Road to Mac OS X Leopard: Time Machine

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  • Reply 81 of 139
    One of the rumour sites spoke about Apple's portable user logins. In essence, a remote device holds all of the user data including passwords & some (or all) user files. The idea was that you could go up to any Mac's user-login screen, plug in an external device (eg iPod) and your username would appear in the user-login screen. You login with your own password, apps, files... everything.



    Is it possible that a TIme Machine backup (onto a 160GB iPod, for instance) could ALSO be a portable home directory for any mac you plug into?
  • Reply 82 of 139
    Quote:
    Originally Posted by GregAlexander View Post


    One of the rumour sites spoke about Apple's portable user logins. In essence, a remote device holds all of the user data including passwords & some (or all) user files. The idea was that you could go up to any Mac's user-login screen, plug in an external device (eg iPod) and your username would appear in the user-login screen. You login with your own password, apps, files... everything.



    Is it possible that a TIme Machine backup (onto a 160GB iPod, for instance) could ALSO be a portable home directory for any mac you plug into?



    The iPod is not a supported TM backup device.
  • Reply 83 of 139
    suhailsuhail Posts: 192member
    Quote:
    Originally Posted by deep View Post


    Seriously, you guys rock for posting these in-depth articles. Kudos to you and your team



    I totally agree, excellent work Ai
  • Reply 84 of 139
    suhailsuhail Posts: 192member
    Quote:
    Originally Posted by Booga View Post


    This is a good background article, but it misses the point of Time Machine, I think. Backing up files is old news, and I'm sure Time Machine does it as well as anyone. The real magic of Time Machine, though, is information retrieval. It's something that Shadow Copy and rsync can't hope to do.



    In a traditional file backup solution, if you discover one missing record in your Address Book, you'd have to go get all your incremental backups, restore each file in turn, look for the record, and if you find it export it manually, then restore the current version and import it.



    With Time Machine, you just search back through time using the same search field you do normally. It will go back in time and find the first instance of the search criteria and allow you to restore just that record to the present. THAT is revolutionary. The rest is just another implementation of an old concept.



    These points were not missed, they were on the last page of the article.
  • Reply 85 of 139
    Quote:
    Originally Posted by khyros View Post


    ...snip...

    b) This is about the hourly/weekly backups.



    For example:



    Oct 12 7pm : newly created File A is backed up to TM

    Oct 12 8pm : file A was previously (7.30pm) delted so it doesn't appear on this hourly backup.

    Oct 13 12am: daily backup from Oct 12 is backed up to TM. It doesn't contain file A, but file A is backed up in hourly 7pm from oct 12.



    Now... a few days later, it comes the time to delete hourly backups... how does TM manage to keep file A in the TM pool for me to recover at a later time?



    TM will keep your File A around for a period of 24 hr and then it will be expunged as you correctly surmised. However, if the Trash has not been emptied File A will remain in the Trash until such time you empty the Trash. Once the Trash is emptied then File A will be gone.
  • Reply 86 of 139
    Superb article. Full marks for explaining Time Machine in an understandable way and with reasonable depth.



    Has anyone else noticed how well this fits with the Airport base station's ability to host a network drive. I'd think it a bit of a pain to constantly have an external hard drive plugged into my laptop (or to be plugging and unplugging all the time), but if everyone in the house was automatically backed up as soon as they arrived home, well, that's just so brilliant, and convenient!



    Mendosi
  • Reply 87 of 139
    Quote:
    Originally Posted by bxs6408 View Post


    TM will keep your File A around for a period of 24 hr and then it will be expunged as you correctly surmised. However, if the Trash has not been emptied File A will remain in the Trash until such time you empty the Trash. Once the Trash is emptied then File A will be gone.



    well if that's the case then TM has a serious flaw!!

    for daily backups: a file won't be kept in TM if it's created and delted on the same day.

    for monthly backups: a file won't be kept in TM if it's created and deleted on the same month.



    This sounds all so weird and wrong to me ...
  • Reply 88 of 139
    Quote:
    Originally Posted by khyros View Post


    This sounds all so weird and wrong to me ...



    Any regular backup... if it was done at midnight daily... would miss a file that was created at 7am, and then deleted at 7pm.



    However, TM will backup every hour... so you're safe there (unless created and deleted within the same hour). For a file that is months old, it's not going to keep every version of the same file... and I guess if you only have a file on your computer for 15 days, then you'll lose the file.



    THis would happen on regular backup schedules too.





    Anyway, overall this won't bother me as I keep files on my computer for 6 months at least... but perhaps this will bother people...
  • Reply 89 of 139
    If the Mac which has created the Time Machine Backup fails and comes to the End Of It's Life.

    Can you attach another Mac to that external hard drive and access those backup files without doing a system restore?

    Paul
  • Reply 90 of 139
    Barry,



    Will TM do the same for your "BootCamp" Volume? No one seems to know. If so, I'm sold!



    Bob





    Quote:
    Originally Posted by bxs6408 View Post


    TM will restore a complete system backup and it will be bootable afterwards. Pop in the DVD Installer disc, select the Volume you wish to restore to, select the complete TM backup you want to restore from, wait for it to complete the restore operation and then you will have a bootable system once again. Works just fine, easy to do and without any real fuss.



  • Reply 91 of 139
    Quote:
    Originally Posted by Quarky View Post


    If the Mac which has created the Time Machine Backup fails and comes to the End Of It's Life.

    Can you attach another Mac to that external hard drive and access those backup files without doing a system restore?

    Paul



    I'm assuming you're asking if the old TM backup Volume can be used to restore its associated System and User data to your new Mac. I'm also assuming the old Mac's TM was backing up all the System and /User data. TM allows the user to exclude backing up System data. If user does so then obviously a complete System cannot be restored. When using the DVD Installer to restore from a previous TM backup only 'complete' TM backups will be listed for selection.



    If the new Mac is same hardware (i.e., Old Mac was Intel-based and new Mac was Intel-based and suspect that the hardware is compatible in all respects or new Mac is simply your old Mac that has been repaired) there should not be a problem in doing this.



    If the old Mac had a boot Volume name of say Quarky-HD then this Volume name will propagate to your new Mac.



    Note that the TM Backup Volume you are restoring your System from must be a device that the DVD Installer can recognise. Typically this would be an external device such as USB HD or FW HD or AirDisk (and maybe network device - not sure about this though as it would depend on the network being fully functional during the early part of the DVD Installer process). Any device requiring 3rd party driver code will not be seen by the DVD Installer as it will not have the driver code to use.
  • Reply 92 of 139
    Quote:
    Originally Posted by bobandris View Post


    Barry,



    Will TM do the same for your "BootCamp" Volume? No one seems to know. If so, I'm sold!



    Bob



    Interesting question. I don't know for sure - sorry.



    However, even though TM, by default, excludes all volumes except the boot volume it is possible to change this. Thus if the Boot Camp Volume were named let say 'BC-HD' then user would remove BC-HD from the TM's exclusion list and allow TM to backup BC-HD.



    At some later point if BC-HD failed, got corrupted suddenly or whatever, then the TM browser can be used to restore the BC-HD volume to a past time point the user felt BC-HD was in good shape such as 1 day ago or 4 days ago or 1 month ago.
  • Reply 93 of 139
    physguyphysguy Posts: 920member
    Quote:
    Originally Posted by bxs6408 View Post


    Interesting question. I don't know for sure - sorry.



    However, even though TM, by default, excludes all volumes except the boot volume it is possible to change this. Thus if the Boot Camp Volume were named let say 'BC-HD' then user would remove BC-HD from the TM's exclusion list and allow TM to backup BC-HD.



    At some later point if BC-HD failed, got corrupted suddenly or whatever, then the TM browser can be used to restore the BC-HD volume to a past time point the user felt BC-HD was in good shape such as 1 day ago or 4 days ago or 1 month ago.



    First, I don't really know the answer but if TM uses FSEvents to track changes, I doubt that is will do the Boot Camp volume as it is read-only (I think this is still the case in Leopard) to OS X and therefore will show no FSEvents.
  • Reply 94 of 139
    Quote:
    Originally Posted by bxs6408 View Post


    TM will keep your File A around for a period of 24 hr and then it will be expunged as you correctly surmised. However, if the Trash has not been emptied File A will remain in the Trash until such time you empty the Trash. Once the Trash is emptied then File A will be gone.



    No way. If you create a new file, i.e., A and it is back up with Time Machine one hour and deleted within the next hour, the original back up of A is still there on the back up drive.



    Best you read this article again and visit Apple's web site. A lot of questions continue to be raised and they are well answered on the two sites. Postulating on what Time Machine can or can not do by some of the meanderings here, only confuse the understanding.
  • Reply 95 of 139
    areseearesee Posts: 776member
    Quote:
    Originally Posted by AppleInsider View Post


    The flip side is that some users get a backup system set in place that appears to be working, and are lulled into a false sense of security, unaware that it isn't. The faults might lie with unreliable back backup media, procedures not being carried out correctly, or the system not capturing new data it was not originally designed to protect.



    Good article. I especially appreciated the discussion about 'Hard Links' and 'Soft Links'. But the article didn't address problem #2, validating the backup. Does TM know that the data got transfered to the backup ok? Or that the file in the backup is still good and hasn't gotten corrupted over time? -- For example, I rip a CD or import a photo. While I may be accessing the primary file periodically I will probably not be changing it. So after a year or so I will have a lot of hard links pointing to a single backup file. But how will I know that the data in the backup file is any good or not?
  • Reply 96 of 139
    Quote:
    Originally Posted by GregAlexander View Post


    Any regular backup... if it was done at midnight daily... would miss a file that was created at 7am, and then deleted at 7pm.



    However, TM will backup every hour... so you're safe there (unless created and deleted within the same hour). For a file that is months old, it's not going to keep every version of the same file... and I guess if you only have a file on your computer for 15 days, then you'll lose the file.



    THis would happen on regular backup schedules too.



    This is so wrong! Unless of course your are doing a full back up and tossing the previous one each time. Certainly not what Time Machine is intended to do.



    As the article so simply describes, connect your computer (A) to a new external drive (B) and Time Machine will open and ask you if you want to use (B) as a Time Machined backup drive. Saying yes, and Time Machine copies everything from (A) to (B).



    From then on, every hour (A) is connected to (B), Time Machine (and forget how it does so for the moment), with affect every file on (A) that is different from the last back up to (B).



    Time Machine does not delete a file on (B) because it was removed from (A) since the last back up, or for that matter, any other previous ones, or any in the future. It just remains on (B) to let you restore it, or any or every 'hourly' snapshot later when you may want.



    If we think about it, Time Machine has not only made backing up idiot proof, it is giving us an opportunity to keep our machines lean and mean, i.e., only having the most important active files on board. And for those who like to experiment, an added comfort of going back in time to at a click of a mouse.
  • Reply 97 of 139
    Quote:
    Originally Posted by Abster2core View Post


    No way. If you create a new file, i.e., A and it is back up with Time Machine one hour and deleted within the next hour, the original back up of A is still there on the back up drive.



    Best you read this article again and visit Apple's web site. A lot of questions continue to be raised and they are well answered on the two sites. Postulating on what Time Machine can or can not do by some of the meanderings here, only confuse the understanding.





    apple hasn't clarified my doubts that's why I ask here for those of you who have actually tried TM.



    hourly backups are only kept for a period of time (a week?) then those are tosed and only weekly and then monthly backups are kept; all according to what i've read here and in the guide.



    if file A is in the hourly backup but not on the mac's drive when the weekly/monthly backup is done, ultimately file A will be lost when hourly backups are deleted by Time Machine.



    or so it seems and that's why I think it's weird...
  • Reply 98 of 139
    physguyphysguy Posts: 920member
    Quote:
    Originally Posted by khyros View Post


    apple hasn't clarified my doubts that's why I ask here for those of you who have actually tried TM.



    hourly backups are only kept for a period of time (a week?) then those are tosed and only weekly and then monthly backups are kept; all according to what i've read here and in the guide.



    if file A is in the hourly backup but not on the mac's drive when the weekly/monthly backup is done, ultimately file A will be lost when hourly backups are deleted by Time Machine.



    or so it seems and that's why I think it's weird...



    Why do you want a backup of a file you threw away on purpose? Conversely why are you throwing away a file you want to keep? ( in your example)
  • Reply 99 of 139
    Quote:
    Originally Posted by Abster2core View Post


    This is so wrong! Unless of course your are doing a full back up and tossing the previous one each time.



    My initial impression was the same as yours - everything backed up, all older versions of the same file, etc etc.



    However, it doesn't actually say that. As far as I've read (here and at Apple), Time Machine actually takes snap shots of your system. If the file is not on the system during that snapshot, then it won't be in the backup. Further, when the older daily backups are 'thrown out' leaving only monthly backups - if the file wasn't there during the monthly snapshot, it won't be in the backup.



    Quote:
    Originally Posted by khyros View Post


    I think it's weird...



    It's the same as any other backup. If you backup daily at 6pm you'll have a copy of whatever was there at 6pm that day. If at the end of the month you only keep one backup, you'll only have what was on that backup. Any version changes during the month are not kept (unless your file records version changes itself). Any file that was created one day and deleted the next is not in the end of month backups.



    This is ALMOST never a problem though. How often do you need a file that you created and kept less than a month? Time Machine, afaik, is not an archive solution - it's a backup solution. If you want to get things off your hard disk when they're no longer active, you'd probably want a different program.

    (edit)

    ie: If you want to do a project, finish it, and then say "okay, I can delete that... it'll be in the backups"... then that's not what these backups are for. Time machine is different to taped backups because it makes it easy to get to the old info... but it's not supposed to be used as you're thinking. Think about archiving instead.
  • Reply 100 of 139
    Does anyone have an idea of how TM would interact with Parallels? It would seem problematic, because whenever Parallels is active, you'd be making small changes to the virtual drive for your Parallels machine, meaning that a multi-GB file would need to be copied over every hour. Is this how it works?
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