On 17-Oct-2019 11:04 AM, Paul wrote:
Rene Lamontagne wrote:
On 2019-10-16 1:57 p.m., malone wrote:

A little off-topic, but Macrium is discussed quite often in this forum.

Every week or so I do a full Macrium backup onto an external USB
hard drive, then remove the drive from the computer and store it in
a safe place.

Recently I have, in addition, performed a Macrium backup to my
Network-Attached Storage device - a hard drive attached to my router
from which files can be shared by all the devices on my LAN.

I have to endure many power outages in this part of the world (rural
New Zealand). As all the computers on the network are laptops this
doesn't present too much of a problem, and if the outage is too long
a laptop will close down gracefully when the battery gets low. The
router (Asus DSL N55U), on the other hand, does not turn off
gracefully, but just stops the instant the power goes off. I've been
a bit worried about how this might affect the USB-attached NAS, but
so far there's been no problem. All the files, images, videos and
the like seem fine, although that may be because they were not being
used in any way at the instant of the power cut.

The Macrium image, on the other hand, is seriously affected. After
the power is reconnected I discover that the folder in which the
image was stored is completely empty. The 80GB image has completely
vanished! Furthermore, I am unable to delete that (now empty)
folder. The only remedy is to disconnect the NAS drive from the
router, reconnect it, then I'm able to delete that empty folder,
create a new folder and redo the Macrium backup. We've had two power
outages in the past week and exactly the same thing happened both
times. I lost the Macrium backup image located on the NAS.

The moral of this story must be that it's best not to have your
Macrium backup image connected, in any way, to an active network.
But, I'd be very interested to hear anyone's ideas on why the
Macrium image is affected so, but none of the other files on the NAS
are?

I do pretty much exactly as you do but I don't leave the backup drive
connected except while doing the backup, about 8 minutes once a week.
Here in Winnipeg we very seldom have a power outage, maybe once or
twice a year so this is not a problem
In your case I would invest in a UPS and keep the router and NAS on
it at all time, this gives you time to do a graceful shutdown.

Unfortunately I don't know why your Macrium Image files get clobbered
and not the other files, Smarter minds than mine will probably pitch
in with answers, Cheers and good luck.

Rene

Someone in another group, was having trouble doing "Safely Remove"
using the
tray icon. The root cause, was even though a Macrium Backup had
completed,
something called "TXF" was keeping some control files it used, open.
This prevented the disk from being Safely Removed. If you went to Disk
Management,
selected the device (row) in Disk Management, you could change the
disk status
to "Offline" state, and then the disk could be removed. "Offline" seems
to quietly defeat TXF.

This article explains what the capability is (atomic commit), but I don't
understand how that's important to Macrium -- why it matters.

https://en.wikipedia.org/wiki/Transactional_NTFS

Now, when the storage device is hosted by a router, chances are
that isn't a path that supports TXF. The volume may not have
the same file commit characteristics. Macrium at that point,
probably uses some fallback code it doesn't normally use,
to handle writes to whatever protocol that is (SAMBA? FTP?).

When you use a browser, and start downloading a large file,
if the browser dies, the "half-finished" file normally remains
there. And I don't think that uses TXF. So why is the Macrium
file disappearing ? Doesn't make a lot of sense. Unless
there is explicitly a mode that says "if the program dies,
delete that file".

Â*Â* Paul

Very interesting.

I had rebooted the originating laptop several times between creating the
image and the power outage. I would have thought that might have made
the Macrium image "safe".

And I suppose it may be dependent on the type of router?

Possibly a "proper" NAS configuration might not exhibit this behaviour.

But, for anyone who has a single backup image stored in a similar way,
they may like to be aware of this possibility. Losing your only backup
could be distressing in some circumstances.