Modification of files connected by hardlinks

Hello everybody,
in the course there's a sentence:
"Hard links point to an inode. All hard linked files have to be on the same filesystem. Changing the content of a hard linked file in one place may not change it in other places."
My question is: why may not?
When I create a hard link, I point to exactly the same inode like the source file, which also is visible on the screen attached to the course (see below, very first column):
All external sources I read say the same: it's a mirror and all changes made are "synchronized": https://cbtnuggets.com/blog/certifications/open-source/linux-hard-links-versus-soft-links-explained, https://ostechnix.com/explaining-soft-link-and-hard-link-in-linux-with-examples/
Can I consider the may not as a mistake in the course?
Best Answer
-
Because there is software that when it wants to make a modification to a file, it works on a modified copy, removes the old one and copies the new edition to the old location, thus breaking the hard link. This can indeed be bad software and is less common today than it used to be (I remember day-to-day editors that did this.) But it can happen and can lead to catastrophic screw ups. So whatever you read on the Internet, this is something I've learned through experience not to ignore. In fact, a simple "cp" that overwrites the file can break the link.
1
Answers
-
Thanks for the explanation, now I got it.
0
Categories
- 9.1K All Categories
- 15 LFX Mentorship
- 68 LFX Mentorship: Linux Kernel
- 380 Linux Foundation Boot Camps
- 233 Cloud Engineer Boot Camp
- 75 Advanced Cloud Engineer Boot Camp
- 30 DevOps Engineer Boot Camp
- 9 Cloud Native Developer Boot Camp
- 974 Training Courses
- 15 LFC110 Class Forum
- 16 LFD102 Class Forum
- 106 LFD103 Class Forum
- 5 LFD121 Class Forum
- 56 LFD201 Class Forum
- 1 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum
- 19 LFD254 Class Forum
- 450 LFD259 Class Forum
- 90 LFD272 Class Forum
- 1 LFD272-JP クラス フォーラム
- 16 LFS200 Class Forum
- 712 LFS201 Class Forum
- LFS201-JP クラス フォーラム
- 282 LFS211 Class Forum
- 50 LFS216 Class Forum
- 27 LFS241 Class Forum
- 28 LFS242 Class Forum
- 19 LFS243 Class Forum
- 6 LFS244 Class Forum
- 12 LFS250 Class Forum
- LFS250-JP クラス フォーラム
- 113 LFS253 Class Forum
- 813 LFS258 Class Forum
- 8 LFS258-JP クラス フォーラム
- 54 LFS260 Class Forum
- 81 LFS261 Class Forum
- 18 LFS262 Class Forum
- 76 LFS263 Class Forum
- 14 LFS264 Class Forum
- 10 LFS266 Class Forum
- 10 LFS267 Class Forum
- 9 LFS268 Class Forum
- 6 LFS269 Class Forum
- 182 LFS272 Class Forum
- 1 LFS272-JP クラス フォーラム
- 191 LFW211 Class Forum
- 114 LFW212 Class Forum
- 880 Hardware
- 207 Drivers
- 74 I/O Devices
- 44 Monitors
- 115 Multimedia
- 205 Networking
- 98 Printers & Scanners
- 82 Storage
- 730 Linux Distributions
- 85 Debian
- 64 Fedora
- 12 Linux Mint
- 13 Mageia
- 22 openSUSE
- 127 Red Hat Enterprise
- 33 Slackware
- 13 SUSE Enterprise
- 349 Ubuntu
- 450 Linux System Administration
- 33 Cloud Computing
- 64 Command Line/Scripting
- Github systems admin projects
- 89 Linux Security
- 76 Network Management
- 105 System Management
- 45 Web Management
- 51 Mobile Computing
- 19 Android
- 19 Development
- 1.2K New to Linux
- 1.1K Getting Started with Linux
- 501 Off Topic
- 121 Introductions
- 193 Small Talk
- 19 Study Material
- 756 Programming and Development
- 243 Kernel Development
- 479 Software Development
- 903 Software
- 247 Applications
- 178 Command Line
- 2 Compiling/Installing
- 73 Games
- 314 Installation
- 26 All In Program
- 26 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)