zfs discuss - Jan 2008 - How to do "zfs send" to remote tape drive without intermediate file?

Hi list,

I''d like to be able to store zfs filesystems on a tape drive that is
attached to
another Solaris U4 x86 server. The idea is to use "zfs send" together
with tar in order to get the list of the filesystems'' snapshots stored
on a tape and be able to perform a restore operation later. It''s pretty
nice to use tar to get a content of the tape in human-readable form.

How can I do it in-one-command without intermediate file? 

The file ifself can be done using "zfs send tank/filesystem at snapshot
> /path/to/filesystem_snapshot.zfs" ? But it''s painfull to
reserve pretty large amount if disk space to store intermidiate .zfs file..

Of course, I can write to remote type using ssh using the command below but
I''d lile to see some kind of meaningful names on the tape:

# zfs send tank/filesystem at snapshot | ssh remote_server "cat >
/dev/rmt/0bn"

Thanks,
Sergey
 
 
This message posted from opensolaris.org

> Hi list,
>
> I''d like to be able to store zfs filesystems on a tape drive that
is
> attached to another Solaris U4 x86 server. The idea is to use "zfs
send"
> together with tar in order to get the list of the filesystems''
snapshots
> stored on a tape and be able to perform a restore operation later.
It''s
> pretty nice to use tar to get a content of the tape in human-readable 
> form.
I don''t think you want to do this.  Unless there has been a change of 
heart you can''t rely on zfs receive accepting the zfs send from an old 
dump file.  It is only guaranteed to work for the same version of zfs/the 
zfs tools.

If there has been a change of heart then I want to know about it.
> How can I do it in-one-command without intermediate file?
>
> The file ifself can be done using "zfs send tank/filesystem at
snapshot >
> /path/to/filesystem_snapshot.zfs" ? But it''s painfull to
reserve pretty
> large amount if disk space to store intermidiate .zfs file..
Bearing in mind that I don''t think you want to do this..

zfs send tank/filesystem at snapshot | ssh remote_server \(
command_to_label_tape \; dd of=/dev/rmt/0bn \)

> Of course, I can write to remote type using ssh using the command below 
> but I''d lile to see some kind of meaningful names on the tape:
>
> # zfs send tank/filesystem at snapshot | ssh remote_server "cat > 
> /dev/rmt/0bn"
What kind of name do you want?  Where do you want it.  There are loads of 
ways.  Starting from

echo "tank/filesystem at snapshot `date`" > /dev/rmt/0bn

upwards.

> Thanks, Sergey
Julian
-- 
Julian King
Computer Officer, University of Cambridge, Unix Support

Sergey wrote:
> Hi list,
>
> I''d like to be able to store zfs filesystems on a tape drive that
is attached to
> another Solaris U4 x86 server. The idea is to use "zfs send"
together with tar in order to get the list of the filesystems''
snapshots stored on a tape and be able to perform a restore operation later.
It''s pretty nice to use tar to get a content of the tape in
human-readable form.
>
> How can I do it in-one-command without intermediate file? 
>
> The file ifself can be done using "zfs send tank/filesystem at
snapshot > /path/to/filesystem_snapshot.zfs" ? But it''s
painfull to reserve pretty large amount if disk space to store intermidiate .zfs
file..
>
> Of course, I can write to remote type using ssh using the command below but
I''d lile to see some kind of meaningful names on the tape:
>
> # zfs send tank/filesystem at snapshot | ssh remote_server "cat >
/dev/rmt/0bn"
>   
close.  mt(1) is the command you want rather than cat.
 -- richard

Richard Elling wrote:
> Sergey wrote:
>   
>> Hi list,
>>
>> I''d like to be able to store zfs filesystems on a tape drive
that is attached to
>> another Solaris U4 x86 server. The idea is to use "zfs send"
together with tar in order to get the list of the filesystems''
snapshots stored on a tape and be able to perform a restore operation later.
It''s pretty nice to use tar to get a content of the tape in
human-readable form.
>>
>> How can I do it in-one-command without intermediate file? 
>>
>> The file ifself can be done using "zfs send tank/filesystem at
snapshot > /path/to/filesystem_snapshot.zfs" ? But it''s
painfull to reserve pretty large amount if disk space to store intermidiate .zfs
file..
>>
>> Of course, I can write to remote type using ssh using the command below
but I''d lile to see some kind of meaningful names on the tape:
>>
>> # zfs send tank/filesystem at snapshot | ssh remote_server "cat
> /dev/rmt/0bn"
>>   
>>     
>
> close.  mt(1) is the command you want rather than cat.
>   
I sent too soon, mt(1) for managing tape files.  It is also usually better
to use dd as JP suggests because you can match the block size, which
is needed for efficiency in some cases.
 -- richard
>  -- richard
>
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