Solution
Be sure that jupyter-notebook is used instead of jupyter notebook, i.e.
ExecStart=/[pathOfTheBinary]/jupyter-notebook
or else it should be bracketed with quotation marks to ensure the space between jupyter and notebook is allowed.

Tricks

• Be sure that the path of the jupyter binary is correct
• Most of the info. on the web suggesting the content of jupyter.service file missed the fact that jupyter notebook is recommended to be run by non-root user, and it’s imperative that the location of jupyter configuration file must be specified in the jupyter.service file and not just the User=[jupyterUser] directive.

Config

• CentOS: 7-6
• jupyter: Anaconda3-5

The post Jupyter Notebook on Boot Automatically appeared first on LarryLai.

After installing a WordPress plugin – WP Health, it’s reminded that PHP5 had no longer been supported since late 2018, thus there may be risk in all WordPress websites.

Issue

Since removing PHP5 (retrospectively known that it’s not necessary), and installed remi’s repository’s PHP72, some WordPress sites could not be accessed with message: “Internal Server Error. The server encountered an internal error or misconfiguration and was unable to complete your request.” Then using VirtualBox’s snapshot to roll back and finally got every site back to normal.

However, using re-check configuration of Virtualmin to see if there’s anything need to follow up, it’s known that mod_actions of Apache wasn’t enabled. Then after enabling mod_actions by uncommenting the following:

LoadModule actions_module modules/mod_action.so

in /etc/httpd/conf.modules.d/00-base.conf, something weird that instead of executing php page, these pages were downloaded. Some members on forums suggested that the following in /etc/httpd/conf.d/php.conf should be commented out:

SetHandler application/x-httpd-php

This really solved the problem of not executing php pages, but another weird thing happened. Some other websites couldn’t be accessed again with message: 500 Internal Server Error.

Solution

1. The permission of some html directories all granted to 775 and changed owner as apache.
2. In Virtualmin, Server Config -> Website Options -> PHP script execution mode must select FPM if mod_fpm is installed and enable.

Tricks

Before comment out SetHandler application/x-httpd-php, directory permission was not a problem. What and how does something change the permission or why is the permission of html directories should be further granted to eliminated 500 Internal Server Error?

Config

• WordPress 5.1
• Virtualmin 6
• PHP7.2 remi
• CentOS7

The post PHP 7 & Related Issues appeared first on LarryLai.

Using MySQL-Workbench with version downloaded from standard OpenSUSE repository, there is nothing shown on Result Grid after successful execution of SQL statement, e.g. SELECT statement.

Solution:

The version provided by OpenSUSE repository is 6.1.7 is old and has bugs including nothing shown on Result Grid. After installing MySQL-Workbench 6.3.x, this serious problem is solved.

Tricks:

MySQL-workbench 6.3.x package depends on existence of some (probably) graphics packages, including libfreexl1, libgdal1, libgeos, libgeos_c1, libgeotiff2, libhdf5, libnetcdf7, libproj9, libspatialite7. All these cannot be found in OpenSUSE software repository. Without these packages being installed prior to installation of MySQL-workbench, warning will appear and installation will suspend. Also, the package libfreel1 will be easily typed incorrectly as libfreex11.

Config:

• OpenSUSE 13.2
• MySQL-Workbench 6.1.7 to 6.3.3

The post MySQL-Workbench Nothing Shown on Result Grid appeared first on LarryLai.

Email dropped silently or bounced back with notification:

Your message to [<user@domain.tld>] was automatically rejected:
Quota exceeded (mailbox for user is full)

It happened on mailbox of zPanel.

Solution:

1. Get postfix database password from the file: mysql-virtual_mailbox_limit_maps.cf located in /etc/zpanel/configs/postfix
2. login to phpMyAdmin and locate the database zpanel_postfix
3. browse the table: mailbox to locate the record with username going to increase the quota
4. change the column: quota from default 200 to larger value fitting the need

Tricks:

• Under Admin of zPanel, there is a way to change the Mail Config from Module Admin, however, the update to the value of Max Mailbox Size only applies to the new created email accounts, it has no effect to any existing email account.
• By using command: dovecot quota get -u [mailbox] to get the quota Limit and existing Value, we know if the quota limit has been increased properly
• In configuration file, dovecot.conf, imap_quota must be added to mail_plugins parameter within protocol imap, otherwise the quota usage icon will not be shown on Roundcube panel, the standard webmail client for zPanel. And, imap_quota can only be added to protocol imap but not other protocols like lmtp, etc. A sample of working dovecot.conf for zPanel with imap_quota and sieve setting. It should be noted that by adding a global mail_plugins setting – quota to this config file, i.e. declaring “mail_plugins quota” outside the protocol settings, in order to make the command: doveadm quota get -u [email user] work without error.

Config:

• zPanel  10.1.1
• Dovecot  2.0.9
• Postfix   2.6.6
• Roundcube  0.9.5

The post zPanel Mailbox Quota Limit appeared first on LarryLai.

after migrate from CentOS-3.5 server to FC5 for osCommerce-2.2, there are some issues mainly caused by imcompatibility w/ php5.

1. cannot display categories
2. cannot display admin
3. page manager cannot edit Extra Page

Solutions:

for 1.

• open /catalog/index.php
• change p.products_id = s.products_id
• to p2c.products_id = s.products_id

for 2.

• open /catalog/admin/includes/classes/upload.php
• comment out $this = null

for 3.

• check error_log file of apache
• add before array_merge($var1,..,$varN) the statement:
• if (!is_array()) { $var1 = array($var1) ;};
• :
• if (!is_array()) {$varN = array($varN);};

The post osCommerce php5 Issues appeared first on LarryLai.

The post java re-install appeared first on LarryLai.

mail.netvigator.com no longer provide smtp as outgoing server for mail client even connected directly to its ISP service.

Solution:

subscribe no-ip.com Alernate SMTP port (US$19.9 /yr. limited to 150 messages per day)

Tricks:

no-ip.com provide SMTP alternate port with SMTP AUTH but squirrelmail admin cannot handle SMTP AUTH (i couldn’t find a way to input the username and password for SMTP login).

The post Outgoing Mail SMTP appeared first on LarryLai.

Regarding reliability, i recalled that when i was serving Sun at the 1st yr., i.e. 1997-1998, there were frequent mailbox corruptions. Why? At that time, no support staff gave me an acceptable answer. Maybe i was not technical enough. Now i guess we were using an unreliable MTA (Mail-Transfer-Agent). Also, using NFS mounting the home directory requires extra reliability of MTA.

Anyway, i’m convinced that by common sense that every mail is saved as a separate file in maildir format is more reliable that saving every mail as appending to the mailbox file consisting of numerous mails especially when you think of having network connection interruption as saving a mail such that the whole file would be corrupted and then even a resend or rewrite could not fix the problem.

By using qmail, i am more acquainted with the 3 major components of mailing system: MTA, MDA and MUA. They must be working in harmony so as to receive incoming mails through SMTP by MTA, deliver to appropriate users by MDA and can be retrieved by mail client through MUA.

Also, i started to be awared that spammers can abuse open relays of SMTP servers to spread out unsolicited mails. However, not to open SMTP server or exactly relaying all mails to the SMTP server from the ISP is a “responsible” act.

One last important piece of note here is that the last line of the run script located at /var/qmail/supervise/qmail-smtpd/ has to be modified as below to make it work:

The post qmail replacing sendmail appeared first on LarryLai.

For the mail server, i successfully configured sendmail, dovecot (an imap server and client program). One important thing i’ve to remind myself is that after successfully receiving email to my larrylai.com account, i don’t know why the imap.alumni.ust.hk had a time out when i directly send mail through the server. Thus, i tried to configured sendmail.mc to use the smtp server – mail.netvigator.com. Another good pt. i think is that each mail i send out to the destination mail server will go through mail.netvigator.com, i.e. the receipient server will be connecting directly only to mail.netvigator.com.

Next is to install webmail server probably squirrelmail since it’s more popular i think.

The post Mail Server is Up appeared first on LarryLai.