Re: btrsf

[Steffen Nurpmeso <steffen%sdaoden.eu@localhost>]

Benny Siegert wrote in
 <CAN+FjHPkaB-rjqDB0O_+hD6tFC-ER=Ox9hncKKHhKOC6pBc_Hg%mail.gmail.com@localhost>:
 |On Wed, Oct 19, 2022 at 1:55 PM Todd Gruhn <tgruhn2%gmail.com@localhost> wrote:

Man did i get spam mails after sending the message.

 |> IS BTRFS in pkgsrc? Where?
 |
 |It's a Linux thing. On NetBSD, there is ZFS, which does the same thing
 |except it doesn't lose your data :)

ZFS is much superior and much bigger.
I think in FreeBSD they could end up with only one program for
mounting, sharing, creating, etc., filesystems.  Booting.
It is not at all like this with BTRFS.

  (But you better adhere

    . "i have found a ML message from 2013
    https://www.spinics.net/lists/linux-btrfs/msg25940.html and
    i will use cache=writeback for my qemu instances as long as
    i live on BTRFS.  Thanks."

^ I also set do-not-copy-on-write on VM directories.
So except one VM image that had a messed up last block because of
this caching issue, which they should document prominently
i think, but do not, i have not lost any data yet.

    . receiving snapshots that do not fit the device might be
    tracked as successful:

     < multicore> stenur: "btrfs sub list -R" check for the
     received uuid, if it's there then the send should've
     completed
     < multicore> stenur: if you don't see received uuid then the
     snap wasn't received successfully
     < stenur> multicore: ..ok.. hm; what is shown for
      non-successfully received snapshots?  For "non-received" aka
      "local" snapshots it seems to be -
    < darkling> stenur: Then the received_uuid field will be
    empty.
^ I do not know whether they fixed _that_.  (That is, their source
code said it _cannot_ be empty, it is set to "-" then, and then
you cannot differentiate in between a normal local snapshot and
a bogus failed received one.)

    . Actually shrinking required many rounds regardless of defrag
    and whatever else i tried, until i ended where it should have
    ended at first.  Some stale metadata seemed to be in the way.
  )

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)