![]() ![]() However, if you have a lot of data to check and then transfer and the external failures more frequent, then the likelihood of hitting one increases and things start to go wrong. If the external connections are reliable and the backup is quite fast the likelihood of hitting one of the nasty spots in the code is low. However, I imagine that there are places in the code where there are race conditions, or critical portions where external failure really makes a difference. The software will be designed to withstand a certain amount of external failure, especially when connecting to disks over WiFi as the Time Capsule is designed to do. my disk has 196 Gb of data, much of it in smaller document files (word docs, code files, etc.), not just a few giant movies.So guessing there is an additional factor: However, if every laptop failed as often surely Apple would have fixed it by now. maybe the WiFi aerial on a laptop is not as good as the desktop.it may go to sleep occasionally, breaking connection to the Time Capsule.I am guessing the problem I have is because I use a laptop so possible reasons: In fact lovefibre has found Time Machine flawless for her desktop machine backing up to exactly the same Time Capsule. ![]() Lesson 2: for very long processes supplement the progress indicator with some other indicator to show things are still working, in this case perhaps amount transferred in last minuteĪt this point I did the normal things, turn Time Machine On/Off, restart machine a couple of times, etc., but when it persists then you know something is deeply wrong. Of course progress indicators are never very good for very slow operations, when transferring several GB of data there may be several minutes before the bar even moves a pixel … but I was very very patient and it definitely did not move! Then (after being very very patient while to was ‘preparing’ for four hours), I saw it got stuck in step (ii) at 1.4 GB or 4.2 GB. When I got home and told Time Machine to backup to the Time Capsule here rather than my office disk (why can’t it remember that I have two backup disks?). In the days before Time Machine I always did a manual backup before travelling as I knew that was when things were most likely to go wrong, but now-a-days I have got used to relying on it and forget to check it is working OK … so if you are paranoid about your data, do peek occasionally at Time Machine to check it is still working! This last time in fact the first sign was (iii), but it doesn’t actually tell you (if you don’t look) until it has failed for ten days, by which time I was travelling. (iii) if you look in the Time Machine preferences it says the backup has failed (ii) it starts to transfer to disk, but then gets stuck part way: (i) it is still saying ‘preparing’ after leaving it overnight! However, at least half-a-dozen times over the last year, my Time Machine has got completely stuck. So, when you see ‘preparing’, just be patient! Lesson 1: make sure you include progress indicators for anything that can take a while, not just the obvious ‘slow’ things. This is when it is running over the disk working out what it needs to backup, and always seems to be the lengthiest operation, actually backing up the disk is often quite fast, and yet, for some reason there is no indication of how far through the ‘preparing’ process it has got. You can tell it is ‘preparing’ because when you open the Time Machine preferences there is the little barbers pole saying ‘preparing’ □ When you first do a backup, or when you haven’t backed up to a particular disk for ages (perhaps if you have been away on a trip), it can spend several hours ‘preparing’. Occasionally Time Machine seems to be stuck, but isn’t really. … and throughout I’ve dropped in a few lessons for anyone implementing critical system software - maybe the odd Apple engineer is reading how to tell when things are wrong This is my own story of how it goes wrong … and how to put it right. What bit of software do you really need to be reliable? If anything else goes really wrong you have the backup - but if the backup fails you really are lost.Īnd Mac OS X Time Machine, while it does have a very pretty interface, is inclined to get stuck sometimes. Unfortunately only fixing Mac OS X backup, not the Tardis □ … but, nonetheless, critical. ![]()
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