WAPBL and snapshots

[Louis Guillaume]

Hi,

I've been wanting to use `log' on my ffs filesystems for a long time,
but I keep getting scared away by this "caveat" in the wabpl(4) man page:

"File system snapshots (fss(4)) and quotas do not yet work with
WAPBL."

I use `dump -x' for backups. So essentially I'm SOL with regards to
journalling!

At least maybe until LVM comes into the stable branches with it's own
snapshot facility. But then LVM comes with a stiff warning...

"Snapshot feature is not fully implemented in LVM in NetBSD and
should not be used in production."

Aye! And there's no real indication that LVM plays nice with WAPBL
either (although I understand that LVM provides a separate layer of
abstraction that isn't a file system.)

I've taken to ignoring the comical "bug" in the fss(4) man page:

"This driver is experimental. Be sure you have a backup before
you use it."

It has worked fine for me for years. (Backups happen every night with
fss snapshots via `dump -x'.)

What it all boils down to is: What's the best approach to doing online
backups of a NetBSD system while incorporating journalled file systems?

So far I feel lucky that fss works for me despite its
"experimental"-ness; and luck isn't something I like to count on with
computers. Any advice would be most helpful. Thanks,

Louis

[Adam Hamsik]

Post by Louis Guillaume
Hi,
"File system snapshots (fss(4)) and quotas do not yet work with
WAPBL."
I use `dump -x' for backups. So essentially I'm SOL with regards to journalling!
At least maybe until LVM comes into the stable branches with it's own snapshot facility. But then LVM comes with a stiff warning...
"Snapshot feature is not fully implemented in LVM in NetBSD and
should not be used in production."

NetBSD LVM doesn't have any snapshot support.

Post by Louis Guillaume
Aye! And there's no real indication that LVM plays nice with WAPBL either (although I understand that LVM provides a separate layer of abstraction that isn't a file system.)

But it works pretty well with wapbl.


Regards

Adam.

[Juergen Hannken-Illjes]

Post by Louis Guillaume
Hi,
I've been wanting to use `log' on my ffs filesystems for a long time,
"File system snapshots (fss(4)) and quotas do not yet work with
WAPBL."

Snapshots should work with WAPBL enabled file systems. I use "dump -x"
on a logging NetBSD-5 machine two times a day. If I remember right
I had to increase the log size (tunefs).

Post by Louis Guillaume
I use `dump -x' for backups. So essentially I'm SOL with regards to
journalling!
At least maybe until LVM comes into the stable branches with it's own
snapshot facility. But then LVM comes with a stiff warning...
"Snapshot feature is not fully implemented in LVM in NetBSD and
should not be used in production."
Aye! And there's no real indication that LVM plays nice with WAPBL
either (although I understand that LVM provides a separate layer of
abstraction that isn't a file system.)
"This driver is experimental. Be sure you have a backup before
you use it."
It has worked fine for me for years. (Backups happen every night with
fss snapshots via `dump -x'.)

So may be it is the time to declare snapshots stable?

Post by Louis Guillaume
What it all boils down to is: What's the best approach to doing online
backups of a NetBSD system while incorporating journalled file systems?
So far I feel lucky that fss works for me despite its
"experimental"-ness; and luck isn't something I like to count on with
computers. Any advice would be most helpful. Thanks,
Louis

[Adam Hoka]

On Wed, 26 May 2010 22:27:31 -0400

Post by Louis Guillaume
Hi,
I've been wanting to use `log' on my ffs filesystems for a long time,
"File system snapshots (fss(4)) and quotas do not yet work with
WAPBL."
I use `dump -x' for backups. So essentially I'm SOL with regards to
journalling!

wfm