Latest USB3 Memory Sticks and TRIM

[Chris Murphy]

On Aug 22, 2014, at 1:55 AM, John Austin <ja at 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