Re: [developer] ZFS and block devices

[Dave Osbourne]

Thanks for this!

That is the pointer I needed!!!

On 2016-09-23 02:25, Josh Paetzel wrote:
You can use dd. You may need to set the volmode depending on your 
platform to get access to the volume's device node. 
/dev/zvol//


Thanks,

Josh Paetzel

On Sep 22, 2016, at 2:28 PM, Dave Osbourne > wrote:



Hi,

I fear this may be wrong list... I googled, found and joined it...
let me know if I've got it wrong...

I have a situation where I want to do the equivalent of "dd" the
content of a zfs volume out to have effectively a copy of the raw device.

I've got zfs send > x.out and zfs receive < x.out working, but I'm
not sure how to interact with the zfs volume at a block level...
presumably there must be a way to get the equivalent of a

dd if= of=/copy-of-blockdevice.dd ?

such that if I needed to use copy-of-blockdevice.dd on another system
without ZFS I could write it do a physical drive?

I think I'm missing something fundamental.  I've read that zfs can do
blockIO (with volumes), but *I* can't seem to find out how to
interact with it on that level...

Regards,
Dave

*openzfs-developer* | Archives 
 
 
| Modify 
 
Your Subscription [Powered by Listbox] 






---
openzfs-developer
Archives: https://www.listbox.com/member/archive/274414/=now
RSS Feed: https://www.listbox.com/member/archive/rss/274414/28015062-cce53afa
Modify Your Subscription: 
https://www.listbox.com/member/?member_id=28015062&id_secret=28015062-f966d51c
Powered by Listbox: http://www.listbox.com

Re: [developer] ZFS and block devices

[Josh Paetzel]

You can use dd. You may need to set the volmode depending on your platform to 
get access to the volume's device node. /dev/zvol//

Thanks,

Josh Paetzel

> On Sep 22, 2016, at 2:28 PM, Dave Osbourne  wrote:
> 
> Hi,
> 
> I fear this may be wrong list... I googled, found and joined it... let me 
> know if I've got it wrong...
> 
> I have a situation where I want to do the equivalent of "dd" the content of a 
> zfs volume out to have effectively a copy of the raw device.
> 
> I've got zfs send > x.out and zfs receive < x.out working, but I'm not sure 
> how to interact with the zfs volume at a block level...  presumably there 
> must be a way to get the equivalent of a
> 
> dd if= of=/copy-of-blockdevice.dd ?
> 
> such that if I needed to use copy-of-blockdevice.dd on another system without 
> ZFS I could write it do a physical drive?
> 
> I think I'm missing something fundamental.  I've read that zfs can do blockIO 
> (with volumes), but *I* can't seem to find out how to interact with it on 
> that level...
> 
> Regards,
> Dave
> 



---
openzfs-developer
Archives: https://www.listbox.com/member/archive/274414/=now
RSS Feed: https://www.listbox.com/member/archive/rss/274414/28015062-cce53afa
Modify Your Subscription: 
https://www.listbox.com/member/?member_id=28015062&id_secret=28015062-f966d51c
Powered by Listbox: http://www.listbox.com