Feature changed by: Peter Simons (psimons) Feature #321838, revision 7 Title: Support TRIM/discard mode when installing to SSD openSUSE Distribution: Rejected by Tomáš Chvátal (scarabeus_iv) reject reason: See last comment. Priority Requester: Desirable Requested by: Peter Simons (psimons) Partner organization: openSUSE.org Description: While installing Tumbleweed (and Leap 42.2) with an encrypted disk, there is no way to enable TRIM/discard mode the for the underlying SSD. I *can* specify the "discard" mount option in the expert partitioner mode, but I cannot add the necessary "--allow-discards" option to the call to "cryptsetup" anywhere. Only *after* booting the newly installed system it's possible to enable that feature, and even then I have to manually edit /etc/crypttab to do it. Business case (Partner benefit): openSUSE.org: TRIM mode allows modern SSDs to operate faster than they can without it. There are security implications when combined with LUKS encryption, but having that ability as an optional feature sure is desirable (and many other distributions support it, too). Discussion: #1: Martin Pluskal (pluskalm) (2017-06-12 17:39:51) This behaviour is afaik intentional - enabling discard as mount option/or with luks can lead to premature degradation of many ssd devices - on other hand fstrim from util linux has service/timer which will trigger it periodically which is in most cases sufficient and safe. #2: Peter Simons (psimons) (2017-06-12 19:58:56) (reply to #1) Actually, it's the other way round. TRIM was invented to *prevent* SSD degradation and to improve both longevity and performance of SSD drives, i.e. by combating Write Amplification. https://en.wikipedia.org/wiki/Write_amplification has some details. Running fstrim via cron alleviates these issues to some degree, but it's certainly not the same thing as using TRIM continuously. It feels really weird that openSUSE does not take advantage of these features which have been around (and are standard practice in other distributions) for several years now. #3: Martin Pluskal (pluskalm) (2017-06-12 20:25:01) (reply to #2) Intention and implementation sadly differ - there are plenty of ssd drives with faulty trim implementations see [1][2] and it is often recommended against enabling this unless one is sure that his drive is not among faulty ones. 1. https://forums.freebsd.org/threads/56951/#post-328912 2. https://wiki.debian.org/SSDOptimization + #4: Peter Simons (psimons) (2017-06-12 22:41:17) (reply to #3) + Yes, I am sure SSDs with broken firmware exist. That is a compelling + reason to not enable TRIM features unconditionally. Instead, users + should have the option to enable use of TRIM if they want to. The + reason I created this FATE entry is because openSUSE's installer does + not allow its users to do that. -- openSUSE Feature: https://features.opensuse.org/321838