I tried to follow some online advice that says to use blkdiscard to issue discard requests to a block device...but strangely the util-linux package it said to check does not include this utility. I checked upstream and it's in the /util-linux-2.24/sys-utils/ folder, so for some reason it's not being built. Reproducible: Always
Please post your `emerge --info sys-apps/util-linux' output in a comment.
blkdiscard(8) was added in 2.23.