Create a RAM disk in Linux

https://www.jamescoyle.net/how-to/943-create-a-ram-disk-in-linux

There are two main types of RAM disk which can be used in Linux and each have their own benefits and weaknesses:

• ramfs
• tmpfs

https://www.jamescoyle.net/knowledge/951-the-difference-between-a-tmpfs-and-ramfs-ram-disk

tmpfs vs. ramfs

The two main RAM based file system types in Linux are tmpfs and ramfs. ramfs is the older file system type and is largely replaced in most scenarios by tmpfs.

When does /tmp get cleared?

http://serverfault.com/questions/377348/when-does-tmp-get-cleared

That depends on your distribution. On some system, it's deleted only when booted, others have cronjobs running deleting items older than n hours.

• On Debian-like systems: on boot (the rules are defined in /etc/default/rcS).
• On RedHat-like systems: by age (RHEL6 it was /etc/cron.daily/tmpwatch ; RHEL7 and RedHat-like with systemd it's configured in /usr/lib/tmpfiles.d/tmp.conf, called by systemd-tmpfiles-clean.service).
• On Gentoo /etc/conf.d/bootmisc.

How to remove svn:needs-lock from the folder level ?

http://stackoverflow.com/questions/1536824/subversion-how-to-remove-property-on-commit

Example:

> svn propdel svn:needs-lock -R -q [folder_name]
> svn commit [folder_name] -m "Removed needs-lock"

Learning Spark/Hadoop

http://www.cloudera.com/developers/featured-video.html

https://bigdatauniversity.com/

https://www.youtube.com/watch?v=K14plpZgy_c (data: https://data.sfgov.org)