Archive for the ‘Time Machine’ Category
So I thought it would be a good idea to start using my Wireless Mighty Mouse and the nice little Wireless Keyboard again with my MacBook Pro while it is sitting on my desk connected to a nice 24″ Dell display.
Unfortunately it seems that Bluetooth is full of fail; so far my MacBook Pro has lost connection with these two devices at least once an hour. The only cure is to use the trackpad and manually turn bluetooth off and on again.
What I see in the system log file is this:
AppleFWOHCI_AsyncTransmit::waitForDMA - context not going inactive. [closeConnection] Error: L2CAP channel psm:40 wasn't closed properly - forcing it closed.
There is an 8-page thread on the Apple discussion forum. It is full of complaints about exactly this issue.
Some people say Apple is aware of the problem and claim it is related to the periodic Time Machine backups. This could be the case as Time Machine also runs every hour, which would be consistent for my case.
I also read some claims that this issue has been fixed with 10.5.6. but we’re on 10.5.7 now for a while and a lot of folks still complain.
So far there is no fix or no workaround. Except the obvious one: don’t depend on Bluetooth.
I’m so disappointed with this seriously lame case of fail. There used to be a time when Macs worked flawlessly. That great time when we could point at a Windows machine and go ‘haha’. Not anymore; Macs have just as many weird annoyances and bugs as PCs.
Please Apple. Fix this extremely lame bug that somehow slipped through your low quality quality assurance department.
Jeff Harrell has a nice blog, The Shape of Days: Pretty darned close to perfection, and he has a nice love entry about Time Machine. One of the comments explains that Time Machine is bull and that Apple should have used ZFS instead. Something I completely agree with. Jeff then replies on that saying that ZFS is too complicated.
I seriously don’t buy that ‘ZFS is too complex’ argument. In the common case where there is for example one disk with one partition in a MacBook, ZFS is not any more complex than how disks are currently partitioned with HFS.
ZFS provides a LOT of cool stuff but you certainly don’t have to use it all. Sure, when you want to implement schemes like RAID with ZFS then things become more complicated, but the same is true in the current HFS situation. And a GUI can certainly hide all ‘scary’ ZFS details there. Just as is possible now. Fire up Disk Utility if you are that Pro user.
Anyway, back to the common case where there is one ZFS partition on an iMac or MacBook. Even there the advantages are huge: you get snapshots for FREE. Snapshots will provide exactly the same functionality as Time Machine, except that they are:
- CORE FUNCTIONALITY – Snapshots are not a hack like TM currently is.
- INSTANT – There is no need to wait until a snapshot is actually made.
- DON’T REQUIRE AN INITIAL BACKUP – ZFS Snapshots don’t let you wait hours to do the first initial backup. There IS no initial backup.
- DON’T REQUIRE AN EXTERNAL DISK – ZFS Snapshots work on a single partition. You don’t need an extra disk. Time machine is useless for people working on MacBooks. ZFS could turn that around.
- TAKE NO SPACE – Snapshots take virtually no space. Until you actually start changing files that are contained in a snapshot.
- CAN BE BROWSED – Just as in Time Machine you can browse your snapshots back in time, see what files changed, open old files, etc. No magic there.
Compare that to the current implementation of Time Machine. You can’t deny the advantages of ZFS.
I actually think Apple had planned to use ZFS for OS X 10.5 in general and to base Time Machine on it too. I also think that they completely underestimated the scope of the ZFS porting effort, and that they simply missed the Leopard release window.
Let’s hope they turn it around in a later release.
Time Machine makes incremental backups of your files and puts a fancy user interface on top of it. It works well but it has one big con: it requires an external disk. How useful is that if you are say one of those 1.1 million MacBook (Pro) users (mentioned in the 2007 Q4 financial results) and you need to recover a file you just deleted while you are on the road? Well doh, not at all.
That alone makes Time Machine completely useless for many many MANY people. Interesting fact is that Apple sold about twice as many portable Macs than desktop Macs. I’m not sure who designed Time Machine at Apple, but there sure is a big disconnect here between that solution and what kind of Macs people use.
On the other hand, Time Machine would have been GREAT if Apple had build it on top of Sun’s ZFS filesystem. ZFS can do these snapshots/backups real-time on a life filesystem without requiring an extra disk. You can simply say: ok, here is my Documents folder, and I would like to make a ‘snapshot’ every hour or every time a file changes. That will result in super efficient copies of that folder, containing only the changes. With the ability to go back in time and browse through changes and restore those.
ZFS Snapshots are no replacement for real backups of course. You still want to do that too and ZFS has great support for that. Read what James Gosling (of Java fame) wrote about that on his blog.
Again ZFS magic: when he is on the road he can work on his laptop disk as usual, but then when he is back home the external USB disk is automatically sychronized to contain a hot backup of complete laptop disk. Including the above mentioned snapshots! Awesome.
Unfortunately we are stuck with a half-baked solution that only works for desktop Macs. Missed opportunity Apple. Very Lame.