On Aug 22, 2014, at 1:55 AM, John Austin ja@jaa.org.uk wrote:
Hi I have a Corsair Flash Voyager GTX USB3 memory stick which is advertised as supporting TRIM.
I assume there are several other manufacturers with similar devices
My device is working well (ext4) and is very fast but does not appear to respond to the TRIM command even though hdparm suggests it should
I have found the same problem referenced here https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1336541 but following the kernel link I am not totally convinced things are happening upstream
Should I bugzilla this against Fedora this or just wait?
You could strace the mount and see if it's checking
/sys/block/sdb/queue/rotational
This is commonly done to see if the device supports trim/discard first. If it's a 1 then it may be a udev thing.
Likewise you can strace mkfs.ext4 which I think defaults to -E discard if the value for ../rotational is 0. I know this is the case for mkfs.btrfs. See thread "zeroing out part of an SDcard" for some things I found relating to SD Cards.
Chris Murphy