On 2018-10-29 15:12, Tim Darby wrote:
This is an issue I've reported:
http://bugs.dragonflybsd.org/issues/2915
My way around this is to create the new master and use cpdup to copy
the PFS slave to it.
Tim
Hi, Tim.
Thanks for your reply.
Your problem does look similar to mine. But I now think it might not be
a bug: latest transactions might not be commited.
Reading through the manual once more I noticed there is a command
"hammer synctid" which syncs the PFS and gives you the TID that you
might use to check that mirror-copy/stream reached it.
I will experiment with it a bit more and let you know if the problem
resolves.
--
Aleksej Lebedev
On Mon, Oct 29, 2018 at 6:22 AM Aleksej Lebedev <[email protected]> wrote:
Hi!
Recently my 5T hard drive broke. It contained among other things a
master PFS that was backed up to a remote host.
I replaced broken hard drive, formatted it and run hammer mirror-copy
from the remote pfs. After that I upgraded the freshly copied PFS to
master
and now I can't set up the backup process again. The command "hammer
mirror-stream" simply doesn't do anything.
Both my new master PFS and old backup seem to work OK and I can even
mirror-stream from them to other places. But I can't mirror-stream
from
master to slave.
I checked sync-end-tid on both of them and noticed that for some
reason
the TID of my new master is a bit behind the one on my slave.
So I guess I somehow a few changes from my backup were not commited to
my new harddrive. The problem is I already upgraded this PFS to master
and even made some changes on it (just for testing, I don't mind
loosing
them).
I realize that I can easily delete the master PFS, re-mirror it again
from my backup and make sure it has the same sync-end-tid before
upgrading it to master, but I would like to avoid it because the PFS
is
very large.
My question: is it possible to roll-back a PFS (master or slave) a few
transactions back?
I noticed that "hammer pfs-update" allows to simply change
sync-end-tid,
but since I don't understand what it is made for I am in doubt.
Especially because the man page states "Manually modifying this field
is
dangerous and can result in a broken mirror."
Is there a way to roll-back a PFS or I have to re-mirror it from my
backup again?
(I also now that I can do a local mirror-stream from my new master to
separate PFS, stop it right before the end and then finish mirroring
from my backup, but I it requires a lot of copying anyway, though
local
is better than remote, which I would like to avoid.)
--
Aleksej Lebedev
