system installation – Problems with the install of Ubuntu on a windows machine

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Encoding problems in drush 7 running on Windows

I am not very familiar with PHP, Drupal and drush but I inherited a site running on Windows Server 2019 (in the process of being migrated from Ubuntu). When I want to download some webforms using drush wfx, special characters like German “Umlaute” ä, ö and ü in the webform contents are not correctly displayed.

I am running Drupal 7.81 und using drush 7.0.0. I also tried to specifially set the encoding to UTF-8 in the config file drushrc.php (even though the description in the file says, it should not be necessary because drush will use UTF-8 anyway). In the browser, the characters in the webform show up correctly.

The database character set is utf8.

Any idea what to try and how to troubleshoot?

PS > Get-CimInstance -ClassName Win32_OperatingSystem | fl Caption,Version

Caption : Microsoft Windows Server 2019 Standard
Version : 10.0.17763
PS C:xamppmysqlbin> .mysql.exe -uroot
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MariaDB connection id is 7405
Server version: 10.1.38-MariaDB binary distribution

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB ((none))> SELECT @@character_set_database,@@collation_database;
| @@character_set_database | @@collation_database |
| latin1                   | latin1_swedish_ci    |
1 row in set (0.00 sec)

MariaDB ((none))> USE drupal;
Database changed
MariaDB (drupal)> SELECT @@character_set_database,@@collation_database;
| @@character_set_database | @@collation_database |
| utf8                     | utf8_general_ci      |
1 row in set (0.00 sec)
PS C:xampphtdocsonboarding> drush version
 Drush Version   :  7.0.0

PS C:xampphtdocsonboarding> drush status
 Drupal version                  :  7.81
 Site URI                        :  http://default
 Database driver                 :  mysql
 Database hostname               :  localhost
 Database port                   :
 Database username               :  drupal
 Database name                   :  drupal
 Drupal bootstrap                :  Successful
 Drupal user                     :
 Default theme                   :  garland
 Administration theme            :  seven
 PHP executable                  :  php.exe
 PHP configuration               :  C:drushphpphp.ini
 PHP OS                          :  WINNT
 Drush script                    :  C:drushvendordrushdrushdrush.php
 Drush version                   :  7.0.0
 Drush temp directory            :  C:Users%USERNAME%AppDataLocalTemp13
 Drush configuration             :  C:ProgramDatadrushetcdrushdrushrc.php
 Drush alias files               :
 Install profile                 :  standard
 Drupal root                     :  C:xampphtdocsonboarding
 Site path                       :  sites/default
 File directory path             :  sites/default/files
 Temporary file directory path   :  /tmp

php – Problems with XML digest value (for The Danish Health Data Authority)

I want to create some XML which has to contain a digest value, i.e., a BASE64 encoded hash value of some of the XML in canonical (C14N) form, but the receiver does not accept the value my code calculates nor the XML when done according to the (faulty) documentation (and the calculations match the expected value) – unless I make a dirty hack which doesn’t make sense to me.

I fortunately have access to an existing system which allows me to compare what the receiver expects and there I could see that my calculation gave another result than the existing system calculated when my code created the same XML as the existing system but I realized (after reading the (faulty) documentation) that the XML were supposed to have some extra namespace attributes – and suddenly my code calculated the correct digest value!?!

I.e., I can calculate the correct digest value by creating the XML in two passes! One with the incorrect XML (as documented in the (faulty) documentation) and store the calculated value and then the second version where the code insert the calculated value from the first pass.

Does this ring a bell for anyone? Anyone working with the Danish Health Data Authority?

I have the following helper functions:

function createElement(DOMDocument $xml, DOMNode /*DOMDocument&DOMElement*/ $parent, string $name) : DOMElement {
    $node = $xml->createElement($name) or die("<span class="fail">createElement($name) failed</span>");
    return $parent->appendChild($node);

function createElementNS(DOMDocument $xml, DOMNode /*DOMDocument&DOMElement*/ $parent, string $ns, string $name) : DOMElement {
    $node = $xml->createElementNS($ns, $name) or die("<span class="fail">createElementNS(..., $ns, $name) failed</span>");
    return $parent->appendChild($node);

function createAttribute(DOMDocument $xml, DOMElement $parent, string $name, string $value) : DOMAttr {
    $attribute = $xml->createAttribute($name) or die("<span class="fail">createAttribute(..., $name, $value) failed</span>");
    $attribute->value = $value;
    return $parent->appendChild($attribute);

function createAttributeNS(DOMDocument $xml, DOMElement $parent, string $name, string $value) : DOMAttr {
    $attribute = $xml->createAttribute($name) or die("<span class="fail">createAttribute{NS}(..., $name, $value) failed</span>");
    $attribute->value = $value;
    return $parent->appendChild($attribute);

function createTextNode(DOMDocument $xml, DOMElement $parent, string $text) : DOMText {
    $text_node = $xml->createTextNode($text) or die("<span class="fail">createTextNode($text) failed</span>");
    return $parent->appendChild($text_node);

and excerpts of the code look like this

$hack_pass = 0;

while (++$hack_pass <= 2) {
    $xml = new DOMDocument('1.0', 'UTF-8');

    $xml_soapenv_envelope = createElementNS($xml, $xml, '', 'soapenv:Envelope');
    createAttributeNS($xml, $xml_soapenv_envelope, 'xmlns:ds', '');
    createAttribute($xml, $xml_soapenv_envelope, 'id', 'Envelope');

    $xml_soapenv_header = createElement($xml, $xml_soapenv_envelope, 'soapenv:Header');
    $xml_wsse_security = createElement($xml, $xml_soapenv_header, 'wsse:Security');
    $xml_wsu_timestamp = createElement($xml, $xml_wsse_security, 'wsu:Timestamp');
    $xml_wsu_created = createElement($xml, $xml_wsu_timestamp, 'wsu:Created');
    createTextNode($xml, $xml_wsu_created, $created);

    if ($hack_pass == 1) {
        $xml_saml_assertion = createElementNS($xml, $xml_wsse_security, 'urn:oasis:names:tc:SAML:2.0:assertion', 'saml:Assertion');
    } else {
        $xml_saml_assertion = createElement($xml, $xml_wsse_security, 'saml:Assertion'); // Final XML
    if ($hack_pass < 2) {
        $c14n = $xml_saml_assertion->C14N(TRUE);
        $DigestValue = base64_encode(hash('sha1', $c14n, TRUE));

Chain rule problems

Given- f'(x)= $e^sqrt x$ I want to find f'(x²) I know the answer is $e^x$ but there is no explaination given so someone provide me proper expalination.
Thanks a ton.

Research on exact-cover problem and graph theory for NP-complete problems?

Sorry for the vagueness, but I’m trying to study the latest progress on the exact cover problem and using graphs for NP-complete problems. Googling around has not been very helpful. I understand the basics but I can’t find a key journal in this area or where to look online. Any references would be greatly appreciated!

filesystems – LVM: Problems in adding disk to an existing Logical volume

I have a disk under a Logical Volume.

$ lvdisplay
  --- Logical volume ---
  LV Path                /dev/vg_prod/lv_prod
  LV Name                lv_prod
  VG Name                vg_prod
  LV UUID                mXj3Qv-t0GK-4idW-mRBA-17Nb-PSPK-Roulf3
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                <3.64 TiB
  Current LE             953797
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1

Now, I want to add a new disk to extend the volume. The disk is attached through the USB interface.

$ fdisk -l /dev/sdg
Disk /dev/sdg: 3.65 TiB, 4000752599040 bytes, 7813969920 sectors
Disk model: Game Drive
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

When I try to add it to extend the volume, I get the error.

$ vgextend vg_prod /dev/sdg
Devices have inconsistent logical block sizes (4096 and 512).

So I started to change the logical sector size for /dev/sdg to 4096.

$ fdisk -b 4096 /dev/sdg

When I print the partition table in fdisk, I do see the logical sector size as 4096.

Welcome to fdisk (util-linux 2.34).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xf4a7867a.

Command (m for help): p
Disk /dev/sdg: 3.65 TiB, 4000752599040 bytes, 976746240 sectors
Disk model: Game Drive
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0xf4a7867a

When I create a partition, write changes, and list. It goes back to showing 512 as logical sector size.

Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1): 1
First sector (256-976746239, default 256):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (256-976746239, default 976746239):

Created a new partition 1 of type 'Linux' and of size 3.7 TiB.

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
$ sudo fdisk -l /dev/sdg

Disk /dev/sdg: 3.65 TiB, 4000752599040 bytes, 7813969920 sectors
Disk model: Game Drive
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0xf4a7867a

Device     Boot Start       End   Sectors   Size Id Type
/dev/sdg1         256 976746239 976745984 465.8G 83 Linux

Is there a way to change my disk to have logical sector size 4096 so I could add it to the existing storage that I already have?

windows 10 – Problems printing to a plotter

I have an excel sheet that goes from A75 – E75. Every time I print to the plotter it comes out super small. I have tried everything from changing margin size, ratio, paper size, scaling. I have exported to a pdf then tried printing that, nothing works.

I thought that maybe the sheet is simply just too big to be able to fit on a single page, but from what I understand about plotters, and from what many people have told me, that is not true.

Does anyone have any suggestions? I have tried everything I can possibly think of and nothing seems to work.

networking – Intermittent problems connecting to wifi router

I am hoping for some help with troubleshooting steps on this one. I am having intermittent problems connecting to the internet on multiple laptops. I ran ipconfig and everything looks okay. I did a ping to and I got intermittent request timeouts. I then ran ping against my default gateway which is also the wifi router and got a similar problem. so it appears the problem is with the router. I tried resetting it by pulling the power but I am still having the same problem. I was hoping for some help with any next steps for troubleshooting this.

Here is a sample output of my ping to my router:

Reply from bytes=32 time=7ms TTL=64
Reply from bytes=32 time=7ms TTL=64
Reply from bytes=32 time=7ms TTL=64
Request timed out.
Reply from bytes=32 time=3196ms TTL=64
Reply from bytes=32 time=1817ms TTL=64
Reply from bytes=32 time=7ms TTL=64
Reply from bytes=32 time=470ms TTL=64
Reply from bytes=32 time=7ms TTL=64
Reply from bytes=32 time=198ms TTL=64
Reply from bytes=32 time=73ms TTL=64
Reply from bytes=32 time=8ms TTL=64
Request timed out.
Reply from bytes=32 time=16ms TTL=64
Reply from bytes=32 time=278ms TTL=64
Reply from bytes=32 time=265ms TTL=64
Reply from bytes=32 time=163ms TTL=64
Request timed out.
Request timed out.
Reply from bytes=32 time=7ms TTL=64
Reply from bytes=32 time=271ms TTL=64
Reply from bytes=32 time=3020ms TTL=64
Reply from bytes=32 time=7ms TTL=64
Reply from bytes=32 time=7ms TTL=64

You can see that it is good most of the time, but then it will get really slow, up to 3+ seconds, and then it will timeout, then be good again.

replication – How Can I Find the Problems Occurred on MySQL-MariadbDB Systems?

I have built a three-node galera cluster, so it is a Master-Master replication structure. But sometimes the first node goes down and I can’t find the problem causing this. I am only looking at /var/log/syslog files. Where should I look to find the problems? Is there other log files I can look on production environment? Where the database admins looks for db errors?