[CentOS] odd popups

[Fred Smith]

Occasionally and without any action on my part, I get a popup
saying I need to authenticate in order to read others' actions.
I have no clue what this is for, so I always reject them.
Anyone got a clue?

Image attached.

-- 
 Fred Smith -- fre...@fcshome.stoneham.ma.us -
   But God demonstrates his own love for us in this: 
 While we were still sinners, 
  Christ died for us.
--- Romans 5:8 (niv) --
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[CentOS] Centos 7 - Canon Powershot A410

[Frank Cox]

I have an old Canon Powershot A410 camera that used to just work with
Centos 6.  All I had to do was install Shotwell and forever after I
could just plug that camera in and Shotwell would automatically load and
all was well.

I'm now trying to get that camera to work on Centos 7, but am having no
success.

Jul 20 16:01:44 jeff kernel: usb 2-1.3: new full-speed USB device number
4 using ehci-pci
Jul 20 16:01:44 jeff kernel: usb 2-1.3: New USB device found, idVendor=04a9, idP
roduct=30f9
Jul 20 16:01:44 jeff kernel: usb 2-1.3: New USB device strings: Mfr=1, Product=2
, SerialNumber=0
Jul 20 16:01:44 jeff kernel: usb 2-1.3: Product: Canon Digital Camera
Jul 20 16:01:44 jeff kernel: usb 2-1.3: Manufacturer: Canon Inc.
Jul 20 16:01:44 jeff mtp-probe: checking bus 2, device 4: "/sys/devices/pci:
00/:00:1d.0/usb2/2-1/2-1.3"
Jul 20 16:01:44 jeff mtp-probe: bus: 2, device: 4 was not an MTP device

That last line isn't surprising because this camera apparently used PTP
and not MTP.

So does anyone know how to enable PTP mode?  As far as I can tell the
(installed) libgphoto2-2.5.15-1.el7.x86_64 is supposed to support PTP
mode cameras but somehow it's not being activated or something?

-- 
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Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[Valeri Galtsev]

On 07/19/18 09:14, Johnny Hughes wrote:

On 07/18/2018 04:05 PM, Valeri Galtsev wrote:



On 07/18/18 14:36, Johnny Hughes wrote:

On 07/18/2018 01:58 PM, Valeri Galtsev wrote:





But are you guys really telling you think the calendaring / scheduling
for individual users and the main corporate account, etc. .. are
working
well enough with any Linux solution.


I must confess, my servers are FreeBSD, but I'm quite sure the same is
doable easily on Linux.

We use for calendars Owncloud (may migrate to nextcloud in some future
to come). That authenticates against LDAP.


And does that calendar solution allow for things like:

1)  Allowing all users in the organization to see users calendars and
see when they are free to schedule a meeting with them.


Yes at least about a part of it: calendars can be shared with some
people or with everybody (which we didn't do, so I may be not 100%
presenting "experimental fact" here). Not certain about "free/not free"
mapped on calendars though.



2) Allow for designated people to schedule meetings for others (ie, your
secretary/office assistant can schedule meetings for people, etc.)


Yes, you can share calendar with anybody, and can set any set of choices

can read
can write
can "re-share" your calendar

You can share stuff to external people, and set individual
authentication for them independent of our system (in general, it is not
just calendars, but we use it for mostly synchronizing between all of
your devices, and also sharing: files, calendars, address book; it can
also be bookmarks, and there are variety of plugins expanding what else
can be accessed/synchronized via web/dav)



3) Allow a calendar to schedule shared items .. like meeting rooms,
shared vehicles, etc.  So that people can check those out for specifc
time windows, etc.


No, but for resource booking (if I read the question correctly) we use
mrbs (https://mrbs.sourceforge.io/). I know, that is not "integrated"
for you to have everything in one place. I never had time to look for
extention/plugin to suck from mrbs booked slot into one's calendar.



Those are just a couple of minor things a lot of solutions can't do

And do they work with imap, etc.


No, owncloud/nextcloud don't work with IMAP as far as I know. Mail
server is separate issue. Zimbra in that respect IS "integrated
collaborative environment". And so is Kolab. They both are lacking
per-user spam preferences. One more thing that added some minus for each
of them in my estimate what to choose is: behind each of them there is
commercial company. And that in my long experience significantly
increases the chance one day openly available incarnation of each may
become no longer available for us, and I will have to find replacement
in a rush and find the way to migrate to it, and the more sophisticated
the thing is, the trickier the migration will be.

My answers are mostly about owncloud which we use for quite some time.
Nextcloud is fork of owncloud, and to my regret nextcloud doesn't work
with postgresql, only with mysql/MariaDB, whereas owncloud works with
postgresql as well as with mysql/MariaDB (still we have some reasons to
migrate to nextcloud at some point).

I hope, someone with more knowledge will chime in.




Don't get me wrong.  I've run qmail, postfix, and zimbra mail servers
with IMAP, along with webmail front ends (roundcude, squirrel mail,
etc), for windows, mac and linux clients for several companies (all on
CentOS of course :D) .. I just don't think that calendaring that I have
seen is as user friendly as google calendar (for example).  But I'm all
for people running mail servers on CentOS (or any other Linux) if they
want !




Zimbra does not work very well with
Thunderbird and Lighting (for example) .. many solutions don't work with
Windows or Mac clients, etc.




For mail we use postfix, dovecot and maia for spam filtering (the last
harnesses spamassassin, clamav and few other things).

Of course, zimbra you mentioned earlier in the thread (or was it not
you?), and Kolab provide more corporate-like collaboration environments,
but I shied away from them as I set myself a goal to give users
individual handle on spam/virus filtering in email, and neither of them
has per-user spam preferences (take it with the grain of salt, I might
have missed something...)

Just my $0.02.







My belated addition. This is great overview of nextcloud vs ovncloud 
features (which makes evident the set of abilities of each):


https://civihosting.com/blog/nextcloud-vs-owncloud/

Valeri




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--

Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247

___
CentOS 

Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[Keith Keller]

On 2018-07-20, Nicolas Kovacs  wrote:
> Le 20/07/2018 à 07:44, Keith Keller a écrit :
>> A public SMTP server is not the easiest thing to configure, period. 
>> It is the quintessential rope on which many admins hang themselves.
>
> It's not rocket science either, but you have to be willing to read (a
> lot) and experiment (a lot).

You also need to be willing to stay on top of your outgoing mail to make
sure your network isn't sending spam, and you need to monitor the
various blacklists to make sure your SMTP servers are not ending up on
them.  It's not like (for example) an IMAP server, which once you have
working is mostly maintenance-free.

--keith

-- 
kkel...@wombat.san-francisco.ca.us


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Re: [CentOS] Is there any way I can deploy cPanel web hosting control panel with Microsoft Exchange 2016 groupware behind one static public IP?

[Alexander Dalloz]

Am 20.07.2018 um 19:18 schrieb Turritopsis Dohrnii Teo En Ming:

Dear Richard Grainger,


I am grateful for your reply and guidance.


After reading the following article at nginx.com, I realize that I should use a 
reverse proxy instead of a load balancer.


Article: WHAT IS A REVERSE PROXY VS. LOAD BALANCER?

Link:https://www.nginx.com/resources/glossary/reverse-proxy-vs-load-balancer/


Presently, I am using pfSense community edition firewall. Can I install the 
Squid package and use it as a reverse proxy? Where can I find good installation 
and configuration guides on this topic?


Based on what you have mentioned, it seems that reverse proxy can only be used 
for HTTP and HTTPS protocols.


Can I use reverse proxy for DNS, IMAP, IMAP/S, POP3, POP3/S, SMTP and SMTP/s as 
well?


So requests for domain1.com goes to all services/protocols in cPanel. And 
requests for domain2.com goes to all services/protocols in Exchange 2016.


Is that possible? Please advise.


Thank you very much.


Hello,

you are asking about solutions which have not much if even anything to 
do with CentOS and the purpose of this mailing list. While it is good 
that you want to learn you may better contact people near you to discuss 
things like pfSense and cPanel and Exchange or hire a consultant.


Alexander

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Re: [CentOS] Is there any way I can deploy cPanel web hosting control panel with Microsoft Exchange 2016 groupware behind one static public IP?

[Turritopsis Dohrnii Teo En Ming]

Seems like I can install nginx on a virtual machine and port forward from my 
pfsense firewall to it, according to the following article.


Article: Set up Nginx Reverse Proxy

Link: https://www.techandme.se/set-up-nginx-reverse-proxy/





From: Turritopsis Dohrnii Teo En Ming
Sent: Saturday, July 21, 2018 1:29 AM
To: CentOS mailing list
Cc: Turritopsis Dohrnii Teo En Ming
Subject: Re: [CentOS] Is there any way I can deploy cPanel web hosting control 
panel with Microsoft Exchange 2016 groupware behind one static public IP?


Hi,


Based on further research, it appears that Squid can only reverse proxy HTTP 
and HTTPs but NGINX is able to reverse proxy IMAP, POP3, and SMTP protocols.


Please correct me if I am wrong.


Thank you.


===BEGIN SIGNATURE===

Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017

[1] https://tdtemcerts.wordpress.com/

[2] http://tdtemcerts.blogspot.sg/

[3] 
https://www.scribd.com/user/270125049/Teo-En-Ming

===END SIGNATURE===



From: Turritopsis Dohrnii Teo En Ming
Sent: Saturday, July 21, 2018 1:18 AM
To: CentOS mailing list
Cc: Turritopsis Dohrnii Teo En Ming
Subject: Re: [CentOS] Is there any way I can deploy cPanel web hosting control 
panel with Microsoft Exchange 2016 groupware behind one static public IP?


Dear Richard Grainger,


I am grateful for your reply and guidance.


After reading the following article at nginx.com, I realize that I should use a 
reverse proxy instead of a load balancer.


Article: WHAT IS A REVERSE PROXY VS. LOAD BALANCER?

Link: https://www.nginx.com/resources/glossary/reverse-proxy-vs-load-balancer/


Presently, I am using pfSense community edition firewall. Can I install the 
Squid package and use it as a reverse proxy? Where can I find good installation 
and configuration guides on this topic?


Based on what you have mentioned, it seems that reverse proxy can only be used 
for HTTP and HTTPS protocols.


Can I use reverse proxy for DNS, IMAP, IMAP/S, POP3, POP3/S, SMTP and SMTP/s as 
well?


So requests for domain1.com goes to all services/protocols in cPanel. And 
requests for domain2.com goes to all services/protocols in Exchange 2016.


Is that possible? Please advise.


Thank you very much.


===BEGIN SIGNATURE===

Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017

[1] https://tdtemcerts.wordpress.com/

[2] http://tdtemcerts.blogspot.sg/

[3] https://www.scribd.com/user/270125049/Teo-En-Ming

===END SIGNATURE===



From: CentOS  on behalf of Richard Grainger 

Sent: Saturday, July 21, 2018 12:29 AM
To: CentOS mailing list
Subject: Re: [CentOS] Is there any way I can deploy cPanel web hosting control 
panel with Microsoft Exchange 2016 groupware behind one static public IP?

You can use bind your cPanel web server to a different port or
(better) you can put your services behind a reverse proxy/load
balancer. In this scenario, for web servers running on the standard
ports (ie TCP 80 and 443), you can use HTTP host headers/SNI to
redirect requests to the appropriate backend web server based on the
domain name used.

So yes, you can have a whole bunch of stuff running behind one public
IP address if you're willing to cope with the complexity.  But
sometimes life is simpler if you can use more.
On Thu, Jul 19, 2018 at 4:45 PM Turritopsis Dohrnii Teo En Ming
 wrote:
>
> Good evening from Singapore,
>
>
> Is there any way I can deploy cPanel web hosting control panel with Microsoft 
> Exchange 2016 groupware behind one static public IP? Or do I need 2 static 
> public IP addresses at the minimum? With Exchange 2016 groupware taking up 
> HTTP, HTTPS, IMAP, IMAPS, POP3, POP3S, SMTP, and SMTP/S ports, I personally 
> don't think I can deploy cPanel behind the same public IP as Exchange.
>
>
> Please advise. Perhaps you have a brilliant idea. This is for experimental, 
> testing and laboratory purposes.
>
>
> Thank you very much.
>
>
> ===BEGIN SIGNATURE===
>
> Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017
>
> [1] https://tdtemcerts.wordpress.com/
[https://s0.wp.com/i/blank.jpg]

Turritopsis Dohrnii Teo En Ming's Academic Qualifications – Historical Records, 
Office of the Grand Historian
tdtemcerts.wordpress.com
Historical Records, Office of the Grand Historian



>
> [2] http://tdtemcerts.blogspot.sg/
>
> [3] 
> https://www.scribd.com/user/270125049/Teo-En-Ming
>
> ===END SIGNATURE===
> ___
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Re: [CentOS] Is there any way I can deploy cPanel web hosting control panel with Microsoft Exchange 2016 groupware behind one static public IP?

[Turritopsis Dohrnii Teo En Ming]

Hi,


Based on further research, it appears that Squid can only reverse proxy HTTP 
and HTTPs but NGINX is able to reverse proxy IMAP, POP3, and SMTP protocols.


Please correct me if I am wrong.


Thank you.


===BEGIN SIGNATURE===

Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017

[1] https://tdtemcerts.wordpress.com/

[2] http://tdtemcerts.blogspot.sg/

[3] 
https://www.scribd.com/user/270125049/Teo-En-Ming

===END SIGNATURE===



From: Turritopsis Dohrnii Teo En Ming
Sent: Saturday, July 21, 2018 1:18 AM
To: CentOS mailing list
Cc: Turritopsis Dohrnii Teo En Ming
Subject: Re: [CentOS] Is there any way I can deploy cPanel web hosting control 
panel with Microsoft Exchange 2016 groupware behind one static public IP?


Dear Richard Grainger,


I am grateful for your reply and guidance.


After reading the following article at nginx.com, I realize that I should use a 
reverse proxy instead of a load balancer.


Article: WHAT IS A REVERSE PROXY VS. LOAD BALANCER?

Link: https://www.nginx.com/resources/glossary/reverse-proxy-vs-load-balancer/


Presently, I am using pfSense community edition firewall. Can I install the 
Squid package and use it as a reverse proxy? Where can I find good installation 
and configuration guides on this topic?


Based on what you have mentioned, it seems that reverse proxy can only be used 
for HTTP and HTTPS protocols.


Can I use reverse proxy for DNS, IMAP, IMAP/S, POP3, POP3/S, SMTP and SMTP/s as 
well?


So requests for domain1.com goes to all services/protocols in cPanel. And 
requests for domain2.com goes to all services/protocols in Exchange 2016.


Is that possible? Please advise.


Thank you very much.


===BEGIN SIGNATURE===

Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017

[1] https://tdtemcerts.wordpress.com/

[2] http://tdtemcerts.blogspot.sg/

[3] https://www.scribd.com/user/270125049/Teo-En-Ming

===END SIGNATURE===



From: CentOS  on behalf of Richard Grainger 

Sent: Saturday, July 21, 2018 12:29 AM
To: CentOS mailing list
Subject: Re: [CentOS] Is there any way I can deploy cPanel web hosting control 
panel with Microsoft Exchange 2016 groupware behind one static public IP?

You can use bind your cPanel web server to a different port or
(better) you can put your services behind a reverse proxy/load
balancer. In this scenario, for web servers running on the standard
ports (ie TCP 80 and 443), you can use HTTP host headers/SNI to
redirect requests to the appropriate backend web server based on the
domain name used.

So yes, you can have a whole bunch of stuff running behind one public
IP address if you're willing to cope with the complexity.  But
sometimes life is simpler if you can use more.
On Thu, Jul 19, 2018 at 4:45 PM Turritopsis Dohrnii Teo En Ming
 wrote:
>
> Good evening from Singapore,
>
>
> Is there any way I can deploy cPanel web hosting control panel with Microsoft 
> Exchange 2016 groupware behind one static public IP? Or do I need 2 static 
> public IP addresses at the minimum? With Exchange 2016 groupware taking up 
> HTTP, HTTPS, IMAP, IMAPS, POP3, POP3S, SMTP, and SMTP/S ports, I personally 
> don't think I can deploy cPanel behind the same public IP as Exchange.
>
>
> Please advise. Perhaps you have a brilliant idea. This is for experimental, 
> testing and laboratory purposes.
>
>
> Thank you very much.
>
>
> ===BEGIN SIGNATURE===
>
> Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017
>
> [1] https://tdtemcerts.wordpress.com/
[https://s0.wp.com/i/blank.jpg]

Turritopsis Dohrnii Teo En Ming's Academic Qualifications – Historical Records, 
Office of the Grand Historian
tdtemcerts.wordpress.com
Historical Records, Office of the Grand Historian



>
> [2] http://tdtemcerts.blogspot.sg/
>
> [3] 
> https://www.scribd.com/user/270125049/Teo-En-Ming
>
> ===END SIGNATURE===
> ___
> CentOS mailing list
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Re: [CentOS] Is there any way I can deploy cPanel web hosting control panel with Microsoft Exchange 2016 groupware behind one static public IP?

[Turritopsis Dohrnii Teo En Ming]

Dear Richard Grainger,


I am grateful for your reply and guidance.


After reading the following article at nginx.com, I realize that I should use a 
reverse proxy instead of a load balancer.


Article: WHAT IS A REVERSE PROXY VS. LOAD BALANCER?

Link: https://www.nginx.com/resources/glossary/reverse-proxy-vs-load-balancer/


Presently, I am using pfSense community edition firewall. Can I install the 
Squid package and use it as a reverse proxy? Where can I find good installation 
and configuration guides on this topic?


Based on what you have mentioned, it seems that reverse proxy can only be used 
for HTTP and HTTPS protocols.


Can I use reverse proxy for DNS, IMAP, IMAP/S, POP3, POP3/S, SMTP and SMTP/s as 
well?


So requests for domain1.com goes to all services/protocols in cPanel. And 
requests for domain2.com goes to all services/protocols in Exchange 2016.


Is that possible? Please advise.


Thank you very much.


===BEGIN SIGNATURE===

Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017

[1] https://tdtemcerts.wordpress.com/

[2] http://tdtemcerts.blogspot.sg/

[3] https://www.scribd.com/user/270125049/Teo-En-Ming

===END SIGNATURE===



From: CentOS  on behalf of Richard Grainger 

Sent: Saturday, July 21, 2018 12:29 AM
To: CentOS mailing list
Subject: Re: [CentOS] Is there any way I can deploy cPanel web hosting control 
panel with Microsoft Exchange 2016 groupware behind one static public IP?

You can use bind your cPanel web server to a different port or
(better) you can put your services behind a reverse proxy/load
balancer. In this scenario, for web servers running on the standard
ports (ie TCP 80 and 443), you can use HTTP host headers/SNI to
redirect requests to the appropriate backend web server based on the
domain name used.

So yes, you can have a whole bunch of stuff running behind one public
IP address if you're willing to cope with the complexity.  But
sometimes life is simpler if you can use more.
On Thu, Jul 19, 2018 at 4:45 PM Turritopsis Dohrnii Teo En Ming
 wrote:
>
> Good evening from Singapore,
>
>
> Is there any way I can deploy cPanel web hosting control panel with Microsoft 
> Exchange 2016 groupware behind one static public IP? Or do I need 2 static 
> public IP addresses at the minimum? With Exchange 2016 groupware taking up 
> HTTP, HTTPS, IMAP, IMAPS, POP3, POP3S, SMTP, and SMTP/S ports, I personally 
> don't think I can deploy cPanel behind the same public IP as Exchange.
>
>
> Please advise. Perhaps you have a brilliant idea. This is for experimental, 
> testing and laboratory purposes.
>
>
> Thank you very much.
>
>
> ===BEGIN SIGNATURE===
>
> Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017
>
> [1] https://tdtemcerts.wordpress.com/
[https://s0.wp.com/i/blank.jpg]

Turritopsis Dohrnii Teo En Ming's Academic Qualifications – Historical Records, 
Office of the Grand Historian
tdtemcerts.wordpress.com
Historical Records, Office of the Grand Historian



>
> [2] http://tdtemcerts.blogspot.sg/
>
> [3] 
> https://www.scribd.com/user/270125049/Teo-En-Ming
>
> ===END SIGNATURE===
> ___
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Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[Nicolas Kovacs]

Le 20/07/2018 à 09:12, Promise Kumalo a écrit :
> Just out of curiosity, why are you not using something like Kolab or
> Zimbra?

Don't know. Never tried these, because I'm comfortable with Postfix,
Dovecot and Spamassassin. I might give these a spin though.

Thanks for the heads up.

Niki

-- 
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7, place de l'église - 30730 Montpezat
Site : https://www.microlinux.fr
Blog : https://blog.microlinux.fr
Mail : i...@microlinux.fr
Tél. : 04 66 63 10 32
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Re: [CentOS] database node / possible SYN flooding on port 3306

[Nataraj]

On 07/20/2018 03:56 AM, Leon Fauster via CentOS wrote:
> Hi folks,
>
> I have here a database node running
>
> # rpm -qa | grep mysql-server
> mysql55-mysql-server-5.5.52-1.el6.x86_64
>
> on
>
> # virt-what 
> vmware
>
>
> that seems to have a connection problem:
>
> # dmesg |grep SYN |tail -5
> possible SYN flooding on port 3306. Sending cookies.
> possible SYN flooding on port 3306. Sending cookies.
> possible SYN flooding on port 3306. Sending cookies.
> possible SYN flooding on port 3306. Sending cookies.
> possible SYN flooding on port 3306. Sending cookies.
>
>
> I adapted already following:
>
> # sysctl -a |grep -E 'maxconn|syn_backlog'
> net.core.somaxconn = 2048
> net.ipv4.tcp_max_syn_backlog = 2048
>
>
> but ListenOverflows and ListenDrops values are still high
>  
> # cat /proc/net/netstat | awk '{print $21 "-" $22 }'
> ListenOverflows-ListenDrops
> 13568-13568
>
> any suggestion? 

Use tools like tcpdump/wireshark  and further examination of logfiles to
determine where your attack is coming from, i.e. single IP address or
multiple ip addresses (BOT attack).

If attack is impairing your Internet service, contact your ISP.  Most
decent ISP's should deal with this situation for you.

If attack is not impairing your service and you choose to deal with it
yourself, then, if from a fixed IP address block that IP from your
firewall if you have one, otherwise, use IPtables on the server.  If
your having bot attacks, or blocking attack causes source IP address to
be changed, then look at fail2ban.  Basically you want to configure
fail2ban to limit the number of requests per unit of time and block IPs
that exceed that.  Also, consider weather your database needs to be
publicly accessible from the Internet.

Nataraj


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Re: [CentOS] Is there any way I can deploy cPanel web hosting control panel with Microsoft Exchange 2016 groupware behind one static public IP?

[Richard Grainger]

You can use bind your cPanel web server to a different port or
(better) you can put your services behind a reverse proxy/load
balancer. In this scenario, for web servers running on the standard
ports (ie TCP 80 and 443), you can use HTTP host headers/SNI to
redirect requests to the appropriate backend web server based on the
domain name used.

So yes, you can have a whole bunch of stuff running behind one public
IP address if you're willing to cope with the complexity.  But
sometimes life is simpler if you can use more.
On Thu, Jul 19, 2018 at 4:45 PM Turritopsis Dohrnii Teo En Ming
 wrote:
>
> Good evening from Singapore,
>
>
> Is there any way I can deploy cPanel web hosting control panel with Microsoft 
> Exchange 2016 groupware behind one static public IP? Or do I need 2 static 
> public IP addresses at the minimum? With Exchange 2016 groupware taking up 
> HTTP, HTTPS, IMAP, IMAPS, POP3, POP3S, SMTP, and SMTP/S ports, I personally 
> don't think I can deploy cPanel behind the same public IP as Exchange.
>
>
> Please advise. Perhaps you have a brilliant idea. This is for experimental, 
> testing and laboratory purposes.
>
>
> Thank you very much.
>
>
> ===BEGIN SIGNATURE===
>
> Turritopsis Dohrnii Teo En Ming's Academic Qualifications as at 30 Oct 2017
>
> [1] https://tdtemcerts.wordpress.com/
>
> [2] http://tdtemcerts.blogspot.sg/
>
> [3] 
> https://www.scribd.com/user/270125049/Teo-En-Ming
>
> ===END SIGNATURE===
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Re: [CentOS] bad text under KDE and C7

[Michael Hennebry]

On Tue, 17 Jul 2018, Pete Biggs wrote:


Check your hardware - all these things might well be symptomatic of an
hardware issue.


I'm not at all sure how.
If it means opening the case,
hardware issues are likely to occur.

Is there a way to tell whether the video
player is even using video acceleration?

--
Michael   henne...@web.cs.ndsu.nodak.edu
"Sorry but your password must contain an uppercase letter, a number,
a haiku, a gang sign, a heiroglyph, and the blood of a virgin."
 --  someeecards
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Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[Dave Stevens]

On Thu, 19 Jul 2018 09:57:22 -0500
Valeri Galtsev  wrote:

> 
> As far as google anything goes, not everybody volunteers one's 
> information into paws of google (and quite likely one or more of 3 
> letter agencies collecting information that way). I know (call it 
> educated guess) that about 70% of messages I send are ending up in 
> google databases whether I want it or not. Someone said quite some
> time ago: you don't need to recruit spies anymore, just roll out
> "free" services, and information will trickle to you. I am old enough
> to know what collection of information on everybody leads to (Hitler
> Germany, Stalin Russia, ...), but I also know that the worst lesson
> of history is: people do not learn lessons of history. So, I do the
> best I can do: roll out services people I work for may need, and
> avoid by any means advertising google whatever myself, I just keep
> neutral when that surfaces in discussions with my people.
> 

it's what Bertolt Brecht said, "Not everyone who shows you their teeth
is smiling."
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Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[James B. Byrne via CentOS]

On Thu, July 19, 2018 10:57, Valeri Galtsev wrote:

> 
> . . . you don't need to recruit spies anymore, just roll out "free"
> services, and information will trickle to you. I am old enough to know
> what collection of information on everybody leads to (Hitler Germany,
> Stalin Russia, ...), but I also know that the worst lesson of history
> is: people do not learn lessons of history. . .
> 

History is the practice of justifying the present by rewriting the past.

-- 
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[CentOS] database node / possible SYN flooding on port 3306

[Leon Fauster via CentOS]

Hi folks,

I have here a database node running

# rpm -qa | grep mysql-server
mysql55-mysql-server-5.5.52-1.el6.x86_64

on

# virt-what 
vmware


that seems to have a connection problem:

# dmesg |grep SYN |tail -5
possible SYN flooding on port 3306. Sending cookies.
possible SYN flooding on port 3306. Sending cookies.
possible SYN flooding on port 3306. Sending cookies.
possible SYN flooding on port 3306. Sending cookies.
possible SYN flooding on port 3306. Sending cookies.


I adapted already following:

# sysctl -a |grep -E 'maxconn|syn_backlog'
net.core.somaxconn = 2048
net.ipv4.tcp_max_syn_backlog = 2048


but ListenOverflows and ListenDrops values are still high
 
# cat /proc/net/netstat | awk '{print $21 "-" $22 }'
ListenOverflows-ListenDrops
13568-13568

any suggestion? 

--
Thanks,
LF


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Re: [CentOS] CentOS 7 + MATE : Folder contents not refreshed in file manager

[Nicolas Kovacs]

Le 13/07/2018 à 21:57, Liam O'Toole a écrit :
> What do you see in /proc/sys/fs/inotify/max_user_watches? If you
> increase the value, does the problem persist?

I investigated this, and indeed, it solved my problem.

I wrote a little blog article to summarize my findings and put you in
the Thank You notes.

https://blog.microlinux.fr/inotify/

Cheers,

Niki

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Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[Promise Kumalo]

Just out of curiosity, why are you not using something like Kolab or Zimbra?


On 07/20/2018 02:44 AM, Nicolas Kovacs wrote:
> Le 18/07/2018 à 17:04, Turritopsis Dohrnii Teo En Ming a écrit :
>> One of the features of Microsoft Exchange 2016 is that you can create
>> additional folders on your Inbox in the server (server-side). Can
>> Linux-based SMTP servers do that?
> I'm running a few bone-headed mail servers for schools and small
> companies. They're all bone-headed setups on CentOS. I'd say mail
> servers are not the easiest thing to configure under Linux. Anyway,
> here's all the ingredients I'm using.
>
>* https://blog.microlinux.fr/postfix-centos/
>
>* https://blog.microlinux.fr/dovecot-centos/
>
>* ttps://blog.microlinux.fr/postfix-dovecot-ssl-centos/
>
>* https://blog.microlinux.fr/spamassassin-centos/
>
>* https://blog.microlinux.fr/squirrelmail/
>
> Cheers,
>
> Niki
>

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Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[Nicolas Kovacs]

Le 20/07/2018 à 07:44, Keith Keller a écrit :
> A public SMTP server is not the easiest thing to configure, period. 
> It is the quintessential rope on which many admins hang themselves.

It's not rocket science either, but you have to be willing to read (a
lot) and experiment (a lot).

In France we have an expression for misconfigured public SMTP servers.

"Pompe à merde".

:o)

Niki

-- 
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7, place de l'église - 30730 Montpezat
Site : https://www.microlinux.fr
Blog : https://blog.microlinux.fr
Mail : i...@microlinux.fr
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Re: [CentOS] Which is better? Microsoft Exchange 2016 or Linux-based SMTP Servers?

[Keith Keller]

On 2018-07-19, Nicolas Kovacs  wrote:
> I'd say mail
> servers are not the easiest thing to configure under Linux.

A public SMTP server is not the easiest thing to configure, period.
It is the quintessential rope on which many admins hang themselves.


--keith
-- 
kkel...@wombat.san-francisco.ca.us


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