zvol clone diffs

[Dean E. Weimer]

On 2016-09-22 9:38 am, Slawa Olhovchenkov wrote:
> On Thu, Sep 22, 2016 at 04:56:53PM +0500, Eugene M. Zheganin wrote:
> 
>> Hi.
>> 
>> I should mention from the start that this is a question about an
>> engineering task, not a question about FreeBSD issue.
>> 
>> I have a set of zvol clones that I redistribute over iSCSI. Several
>> Windows VMs use these clones as disks via their embedded iSCSI
>> initiators (each clone represents a disk with an NTFS partition, is
>> imported as a "foreign" disk and functions just fine). From my 
>> opinion,
>> they should not have any need to do additional writes on these clones
>> (each VM should only read data, from my point of view). But zfs shows
>> they do, and sometimes they write a lot of data, so clearly facts and
>> expactations differ a lot - obviously I didn't take something into
>> accounting.
> 
> May be atime like on NTFS?
> 
> http://serverfault.com/questions/33932/how-do-you-disable-the-last-accessed-attribute-on-ntfs-windows

I would recommend using the windows Diskpart command and settings the 
volumes attribute to read only, this will force the NTFS volume to be 
readonly and shouldn't allow changes to be saved.

-- 
Thanks,
    Dean E. Weimer
    http://www.dweimer.net/