Re: Disabling snapshot symlinks during manual snapshot

[Siju George <sgeorge.ml@xxxxxxxxx>]

On Wed, Apr 21, 2010 at 11:04 PM, Matthew Dillon
<dillon@apollo.backplane.com> wrote:
>
>    Make sure your cron job runs the rsync under a lockf.  e.g.:
>
>    */5 * * * *  lockf -kt 0 /root/adm/.lock1 rsync ....
>
>    Otherwise any long syncs or other issues can cause rsyncs to build
>    up.
>

Oh yes you taught me that trick for running the script checking and
restarting mirror-stream process.
I use it now where ever I can :-)


> :I shared /Backup1/www-5mbak read only using samba and the developers
> :can now get 5mis backup of any file  for 2 days.
>
>    I'm not I understand.  So the snapshots in this subdirectory are
>    softlinks using absolute paths to the original directory with
>    an @@ extension?  Otherwise they might not be able to access the
>    snapshot.
>

Yes the snapshot Directory is set to

hammer snapshot /Backup1/www-5mbak/www-hot /Backup1/www-5mbak

So in the snapshot Directory you get snapshots such as

dfly-bkpsrv# pwd
/Backup1/www-5mbak
dfly-bkpsrv# ls -l
total 0
lrwxr-xr-x  1 root  wheel  47 Apr 21 11:03 snap-20100421-1103 ->
/Backup1/www-5mbak/www-hot/@@0x00000001cfb1fad0
lrwxr-xr-x  1 root  wheel  47 Apr 21 11:10 snap-20100421-1110 ->
/Backup1/www-5mbak/www-hot/@@0x00000001cfb1fcb0

The pfs is mounted inside the snapshot Directory.

For a MS Windows user it will look like the actual pic below.

http://picasaweb.google.com/sgeorge.ml/OpenBSDDesktop#5462824618389365522

Clicking on the snapshot Directory they can get the snapshot contents :-)


> :To give them a daily backup access the same way I guess i will have to
> :configure a mirror and configure daily snapshots for them right?
>
>    You can use the same mirror and just pick out or generate daily
>    softlinks.  You don't need to configure another one.  I'm not
>    entirely sure how you'd make sure the softlinks track the actual
>    snapshots in terms of snapshot retirement as the hammer utility
>    only tracks one snapshot directory.
>

I plan to configure a Slave mirror on another Disk for this PFS. I can
then snapshot it Daily and Share the Snapshot Links Directory using
another Samba Share.

Suppose I configure the prune-min period of the Slave pfs as 2d.
Will I be able to generate 5 min snapshots from it of the previous day
from it should I lose the Master PFS Disk?

I mean if you have the history retained for 2 days can you create
snapshots of the filesystem of a previous time?

> :I might get rid of backuppc if I can store at least 2 years worth of
> :Daily backups like this.
>
>    You always want a backup on some other machine somewhere, no matter
>    what.
>

OK then :-)

> :Is there any way to find the space used by a single PFS and the space
> :used by its snapshots ?
>
>    No, someone would have to write a feature in the hammer utility to
>    calculate it.
>
>

Alright Thanks :-)