Speeding up slow disks with SSD caching
Hard disks are inexpensive, and they have huge capacities, but they are also slow. Solid state disks (SSDs) are fast, but smaller and more expensive. If you combine the advantages of a hard disk with an SSD-based cache, you pick up a large performance gain at a reasonable cost.
An application generally does not want all the data at once; most of the data is in the state of being ignored most of the time. Caching lets you move the most frequently requested data to an exclusive, fast medium and leave the less-frequently accessed data on the cheaper but slower background medium.
The Linux environment has several tools that provide the necessary software to support hard-disk caching. Does it help to use an SSD-based flash drive as a cache for a traditional hard disk? We decided to find out. This article explores the possibilities for caching with the Linux caching tools Enhance IO and dm-cache. If you are new to the topic of caching, and you would like some additional information on choices you might have to make, see the boxes titled "A Little Cache Theory" and "How Flash Works."
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Fedora Continues 32-Bit Support
In a move that should come as a relief to some portions of the Linux community, Fedora will continue supporting 32-bit architecture.
-
Linux Kernel 6.17 Drops bcachefs
After a clash over some late fixes and disagreements between bcachefs's lead developer and Linus Torvalds, bachefs is out.
-
ONLYOFFICE v9 Embraces AI
Like nearly all office suites on the market (except LibreOffice), ONLYOFFICE has decided to go the AI route.
-
Two Local Privilege Escalation Flaws Discovered in Linux
Qualys researchers have discovered two local privilege escalation vulnerabilities that allow hackers to gain root privileges on major Linux distributions.
-
New TUXEDO InfinityBook Pro Powered by AMD Ryzen AI 300
The TUXEDO InfinityBook Pro 14 Gen10 offers serious power that is ready for your business, development, or entertainment needs.
-
Danish Ministry of Digital Affairs Transitions to Linux
Another major organization has decided to kick Microsoft Windows and Office to the curb in favor of Linux.
-
Linux Mint 20 Reaches EOL
With Linux Mint 20 at its end of life, the time has arrived to upgrade to Linux Mint 22.
-
TuxCare Announces Support for AlmaLinux 9.2
Thanks to TuxCare, AlmaLinux 9.2 (and soon version 9.6) now enjoys years of ongoing patching and compliance.
-
Go-Based Botnet Attacking IoT Devices
Using an SSH credential brute-force attack, the Go-based PumaBot is exploiting IoT devices everywhere.
-
Plasma 6.5 Promises Better Memory Optimization
With the stable Plasma 6.4 on the horizon, KDE has a few new tricks up its sleeve for Plasma 6.5.