The network backup was convenient because I did not need to care when it was updated. I am always connected to network by WiFi. And it used to work. With USB disk I need to connect it from time for making backups. This extra care was not needed before.
The Airport Extreem is a good idea. Thank you. I only have Airport Express, which would not accept a USB disk. I should try how the TM works with a USB disk connected directly to router (have such router in office).
The reason not to consider the Time Capsule is as you stated - "If it's just the one machine then USB is not a bad solution". And one more router, not a cheap one, just for one computer backup... I would still miss the simplisity of previous set-up.
And will try to move back-up files around. Who knows...
Anyway some other alternatives to TM would be useful to be found
Half of 81 Gb back up on external disk is already finished. At least I will have a back up
OK, I agree, network backup is the simplest, the most transparent. It's why I use it (to a Time Capsule now, but previously to a Mac running OSX Server), but I'm backing up several Macs. However, a USB disc doesn't have to be disconnected after every backup. You could just leave it connected permanently so that TM does it's backups as it wants. Any decent backup solution should be 'set it and forget it'.
I'm not going to argue the TM vs CCC issue any more. TM has been 100% for me since it was first introduced and has allowed me to retrieve stuff (easily and elegantly) that simply would not have been possible with CCC, despite the fact that CCC is a GREAT product. But, I'll say it one more time, it is NOT the same as TM.
Adding a Time Capsule need not be considered overkill. Unless you're only using one room you need more then one WiFi BaseStation. You can never have too many for decent coverage:-) But if you're thinking of getting an Airport Extreme just to connect a USB disc, I'd say you'd be better off just getting a TC instead.
I am afraid carring around a notebook with connected USB disk is not always possible, so I will have to connect it when I would feel that I need to make a back up. And the summary of discussion is - The TM is the most convenient way to make back ups, making network backup is the most smart way to do it. TC is better than Airport Extreme (if to buy a new device) for that. Keeping any of them just for one 128Gb notebook does not make much sense. CCC is great software but not a substitution of TM. So I would need to wait until WD would arrange a new firmware or when Apple would consider third-part NAS as a suitable media for TM.
Both can happen eventually.
So far I would have to stay with TM and USB disk connected from time to time.
... I am afraid carring around a notebook with connected USB disk is not always possible, so I will have to connect it when I would feel that I need to make a back up.
FYI (pardon yet another intrusion) On a MacBook, Time Machine creates local incremental backups whenever the backup disk is not available. You can disable this feature if you want.
Just connect your Time Machine backup USB disk whenever it is convenient for you and its local backups are archived. This technique works for me.
"I should try how the TM works with a USB disk connected directly to router"
No, this would not work. Not with my router. TM expects the disks formatted as Mac OS. It cannot use other format even for USB-connected external disk. Ordinary routers would not understand such disks unless there is some specific server software like the one on WD MyBookLive, interpreting disk as a Time Machine disk.
I guess this is the reason why TM works fine with Time Capsule and a disk connected to an Airport Extreme (presumably MacOS Extended).
The recent firmware in WD is compartible with TM in MacOS X up to Lion, and is only partly compartible with Mountain Lion (seems to work, Mac OS does not complain, but it is very-very slow).
The interesting thing is, this my first backup continuously growing for I do not remember since when is pretending to speed up recently. Still 26 Gb to write from the total 113 Gb - but the estimated time is now "just" 5 days.
You seem to have the right idea about it all now. For sure, I understand your desire to use a network backup facility. My advice would be to now either chase WD to find out what they have to say about the problem (they might just be aware of it and be able to offer a complete solution) OR buy a Time Capsule OR both.
If you want to keep the costs down, it might be worth scanning eBay for a while and see if you can grab a bargain used 1TB TC. Any Airport Express you have already is still useful as a way to play music on the Mac to your music system even if it's not being used as your WiFi BaseStation.
Having said that, there is one thing still to confirm. How does the WD perform as a regular network volume with a Mountain Lion client? Does that work at full speed (so it's a problem only with TM) or does it work slowly (so it's a general ML thing). Might be worth knowing that prior to contacting WD. Also, it would determine its usability just as additional storage even if you went the TC route.
There is another complain on WD board about too slow TM backup under Mountain Lion. In those case Airport Extreme is the router. Will see. Did not find any post here and there that TM backup on WD is working. But it can also mean that others do not have my problem.
And yes, this is the way I am using Aiport Express. With iTunes Media on WD MyBookLive.
Actually just checked it (did not use with the new system yet). Not really working - first I see it for a minute or so in Airport Utility, than "was previously part of your network". Same after reset and writing network settings in again. But this cannot be related to WD MyBookLive - did not come to the stage of transfering sound through it - something else to investigate. The light on it is still green - so the device is thinking that it works...
As about the speed or regular file exchange - I did not find it different from what was before. Like now its about 400 KB/s in transfering 35Gb of data from a remote internet site to the WD through the MacBook Air connected to the network by WiFi (FireFTP). This is simultaneously with continuous backup I am concerned about. Do not have TC, so cannot compare. And may be this is a bit too heavy traffic - that is why Airport Express is dissapering.
Ok, just to skip the AirportExpress part above. Checked to have nothing to do with WD. My device is the one with 802.11n WiFi (MB321Z/A). The AirPort Utility in MacOSX 10.8.1 happened to be version 6.1(610.31). The problem seems to be (as discussed for other versions of software and hardware on various discussion boards) in IPv6 settings in Airport Express. If, differently from the default values, in Internet options "Automatically" is selected for Configure IPv6 and "Native" is chosen for IPv6 Mode - the Airport Express is steadily visible in Airport Utility, iTunes 10.7 can find it and use as speakers (with files on the WD MyBookLive NAS).
Unfortunatly it plays only one song at once through the Airport Express, than become mute, though still running a next song. Switching speakers to computer and back to the Airport Express brings sound through the Airport Express back again (for the next one song). Makes it not very useful but should be iTunes problem, not network.