Can I enable discards on a LUKS-encrypted ssd drive in RHEL6 (and do I need to)?

Posted by Dan Nestor on Super User See other posts from Super User or by Dan Nestor
Published on 2013-10-27T20:11:33Z Indexed on 2013/10/27 21:56 UTC
Read the original article Hit count: 275

Filed under:

linux

|

Performance

|

ssd

|

rhel

|

trim

I have a RHEL 6.4 workstation, running on a LUKS-encrypted LV residing on a SSD. I found RedHat documentation stating that dm_crypt does not currently support TRIM passthrough, however I also found other sources that state the opposite (albeit for other distributions) and even that discards are not needed for recent SSD drives which use some sort of automatic garbage collection. So:

1) Can I enable TRIM/discards with my setup?

2) Do I need to, for optimal disk performance?

Thanks for your thoughts.

© Super User or respective owner

Related posts about linux

apt-get install and update fail

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've got a problem with apt-get update and apt-get install ... commands . every time update or installing fails and errors are : Get:1 http://dl.google.com stable Release.gpg [198B] Ign http://dl.google.com/linux/chrome/deb/ stable/main Translation-en_US Get:2 http://dl… >>> More
kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
Build-Essentials installation failing

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am having trouble accessing the several critical header files that show to be a part of the build process. The "Ubuntu Software Center" shows "Build Essentials" as installed: Next I did the following two commands, which did not improve the problem: ~$ sudo apt-get install build-essential [sudo]… >>> More
Updating Debian kernel

as seen on Super User - Search for 'Super User'
I'm trying to update my Debian machine to 2.6.32-46 (which is the new stable). However, after doing apt-get update my apt-cache search linux-image shows me: linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486 linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem linux-headers-2… >>> More
Serial connection over a single USB cable (Windows to linux, or linux to linux)

as seen on Server Fault - Search for 'Server Fault'
I'm helping out with a project for an embedded device that only has USB and no serial. This device is running Linux. These days, when we need to connect to a serial port on a device we typically use a USB to serial adapter (on something like a phone system or a load balancing device, etc). I would… >>> More

Related posts about Performance

Improving VPN performance - stronger encryption = more performance?

as seen on Server Fault - Search for 'Server Fault'
I have a site-to-site VPN set up with two SonicWall's (a TZ170 and a Pro1260). It was suggested to me that turning off encryption (so the VPN is tunneling only) would improve performance. (I'm not concerned with security, because the VPN is running over a trusted line.) Using FTP and HTTP transfers… >>> More
Inaccurate performance counter timer values in Windows Performance Monitor

as seen on Stack Overflow - Search for 'Stack Overflow'
I am implementing instrumentation within an application and have encountered an issue where the value that is displayed in Windows Performance Monitor from a PerformanceCounter is incongruent with the value that is recorded. I am using a Stopwatch to record the duration of a method execution, then… >>> More
Excel-based Performance Reviews transformed into Web Application for Performance Management

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
HR TMS provides enterprise talent management solutions for healthcare, retail and corporate customers, focusing on performance management, compensation management and succession planning. As the competency of nurses and other healthcare workers is critical, the government, via the Joint Commission… >>> More
How to save a perfmon Performance Counter as a textfile (Reliability and Performance Monitor Version

as seen on Server Fault - Search for 'Server Fault'
Now the file gets saved as blg, but I would like a txt versin to import in Excel. >>> More
SQLAuthority News – A Successful Performance Tuning Seminar at Pune – Dec 4-5, 2010

as seen on SQL Authority - Search for 'SQL Authority'
This is report to my third of very successful seminar event on SQL Server Performance Tuning. SQL Server Performance Tuning Seminar in Colombo was oversubscribed with total of 35 attendees. You can read the details over here SQLAuthority News – SQL Server Performance Optimizations Seminar – Grand… >>> More