Time Machine backup behavior erratic, now not working at all

Question

[ Using Lion 10.7.2 on a Macbook Pro 15" with 2.53GHz Intel Core 2 Duo processor, 4GB RAM. ]
The Macbook is connected to our home LAN, and I have been using (since September) a Synology NAS drive on the network which is set up as the Time Machine backup drive. Most of the time for these past months it has been fine; some issues initially with connectivity which were finally solved by using a static IP address for the NAS.
Recently it did the first strange thing. It had been performing incremental backups as normal, when a message came up saying the backup was unreliable and it needed to carry out a complete new backup. Anyway - no drama - I took it up and plugged it into the router to speed up the transfer (around 200GB on the drive). It worked fine and thereafter it went back to doing incremental backups normally.
Yesterday morning I noticed it was apparently running and running without progress, clicking on the bar icon revealed that TM was "Preparing Backup"; this state continued for several hours. So I stopped the backup, restarted the machine, and then last night at 22h00 I restarted it - by 08h00 this morning, ten hours later, it was still "Preparing Backup", so clearly something is wrong.
The NAS drive is accessible, ie.
- The 'Time Machine Backups' icon for the drive has appeared on the desktop
' The 'Diskstation (Time Machine)' is available in Finder under 'shared'
So this seems to be something to with Lion and/or with Time Machine.
Considering the infrastructure environment has been stable for months, the IP address of the drive is static, there appear to be no network connectivity problems... I am at a loss as to why now this irritating behaviour and, more to the point, at the moment I cannot make the Mac backup. I would be happy to do another full backup but, really, should not be necessary since this only happened (due to the recently problem) a few weeks back - and anyway what's the point of automated incremental backup if (a) it doesn't work reliably and (b) every 2-3 weeks you have to manually perform a full backup anyway??!!
Thanks in advance
Alastair

Answer 1

Alastair Mac wrote:
thanks. unfortunately a locally attached drive isn't a option that will work well for me (too long to explain, but it just won't - personal logistics rather than technology issues).
Are you sure about that? I have a Time Capsule (2nd hand) but I've switched back to a locally attached disk with Lion. Lion's new mobile backups provide some measure of backups when not connected to the backup drive. It protects against accidental deletions, but not hardware failure. Plus, the new bootable recovery partition in Time Machine and encryption tip the balance back in favor of the local drive - for me at least.
1. does it make sense to you that, until yesterday, it was working fine and then quite suddenly it stopped working?
I will say that it isn't surprising. There are some changes in Lion that affect networked Time Machine devices. The early versions of Lion got pretty annoying. 10.7.2 seemed to be better. I had to erase my Time Machine drive a couple of times and do new backups when it decided it needed to keep rebuilding the Spotlight index. Unless you connect with Ethernet, the reindexing will never finish. In your case, I would expect a 3rd party, flaky open-source product to perform even worse.
2. in my specific situation (going around and around "preparing backup" without any progress even in 24hrs of preparing, what can i do to restart the backup process? even if it means doing a clean backup i.e. junking the old one, i would live with it as at present (touch wood) my hard drive is OK and i have no historical version recovery issues.
With Time Machine, the only quick and easy way to reset things is to erase the Time Machine volume.
3. did apple / synology reach a point in previous releases of OSX and DSM which was stable and DID work, despite the need to use Netatalk? in other words, if i soldier on patiently, is it likely this will eventually get solved? or will this be a perennial problem? in the end, if twice a year i have to intervene, it doesn't really matter PROVIDED the backup itself is intact should the HD finally die. of course, if i have to intervene every couple of days, i may as well do it all manually.
I can't really answer that. I used Netatalk briefly several years ago and it scrambled my files. It has certainly improved somewhat, but obviously isn't stable. The part that really annoys me is that the change that Apple introduced in Lion wasn't really new. Apple introduced a more secure version of the AFP protocol 9 years ago. In Lion, all they did was make that more secure protocol the default and disabled the older protocols. There are a number of hacks that have been posted (sometimes by me) about how to set a flag in Lion so that it will continue to use the older protocol.
Synology seems to have better Mac support that some NAS vendors. Still, there was no reason they had to wait so long to update their software. Developers have had access to Lion for almost a whole year.
I would expect that companies would be always trying to improve their products, but the evidence doesn't support that assumption. I don't like Netatalk's shady open source extortion practices, but then no one else has stepped up to fund a stable open-source implementation of AppleTalk. People tend to blame Apple but they published the new specifications a decade ago and no one bothered to read them. Why should they care?
Personally, I think backups are too important to rely on such flaky software. I really like Time Machine but it is pretty complicated. Apple is able to make it functional over a network, but just barely. If you are using a 3rd party NAS, my suggestion would be to use NFS instead and backup with Carbon Copy Cloner or SuperDuper!. Even if you want to continue to try using Time Machine, a Carbon Copy Cloner backup would be a good thing to have too.