Bug 204641 - 10.2 UNMAP/TRIM not available on a zfs zpool that uses iSCSI disks, backed on a zpool file target

[Alexander Motin]

On 18.11.2015 02:28, Steven Hartland wrote:
> On 17/11/2015 22:08, Christopher Forgeron wrote:
>> I just submitted this as a bug:
>>
>> ( https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=204641 )
>>
>> ..but I thought I should bring it to the list's attention for more
>> exposure
>> - If that's a no-no, let me know, as I have a few others that are related
>> to this that I'd like to discuss.

> Having a quick flick through the code it looks like umap is now only
> supported on dev backed and not file backed.
> 
> I believe the following commit is the cause:
> https://svnweb.freebsd.org/base?view=revision&revision=279005
> 
> This was an MFC of:
> https://svnweb.freebsd.org/base?view=revision&revision=278672
> 
> I'm guessing this was an unintentional side effect mav?

As I have replied on the ticket: CTL never supported UNMAP on
file-backed LUNs due to lack of respective API for hole punching on
FreeBSD. At this time UNMAP works for ZVOLs in both device and file
modes and raw devices.

-- 
Alexander Motin