zfs discuss - Apr 2009 - What can I do to shorten the long awkward names of snapshots?

How can I make zfs give some shorter kind of names to the auto snapshots
it takes. 

I''d like to alter the date string and shorten like this:

  zfs-auto-snap:frequent-2009-04-15-16:30

Would become:
  a:freq-041509_1630

That''s less than 1/2 the 40 characters the auto process generates.

I find these long names awkward to deal with.  Like when ssh''d in and
in a console terminal, if you run a long ls, those names are going to
wrap and become confusing to look at for no good reason.

Where can I adjust this naming mechanism... including date.. maybe a
separate mechanism.

Hi Harry,

On Wed, 2009-04-15 at 16:59 -0500, Harry Putnam wrote:
> How can I make zfs give some shorter kind of names to the auto snapshots
> it takes.
> 
> I''d like to alter the date string and shorten like this:
> 
>   zfs-auto-snap:frequent-2009-04-15-16:30
> Would become:
>   a:freq-041509_1630
> 
> That''s less than 1/2 the 40 characters the auto process generates.
If you want to change it, you''ll need to edit some hardcoded values in
the method script and tweak a few SMF values.

In /lib/svc/method/zfs-auto-snapshot, change

* the $PREFIX variable
* the $SEP variable
* the $DATE variable

and in the various SMF instances, change the "zfs/label" property, eg:

timf at igyo[72] svcprop -p zfs/label auto-snapshot
svc:/system/filesystem/zfs/auto-snapshot:weekly/:properties/zfs/label astring
weekly
svc:/system/filesystem/zfs/auto-snapshot:monthly/:properties/zfs/label astring
monthly
svc:/system/filesystem/zfs/auto-snapshot:hourly/:properties/zfs/label astring
hourly
svc:/system/filesystem/zfs/auto-snapshot:frequent/:properties/zfs/label astring
frequent
svc:/system/filesystem/zfs/auto-snapshot:daily/:properties/zfs/label astring
daily

I''m not 100% sure what would happen on upgrade if you change the method
script, so that might be worth keeping in mind should you choose to do
that.

It''s worth pointing out, that should you choose a pattern that happens
to match an existing snapshot, that snapshot is liable to be destroyed
when the service recycles old snapshots, so take care!

[ we could potentially fix that, now that snapshots have their own
user-properties, by adding a user-property to every auto-snapshot that
was taken, and taking care to only destroy those ones, but we''re not
there yet ]

Hope this helps,

	cheers,
			tim

Tim Foster <Tim.Foster at Sun.COM> writes:
>
> Hope this helps,
Yes and a good bunch of info there... thanks.

Looks way to complicated just sooth line wrapping in some
circumstances.   Thanks for the walk thru though.

On Wed, 15 Apr 2009, Harry Putnam wrote:

> Would become:
>  a:freq-041509_1630
Can I suggest perhaps something inspired by the old convention for DNS 
serials, along the lines of fyyyymmddtt? Like:

a:f200904151630

This makes things easier to sort and lines up in a tidy manner.


-- 
Andre van Eyssen.
mail: andre at purplecow.org          jabber: andre at interact.purplecow.org
purplecow.org: UNIX for the masses http://www2.purplecow.org
purplecow.org: PCOWpix             http://pix.purplecow.org

The cool thing about the way Tim has built the service is that you can
edit the variable values in the method script to make snapshot titles
pretty much whatever you want.  I think he made a good compromise
choice between simplicity and clarity in the current titling system.

Remember that the Time Slider snapshot viewer essentially makes this
transparent to a the end user.  And you can make use of Time Slider
remotely using ssh -X hostname and then nautilus --no-desktop.



On Wed, Apr 15, 2009 at 8:32 PM, Andre van Eyssen <andre at purplecow.org>
wrote:
> On Wed, 15 Apr 2009, Harry Putnam wrote:
>
>
>> Would become:
>> ?a:freq-041509_1630
>
> Can I suggest perhaps something inspired by the old convention for DNS
> serials, along the lines of fyyyymmddtt? Like:
>
> a:f200904151630
>
> This makes things easier to sort and lines up in a tidy manner.
>
>
> --
> Andre van Eyssen.
> mail: andre at purplecow.org ? ? ? ? ?jabber: andre at
interact.purplecow.org
> purplecow.org: UNIX for the masses http://www2.purplecow.org
> purplecow.org: PCOWpix ? ? ? ? ? ? http://pix.purplecow.org
>
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