Ubuntu

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I have Ubuntu 18.04 LTS (64-bit) laptop.  Was it shipped with anti-virus software?  If not, what anti-virus do I need to install?

How to run full anti-virus scan?
0
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I have a Linux server (Ubuntu 14.04.5 LTS) on my internal network with a private IP address.  I am trying to SSH to the Linux server from the internet. I have configured my firewall to forward all traffic, sent to a public IP address, to the private address on the Linux server. When I do a packet capture on the port that the server is connected to, and use Wireshark to view the packets, I can see the packets from my internet workstation getting to the port, but the server seems to be rejecting them. If I SSH internally I can connect fine, so I know SSH works.

It appears that the server doesn't recognize the packet going to the public IP address. As though the server is saying, that packet isn't coming to me because it was sent to another IP address.

Any thoughts on that? Could there be a setting in Ubuntu that would reject packets bound for a different IP than what the NIC has?
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I have an issue to create a domain for my customer. they do not have one. They all using Linux (ubuntu , redhat, centos,...) as client, no windows or ms product.
What is the best to choose?  
Linux domain (active directory) not have a ldap (or not easy to work as backend ldap).
Redhat ipa (centos) is a ldap but not working as active directory.
Windows domain (they do not want) and it's problem to join linux server to active directory.
What you suggest as expert?
1
We have a really old physical Ubuntu server that no longer boots up into the OS.  The errors on boot up are:

"Volume group "volgrp01" not found"
"mount: could not find filesystem '/dev/root'"

which eventually result in a Kernel panic.

The system uses software RAID 1 with 2 physical disks
/dev/md0 uses sda2 and sdb2


The array md0 contains logical volumes for /root, /home, /opt, /tmp

The md0 array doesn’t appear to be assembled/started on boot (I think this is the main issue)

I can boot up to a Linux Live CD and assemble the md0 array and everything looks fine.  It previously was degraded and reported sdb2 as missing….but I was able to add it back to the array and let it rebuild

/boot isn’t on the software RAID, but is on /dev/sda1 and /dev/sdb1
 
I’m not really sure how to get the md0 RAID array to be assembled/started on boot, but I think if I can get that figured out it will fix the server.  I’m not sure if the problem is with something like Grub or initramfs?  My Linux skills are a little rusty - any help would be appreciated.
0
Hi all i have installed Ubuntu server on a azure VM and opened port 3306 but cant seem to connect to my myphpadmin or sql server remotely i have also turneed of the firewall on the server to confirm this is not a issue, any help would be great
0
While doing initial testing of for an upcoming database server migration, we were surprised to find that the “new”, much better, machine is underperforming compared to the “old”, production, environment.     Specifically, we found that ALTER operations run significantly slower in the new.  A 1.9Gb table with 25407229 records took 2m 15s to complete an ALTER query ( ALTER TABLE _tmp_table ENGINE=InnoDB; ) in the “old” machine, while the same query took 7m 38s in the “new” machine.  Tests were performed when both machines experienced minimal load.     We appreciate any information or ideas that could explain (and solve) the observed underperformance.    

Thanks    

“Old” server specifications:
Dell PowerEdge R920
Processor: Cores (40) - Intel(R) Xeon(R) CPU E7-8891 v2 @ 3.20GHz
Ubuntu 14.04.1 LTS  Percona 5.6.22
RAM: 1511 GB
HDD: 598.9 GB + 1199.1 GB

“New” server specifications:
Dell PowerEdge R640
Processor: Cores (32) - Intel(R) Xeon(R) Gold 6244 CPU @ 3.60GHz
Ubuntu 18.04.3 LTS  Percona 5.7.28  
RAM: 1510 GB
SSD: 3.5 TB  


/etc/mysql/percona-server.conf.d/mysqld.cnf

skip-name-resolve
back_log = 1500
innodb_adaptive_hash_index = 0
innodb_buffer_pool_instances = 64
innodb_buffer_pool_size = 710G
innodb_flush_method = O_DIRECT
innodb_flush_neighbors = 0
innodb_io_capacity = 15000
innodb_io_capacity_max = 25000
innodb_lru_scan_depth = 8192
innodb_open_files = 2000
innodb_page_cleaners = 8
join_buffer_size = 600M
key_buffer_size = 6000M
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i update my nextcloud on ubuntu (LXD) to version 17 from 16 successfully.
But all user and admin has a following error:
"Invalid private key for encryption app. Please update your private key password in your personal settings to recover access to your encrypted files. "
i do not have enable server-side encryption .
we have only Default encryption module.
What is wrong here?
0
i have nextcloud version 17 on ubuntu 18.04 (lxd).
How to set microsoft word as default on it.
i have install the only word app and the app is enabled. but i can't see word ad a default.
0
I'm using the code proposted by Sarabande in one of my previous questions Read and Write on Serial Port under Ubuntu and C/C++ and it works very well even if I found out that sometimes the code stucks immediately before the while() loop without throwing any errors, it just get stuck and nothing happens. Then I run again the code and it works fine.

The device connected to the serial port is a digital scale and it works in this way when it receives
READ<CR><LF>

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:
01ST,GS, 0.0,kg<CR><LF>
where
01       code to use only for 485 communications
ST             scale status:
            US - measurement not stable
            ST - measurement stable
            OL - overload weight
            UL - underload weight
            TL - scale non balanced
,              ASCII 044
GS Tipo di dato di peso (2 chars)
,              ASCII 044
0.0             weight
,              ASCII 044
kg             measurement unit (2 caratteri)
<CR><LF> end of packet ASCII 013 e ASCII 010

Why the serial read gets stuck sometimes?
Is there any way to detect if the while() loop is not working in order to skip the operation?
Can it be related to the parameters of the serial port?

This is my current code:
char buf[80] = {'\0' }; 
int set_interface_attribs(int fd, int speed)
{
    struct termios tty;

    if (tcgetattr(fd, &tty) < 0) {
        printf("Error from tcgetattr: %s\n", 

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0
I need to migrate my wordpress site to reside on the same UBUNTU 18.04 server with SuiteCRM running PHP Version 7.2.19-0; Ubuntu 18.04.2

I have a /var/www/html directory on the target server where the suitecrm folder is located.

I am not sure where I restore my wp-admin, wp-content & wp-includes directories and wp-*.php files.  Do these get copied to this /var/www/html/ folder and update the refs in the wp-config.php file?

The database has been copied into the same MySQL server that the SuiteCRM is stored in.
0
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Inherited a Ubuntu server and trying to access/see what is on VG00-backups and VG00-Var

unix
As i understand it, VG00-Backups and -Var are both Logical volumes (mounted to the backup and var partitions). Both are using a lot of space and I like to know what utilizing that space but I'm not sure how i can access it. I've tried get into it but I get the "it's not a directory" error when I try to CD to it.
0
hi my vm is blur not clear after runnin this comand xrandr -s 1600x1200
ubuntu
0
hi no internat in my ubuntu vm
internat32
0
hi am not able to connect to my vm via putty
putty
0
hi am not able to ssh
ssh
0
Hello,
I get always this error on my postfix: Out: 250 2.0.0 Ok
 In:  AUTH LOGIN
 Out: 334 VXNlcm5hbWU6
 In:  dGVzdDFAaXAtMTQ3LTEzNS0yMjcuZXU=
 Out: 334 UGFzc3dvcmQ6
 In:  dGVzdDExMTE=
 Out: 535 5.7.8 Error: authentication failed: authentication failure
 In:  RSET
 Out: 250 2.0.0 Ok
 In:  AUTH LOGIN
 Out: 334 VXNlcm5hbWU6
 In:  dGVzdDFAaXAtMTQ3LTEzNS0yMjcuZXU=
 Out: 334 UGFzc3dvcmQ6
 In:  dGVzdDEyMjI=
 Out: 535 5.7.8 Error: authentication failed: authentication failure
 In:  RSET
 Out: 250 2.0.0 Ok
 In:  AUTH LOGIN
 Out: 334 VXNlcm5hbWU6
 In:  dGVzdDFAaXAtMTQ3LTEzNS0yMjcuZXU=
 Out: 334 UGFzc3dvcmQ6
 In:  dGVzdDEzMzM=
 Out: 535 5.7.8 Error: authentication failed: authentication failure
 In:  RSET
 Out: 250 2.0.0 Ok
 In:  AUTH LOGIN
 Out: 334 VXNlcm5hbWU6
 In:  dGVzdDFAaXAtMTQ3LTEzNS0yMjcuZXU=
 Out: 334 UGFzc3dvcmQ6
 In:  JW51bGwl
 Out: 535 5.7.8 Error: authentication failed: authentication failure
 In:  RSET
 Out: 250 2.0.0 Ok
 In:  AUTH LOGIN
 Out: 334 VXNlcm5hbWU6
 In:  dGVzdDFAaXAtMTQ3LTEzNS0yMjcuZXU=
 Out: 334 UGFzc3dvcmQ6
 In:  MTIz
 Out: 535 5.7.8 Error: authentication failed: authentication failure
 In:  RSET
 Out: 250 2.0.0 Ok
 In:  AUTH LOGIN
 Out: 334 VXNlcm5hbWU6
 In:  dGVzdDFAaXAtMTQ3LTEzNS0yMjcuZXU=
 Out: 334 UGFzc3dvcmQ6
 In:  MTIzMTIz
 Out: 535 5.7.8 Error: authentication failed: authentication failure
 In:  RSET
 Out: 250 2.0.0 Ok
 In:  AUTH LOGIN
 Out: 334 VXNlcm5hbWU6
 In:  dGVzdDFAaXAtMTQ3LTEzNS0yMjcuZXU=
0
Reopening this question.  I thought the issue was fixed, but it persists.

I am seeing a strange issue with sssd on Ubuntu 16.04.  I am using sssd to authenticate to AD.  The logins work great and is almost instantaneous as long as you have recently logged in (within the last minute or two).  If you wait longer between logins, then it will login you into, but you do not get a prompt for up to 30 seconds.

Note that these systems are in Azure and our AD is also in Azure.

I am using offline caching and setting the site.  I am stumped as to how to correct this issue.

Below are my conf files (sanitized for security).

-----------------------------------------------------------------------------------------
/etc/sssd/sssd.conf

[sssd]
services = pam, nss
config_file_version = 2
domains = xxxx.COM
#debug_level = 7

[domain/XXXX.COM]
dyndns_update = False
id_provider = ad
auth_provider = ad
access_provider = ad
krb5_realm = xxxx.COM
#debug_level = 4
default_shell = /bin/bash
ad_site = AH
cache_credentials = True
ad_enable_gc = False

# Use this if users are being logged in at /.
# This example specifies /home/DOMAIN-FQDN/user as $HOME.  Use with pam_mkhomedir.so
override_homedir = /home/XXXX/%u

# Uncomment if the client machine hostname doesn't match the computer object on the DC.
# ad_hostname = mymachine.myubuntu.example.com

# Uncomment if DNS SRV resolution is not workin#g
# ad_server = _srv_

# Uncomment if the AD domain is …
0
I'm new to Glusterfs in general. We have chosen to use it as our distributed file system on a new set of HA file servers.

The setup is:
  • 2 SUPERMICRO SuperStorage Server 6049PE1CR36L with 24-4TB spinning disks and NVMe for cache and slog.
  • HBA not RAID card
  • Ubuntu 18.04 server (on both systems)
  • ZFS filestorage
  • Glusterfs 5.10

Step one was to install Ubuntu, ZFS, and gluster. This all went without issue.
We have 3 ZFS raidz2 identical on both servers
We have three glusterfs mirrored volumes - 1 attached to each raidz on each server. I.e.

And mounted the gluster volumes as (for example) "/glusterfs/homes -> /zpool/homes". I.e.
gluster volume create homes replica 2 transport tcp server1:/zpool-homes/homes server2:/zpool-homes/homes force
(on server1) server1:/homes     44729413504 16032705152 28696708352  36% /glusterfs/homes


The problem is, the performance has deteriorated terribly.

We needed to copy all of our data from the old server to the new glusterfs volumes (appx. 60TB).
We decided to do this with multiple rsync commands (like 400 simultanous rsyncs)
The copy went well for the first 4 days, with an average across all rsyncs of  150-200 MBytes per second.
Then, suddenly, on the fourth day, it dropped to about 50 MBytes/s.
Then, by the end of the day, down to ~5MBytes/s (five).
I've stopped the rsyncs, and I can still copy an individual file across to the glusterfs shared directory at 100MB/s.
But actions such as "ls -la" or "find" take forever!
0
Hello,
how I can block ip in ubuntu regarding list file ?
thanks.
0
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i ubuntu 16.04( lxd ) i have a jar file. normally i create a link in /etc/init.d from jar file and systemctl daemon-reload, then i start my jar service(systemctl start "mt-service"
i did also here but servoces mark exited and say Docs: man:systemd-syv-generator(8).
...
What is wrong here?
0
I'm using C++,  WxWdigets and Ubuntu and sometimes my application needs to send TCP packets to a TCP server.
The packets are in this format:
std::array<uint8_t, 8> command1;

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I'm using a non-blocking TCP client method from boost asio and it works pretty well.
The problem is that I need to change the content of command1 since I need to send 32 different values depending on users actions.

At the moment, I connect to the server by using start_connection() function which connects to the server and execute the function start_write(int scelta) which sends the command1 over the net.

I would like to call the start_connection() function by passing the value of command1 in order to send it with start_write() function.
Is there any solution to do this?
Or, is there a smarter and faster solution to acquire what I need?

#include <boost/asio/buffer.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/read_until.hpp>
#include <boost/asio/steady_timer.hpp>
#include <boost/asio/write.hpp>
#include <boost/bind.hpp>
#include <iostream>
#include <string>

using boost::asio::steady_timer;
using boost::asio::ip::tcp;

std::array<uint8_t, 8> command1;

class client
{
public:
  client(boost::asio::io_context& io_context)
    : stopped_(false),
      socket_(io_context),
      deadline_(io_context),
      heartbeat_timer_(io_context)
  {
  }

 
  void start(tcp::resolver::results_type

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0
samba failed to start on ubuntu 16.04 server
system status smbd :
Failed to start LSB: start Samba SMB/CIFS daemon (smbd)
i reinstall install samba krb5-config krb5-user winbind libpam-winbind libnss-winbind
 
get error
Errors were encountered while processing:
 samba
 winbind
 libnss-winbind:amd64
 libpam-winbind:amd64
 samba-dbg
 initramfs-tools
 linux-image-4.4.0-166-generic
E: Sub-process /usr/bin/dpkg returned an error code (1)
0
ubuntu 16 under update failed :
dpkg: error processing package linux-image-4.4.0-166-generic (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 initramfs-tools
 linux-image-4.4.0-166-generic
E: Sub-process /usr/bin/dpkg returned an error code (1)

And i can't install samba and winbind on it.
0
I'm using WxWidgets 3.1.2 with C++ under Ubuntu to control a device which acts like a Kiosk/ATM.
I use a magnetic card reader to take inputs from the users within the first frame (ProjectMain.cpp) and then I have two other frames (SecondPage.cpp and ThirdPage.cpp) where the users can perform some actions (i.e. press buttons, insert text and so on).
At the end of this procedure, the application destroys the third frame and reloads the first frame to start a new operation with a new user.

I use wx/timer.h in order to trigger a reset function if the user do nothing for more than 5 minutes; after this time, I load the first frame again.
I put the time trigger function in the frame creation function so the timer starts as soon as the frame is loaded; I use the trigger also when some buttons are pressed.
It works very fine, but sometimes I noticed that the application resets by itself (even if T << 5 minutes) and it loads new windows in the application bar.
If I press ALT+TAB, I can see several instances of the same application and this is very strange to me.

I'm pretty sure the problem is related to the timer function, but I cannot understand how to solve it.
Can you help me, please? I need to solve this problem very urgently, but I don't know what do do.

P.S. Moreover, when only the first frame is loaded, I can see that the timer on the secondpage starts, too. But, how can this possible since Frame2 is not loded yet?

ProjectApp.cpp
#include "ProjectApp.h"

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0
i install nfs-server on ubuntu desktop 18.04
then share a directory on /etc/expports:
/mnt/sharedirectory client-ip(rw,sync,no_subtree_check)

from client ip i try to mount shared directory
mount -t nfs desktop-ip:/mnt/sharedirestory /mnt/srchive/
 mount.nfs: Connection timed out
nothing is in my auth.log or syslog.
from that client i mountet directories from other server . Then error should be in my desktop. But i can't see any.
0

Ubuntu

373

Solutions

423

Contributors

Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things.