I believe discard support is only available since kernel 3.1. It'd be great if it was added to RHEL 6 - I'm using Fedora 18 on any machines that require it in the meantime. Cian. On 4 December 2013 21:59, Leon Fauster <leonfauster at googlemail.com> wrote: > Am 04.12.2013 um 19:20 schrieb Akemi Yagi <amyagi at gmail.com>: >> On Wed, Dec 4, 2013 at 9:20 AM, Leon Fauster <leonfauster at googlemail.com> wrote: >>> Am 04.12.2013 um 17:08 schrieb John Doe <jdmls at yahoo.com>: >>>> I just recently read a post about SSD triming (discard vs fstrim): >>>> >>>> http://www.howtogeek.com/176978/ubuntu-doesnt-trim-ssds-by-default-why-not-and-how-to-enable-it-yourself/So far I used discard on all my SSDs. >>>> Now I am wondering if it is really worth it to switch them all to a crontabed fstrim... >>>> Anyone made the switch yet? >>> >>> https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html-single/Storage_Administration_Guide/#idm34358800 >>> >>> "Red Hat recommends batch discard operations ..." (fstrim) >>> >> >> In addition to the RH doc referenced by LF, I found this web page useful: >> >> http://blog.neutrino.es/2013/howto-properly-activate-trim-for-your-ssd-on-linux-fstrim-lvm-and-dmcrypt/ > > > interesting article. it shows the passthrough of the discard option with > dm-crypt involved. rhel seems to not provide such "dm-crypt/trim" support. > > https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/ch-ssd.html#ssddeploy > > "The only DM targets that do not support discards are dm-snapshot, dm-crypt, and dm-raid45." > > maybe with the next minor release? > > -- > LF > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos