TRIM on XFS

[Jeffrey Hundstad]

On 10/10/2011 03:28 PM, Greg Freemyer wrote:
> fitrim is the batch mode.
>
> To enable realtime discard, add --discard to your mount options.
>
> Documented athttp://lxr.linux.no/#linux+v3.0.4/Documentation/filesystems/xfs.txt
>
> To invoke batch mode, simply use fstrim from user space.

Hello,

I'm also trying to use FITRIM on a simple XFS partition on a spinning 
magnetic hard drive (remember those).  I haven't had much luck.  I'm 
doing this just to get used to the commands when using this against a 
thinly provisioned disk.  I have no idea if this should work in this 
configuration.

On a Debian system with Linux 3.0.0-2-amd64 when I issue:
# fstrim /

I receive:
fstrim: /: FITRIM ioctl failed: Operation not supported

With an strace this looks like:
open("/", O_RDONLY)                     = 3
ioctl(3, 0xc0185879, 0x7fff4ea851b0)    = -1 EOPNOTSUPP (Operation not 
supported)

My fstrim is from util-linux-2.19.1-5

I'd be happy to try to diagnose this further if people are interested.  
Any suggestions where I should start would be much appreciated.

-- 
Jeffrey Hundstad