 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


    <p>There is a weird quirk with how this works, but there is a variable called &quot;src&quot; that defaults to 0 or disabled if not specified as 1.</p> <p>The default 0 means not to recur billing on a subscription.&nbsp; 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.</p> <p><strong>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:          <form method="post" action="https://www.paypal.com/cgi-bin/webscr">                 <input type="hidden" value="_s-xclick" name="cmd" /> <input type="hidden" value="THEBUTTONID" name="hosted_button_id&quo........
  • 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 SolusVM that I helped a client with. SolusVM has as config for the "LVM volume 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 but I 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 but I chose images from the 'Integrated" on motherboard version as it was all I 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 [<c0466769>] free_hot_cold_page+0xfc/0x150 [<c04667d1>] __pagevec_free+0x14/0x1a [<c0468c6b>] release_pages+0x127/0x12f [<c04692d1>] __pagevec_release+0x15/0x1d [<c04697db>] __invalid_mapping_pages+0x120/0x156 [<c046981........
  • 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 <filename.avi> -ovc xvid -oac mp3lame -xvidencopts fixed_quant=4 -o <output.avi>........
  • 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] <html> <head> <script type="text/javascript"> 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 tag<div id="price">bla</div> 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 LAN or WAN (well unless the server is behind a firewall and you cannot SSH into it).........
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