Mythbusting Linux

[michael-piziak]

Interesting video here.

https://www.youtube.com/watch?v=y_lhqg_p21k

The 2 most intriguing things to me is the maleware/virus part and the defrag part. Clamtk is a free anti-virus/anti-malware program we can use. About the defrag part, does Ubuntu defrag in the background? I see there is a program in the software center for sale ($7.99) called HDD Ranger that is a defrag program for Ubuntu - is this needed ?

[MartyBuntu]

Here's a little salt to be taken with much of what Matthew Moore disseminates...

http://snowclearancedirect.com/_downloads/1_1_Bulk_Bag_-_Rock_Salt.JPG

[grahammechanical]

The Ext4 file system is default on Ubuntu


Extents
Extents (https://en.wikipedia.org/wiki/Extent_%28file_systems%29) replace the traditional block mapping (https://en.wikipedia.org/wiki/Block_%28data_storage%29) scheme used by ext2 and ext3. An extent is a range of contiguous physical blocks, improving large file performance and reducing fragmentation.



Persistent pre-allocation
ext4 can pre-allocate on-disk space for a file. To do this on most file systems, zeros would be written to the file when created. In ext4 (and some other files systems such as XFS (https://en.wikipedia.org/wiki/XFS)) fallocate(), a new system call in the Linux kernel, can be used. The allocated space would be guaranteed and likely contiguous. This situation has applications for media streaming and databases.



Delayed allocation
ext4 uses a performance technique called allocate-on-flush (https://en.wikipedia.org/wiki/Allocate-on-flush) also known as delayed allocation. That is, ext4 delays block allocation until data is flushed to disk. (In contrast, some file systems allocate blocks immediately, even when the data goes into a write cache.) Delayed allocation improves performance and reduces fragmentation (https://en.wikipedia.org/wiki/File_system_fragmentation) by effectively allocating larger amounts of data at a time.


https://en.wikipedia.org/wiki/Ext4

Regards.

[kostkon]

Here's a little salt to be taken with much of what Matthew Moore disseminates...

http://snowclearancedirect.com/_downloads/1_1_Bulk_Bag_-_Rock_Salt.JPG
Even that is not enough.

He got the views though.