If the article is correct then, by using FSEvents, it will not work the Hard disk at all, only copying new files. It does not do a full read every hour, just looks at FSEvents table, so unless you creating tons and tons of files should be very economical.
Yeah, and that's like and antivirus program which the OS takes a hit from. If the article is correct and the browser cache is one of those places TimeMachine will ignore, then it shouldn't be too bad.
Two answers: (1) perhaps you could use iDisk as one while travelling... perhaps buying more .mac space would be worth it for road warriors!
and (2) There is a wonderful drive family from Western Digital called the "My Book" family. I bought a firewire 500GB from COSTCO for around $165. They are power efficient (shut down after xxx minutes) and very reliable.
The terabyte models should be out soon. I'll get one when I move to Leapard and still use backup to .mac and the 500G drives. Can't be too safe (as I just found out Monday!!!)
I don't think dot Mac can be a Time Machine destination due to response times being too slow. Though you are warned against doing so, you can use a partition on your internal hard disk (on the same physical drive being backed up) to let Time Machine do its thing. This protects you from user error ("Oops, I overwrote a file I needed") but it will not help at all if the drive itself fails. Large external drives are the way to go with Time Machine, IMHO. I'm especially eager to see what drive makers start offering.
Second, I also have a MyBook drive and offer a few warnings about it. First, make sure you get the ones which have USB2 and Firewire interfaces if you can swing the extra $30. Firewire is slightly faster than USB2 and if you ever want to use it as an emergency boot disk, you'll have a much easier time. Another thing, is that the packaging isn't always clear how many hard drives are inside. For example, their 1TB drive is really 2x500GB drives using a software RAID that requires Windows software to run. With all that said, it's a good drive for a reasonable price (500GB = $170; 750GB = $300 )
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.
So what happens if my whole system goes down - can I retrieve the situation using Time Machine - will it replace a bootable back-up system like Super Duper?
Yes it will. However, unlike SD!'s immediate recovery by simply booting up on the cloned Volume one has to restore the system from the complete TM backup. This is done by inserting the DVD Installer, selecting a new Volume to place the system on and then selecting the TM backup to restore. The Installer will then restore your system from the chosen TM backup. After the restore completes the Volume is perfectly bootable.
The beauty of the TM restore is that you can chose from time past what you want to restore. SD! will only restore what was last cloned.
i wonder what the size of each backup file would be...
The first TM backup size will be the aggregate sum of all the data not excluded from the TM backup selection. By default TM will ***exclude*** everything except your system's boot Volume. So if your system's boot Volume is say 100 GB then the size of the first TM backup will be 100 GB. However, be aware that there's some TM management overhead so it's likely the size will be a bit larger than the 100 GB.
The size of subsequent hourly backups will amount to the data churn done in the past hour. So, if say you add to a file that was originally 20 MB another 1 MB and create new data that amounts to say 10 MB then when the next TM snapshot backup executes the size of the snapshot backup would be 21 MB + 10 MB = 31 MB (plus some TM managemenmt overhead).
TM backups are maintained as follows
1) Hourly backups for the past 24 hrs
2) Daily backups for the past month
3) Weekly backups until your backup disk fills
So in theory after 1 year you will have *approximately* (assuming 30 days in every month) 24 + 30 + 11x4 = 98 TM backups.
Does anyone have an idea of how big of a backup drive to get to use Time Machine? My internal drive is about 150GB.
Start off with a 500gig HD. If your budget is small get the least expensive one, otherwise get a combo one that provides USB 2.0, FW400 and FW800(if your Mac has FW800).
Another approach is to buy an enclosure and a retail HD to place into it. When this fills up with TM backups you can
1) Take out current HD from enclosure and insert a new one and safeguard the old. Then start a new full TM backup (this will be done automatically for you as TM will detect it's backup up to a different/new Volume)
2) Erase the current TM Volume/HD and start over again. Of course you will lose you TM backup history and if this doesn't bother you then nothing is really lost except time to srat another full TM backup.
Does this mean I am going to have to connect my external HD every hour to my macbook to make a backup? can I not make it backup just once a day or something?
Just connect the HD to your MB whenever you like. TM will notice it was attached and backup to it. If you shutdown the MB while TM backup is active you will be warned and given option to allow it to complete or you can quit and shutdown. When MB restarted after interrupting a TM backup the next TM backup will try and resume where it left off and complete the backup it started prior to you shutting down your MB.
If you look at the pictures, one of them shows the configuration pane for Time Machine, asking when to back up. The option listed is Backup at Midnight. I'm sure they will have a "Custom..." option. Don't underestimate Apple.
Here's what I wanted to know: I want to keep TWO backups. I've read that it's best to have one attached to your computer at all times as Time Machine will maintain, but another stored off-site in the event of a crash/robbery.
So, I wanted to know how/if I could accomplish this. Ideally, I would hook up one drive to Time machine, let it run for a half year, then swap out the other one, let it run for half a year and so on. But at that point, would I be confusing Time Machine, or losing data between backups or something else?
All of it is too complex. I really wanted to start doing backups as most of my valuable photos and projects have gone fully digital, but it seems not enough to me to simply have a single external drive hooked in to the computer sitting next to it. If there's a robbery or fire or something, it all goes away, including the backup.
It'd make my day to know that somehow all this logic could be easily maintained between two disks as an identical copy.
Any thoughts/assurances are welcome.
m.
This is a somewhat tough requirement to meet. What you could do is to use two HDs with one always offsite.
Use HD-1 for a week and then replace with HD-2 with HD-1 sent offsite.
After another week, replace HD-2 with HD-1 after erasing HD-1 and send HD-2 offsite.
Of course the week could be anytime frame you choose depending on how frequently you get robbed.
Remember that each time you switch in a different TM backup HD TM will want to perform a FULL backup of your data. This can be time consuming so do it just before bedtime. Also, when introducing a new HD to TM be sure to erase/re-formatt it first using Disk Utility.
What would be great is if you could boot from the leopard dvd, and run a restore which searches for a time machine backup and lets you do a complete restore back to a specified date.
Forgot to mention that with the lack of a floppy disk, Apple quickly offered iTools for data transfer and back-up when using an iMac or iBook (or any other Mac for that matter).
This is a somewhat tough requirement to meet. What you could do is to use two HDs with one always offsite.
Use HD-1 for a week and then replace with HD-2 with HD-1 sent offsite.
After another week, replace HD-2 with HD-1 after erasing HD-1 and send HD-2 offsite.
Of course the week could be anytime frame you choose depending on how frequently you get robbed.
Remember that each time you switch in a different TM backup HD TM will want to perform a FULL backup of your data. This can be time consuming so do it just before bedtime. Also, when introducing a new HD to TM be sure to erase/re-formatt it first using Disk Utility.
I don't get robbed all that often, nor do people regularly firebomb my home, I'm happy to say. I just got antsy listening to stories of people who have lost years of their lives to stuff like that. I'd be pretty sad if I lost all of my data in a freak accident. Hence the need for off-site backups.
Thanks for your suggestion though. But swapping out every week would be tedious. I wonder if I could, as someone suggested earlier, make a copy of the Time Machine drive at semi-annual intervals. There's no reason that couldn't work, is there?
Or even better... if Time Machine can use multiple disks, then I could simply hook up one drive semi-annually, and the other just leave there. Perhaps it'll somehow know the difference. Hrm. I suppose I'll just need to wait for Leopard and try all these ideas out when I have the OS running.
Beautifully written article. And well worth reading it more than once.
Perhaps many here should visit Apple's site as well, i.e., at http://www.apple.com/macosx/leopard/...memachine.html. It may help answer some of the questions and perhaps negate some of the well-meaning but ignorant and/or ill-advised responses that have cropped up here as well.
Beautifully written article. And well worth reading it more than once.
Perhaps many here should visit Apple's site as well, i.e., at http://www.apple.com/macosx/leopard/...memachine.html. It may help answer some of the questions and perhaps negate some of the well-meaning but ignorant and/or ill-advised responses that have cropped up here as well.
I don't think dot Mac can be a Time Machine destination due to response times being too slow.
Why too slow?
Doing a backup just involves sending new files up to .Mac (a background task, but yeah it requires a good broadband connection). Looking into the past, afaik, is done either
1) on a per-folder basis - retrieving individual folder information is not bandwidth intensive
or
2) a spotlight search - and Leopard allows you to send a search request to another Mac, meaning .Mac would do a search itself and merely send the results to your machine.
I think .Mac backups have HUGE potential I don't know if Apple will enable it, but it seems to be the same technology as what will be used for local server backups anyway (just slower). It'd be great if Mozy offered the same thing.
ps. Anyone know if Timemachine compresses the backups?
The easier way to explain the difference between soft and hard links, in my opinion, is like this:
A file consists of an actual file data, and directory entry, known as inode, referring to the data.
A symbolic link is a file, referring the inode of the original file, so to access the file data a system has to travel through this path:
symlink => inode => file data.
A hard link is another inode, pointing directly to the file data, instead of original file inode, as with symlinks, so to access the file data the system has to travel the following path:
inode1 => file data - to access the first hard link
inode2 => file data - to access the second.
So if you delete inode, associated with file data - in case of symlinks you loose both, your symlink, and the file (since symlink is simply a reference to the file), but in case of hard links the actual file data remains, since there's another inode (inode2) pointing to it.
Comments
If the article is correct then, by using FSEvents, it will not work the Hard disk at all, only copying new files. It does not do a full read every hour, just looks at FSEvents table, so unless you creating tons and tons of files should be very economical.
Yeah, and that's like and antivirus program which the OS takes a hit from. If the article is correct and the browser cache is one of those places TimeMachine will ignore, then it shouldn't be too bad.
Two answers: (1) perhaps you could use iDisk as one while travelling... perhaps buying more .mac space would be worth it for road warriors!
and (2) There is a wonderful drive family from Western Digital called the "My Book" family. I bought a firewire 500GB from COSTCO for around $165. They are power efficient (shut down after xxx minutes) and very reliable.
The terabyte models should be out soon. I'll get one when I move to Leapard and still use backup to .mac and the 500G drives. Can't be too safe (as I just found out Monday!!!)
I don't think dot Mac can be a Time Machine destination due to response times being too slow. Though you are warned against doing so, you can use a partition on your internal hard disk (on the same physical drive being backed up) to let Time Machine do its thing. This protects you from user error ("Oops, I overwrote a file I needed") but it will not help at all if the drive itself fails. Large external drives are the way to go with Time Machine, IMHO. I'm especially eager to see what drive makers start offering.
Second, I also have a MyBook drive and offer a few warnings about it. First, make sure you get the ones which have USB2 and Firewire interfaces if you can swing the extra $30. Firewire is slightly faster than USB2 and if you ever want to use it as an emergency boot disk, you'll have a much easier time. Another thing, is that the packaging isn't always clear how many hard drives are inside. For example, their 1TB drive is really 2x500GB drives using a software RAID that requires Windows software to run. With all that said, it's a good drive for a reasonable price (500GB = $170; 750GB = $300 )
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.
Good read though
So what happens if my whole system goes down - can I retrieve the situation using Time Machine - will it replace a bootable back-up system like Super Duper?
Yes it will. However, unlike SD!'s immediate recovery by simply booting up on the cloned Volume one has to restore the system from the complete TM backup. This is done by inserting the DVD Installer, selecting a new Volume to place the system on and then selecting the TM backup to restore. The Installer will then restore your system from the chosen TM backup. After the restore completes the Volume is perfectly bootable.
The beauty of the TM restore is that you can chose from time past what you want to restore. SD! will only restore what was last cloned.
i wonder what the size of each backup file would be...
The first TM backup size will be the aggregate sum of all the data not excluded from the TM backup selection. By default TM will ***exclude*** everything except your system's boot Volume. So if your system's boot Volume is say 100 GB then the size of the first TM backup will be 100 GB. However, be aware that there's some TM management overhead so it's likely the size will be a bit larger than the 100 GB.
The size of subsequent hourly backups will amount to the data churn done in the past hour. So, if say you add to a file that was originally 20 MB another 1 MB and create new data that amounts to say 10 MB then when the next TM snapshot backup executes the size of the snapshot backup would be 21 MB + 10 MB = 31 MB (plus some TM managemenmt overhead).
TM backups are maintained as follows
1) Hourly backups for the past 24 hrs
2) Daily backups for the past month
3) Weekly backups until your backup disk fills
So in theory after 1 year you will have *approximately* (assuming 30 days in every month) 24 + 30 + 11x4 = 98 TM backups.
Does anyone have an idea of how big of a backup drive to get to use Time Machine? My internal drive is about 150GB.
Start off with a 500gig HD. If your budget is small get the least expensive one, otherwise get a combo one that provides USB 2.0, FW400 and FW800(if your Mac has FW800).
Another approach is to buy an enclosure and a retail HD to place into it. When this fills up with TM backups you can
1) Take out current HD from enclosure and insert a new one and safeguard the old. Then start a new full TM backup (this will be done automatically for you as TM will detect it's backup up to a different/new Volume)
2) Erase the current TM Volume/HD and start over again. Of course you will lose you TM backup history and if this doesn't bother you then nothing is really lost except time to srat another full TM backup.
In the article it says this:
Does this mean I am going to have to connect my external HD every hour to my macbook to make a backup? can I not make it backup just once a day or something?
Just connect the HD to your MB whenever you like. TM will notice it was attached and backup to it. If you shutdown the MB while TM backup is active you will be warned and given option to allow it to complete or you can quit and shutdown. When MB restarted after interrupting a TM backup the next TM backup will try and resume where it left off and complete the backup it started prior to you shutting down your MB.
Here's what I wanted to know: I want to keep TWO backups. I've read that it's best to have one attached to your computer at all times as Time Machine will maintain, but another stored off-site in the event of a crash/robbery.
So, I wanted to know how/if I could accomplish this. Ideally, I would hook up one drive to Time machine, let it run for a half year, then swap out the other one, let it run for half a year and so on. But at that point, would I be confusing Time Machine, or losing data between backups or something else?
All of it is too complex. I really wanted to start doing backups as most of my valuable photos and projects have gone fully digital, but it seems not enough to me to simply have a single external drive hooked in to the computer sitting next to it. If there's a robbery or fire or something, it all goes away, including the backup.
It'd make my day to know that somehow all this logic could be easily maintained between two disks as an identical copy.
Any thoughts/assurances are welcome.
m.
This is a somewhat tough requirement to meet. What you could do is to use two HDs with one always offsite.
Use HD-1 for a week and then replace with HD-2 with HD-1 sent offsite.
After another week, replace HD-2 with HD-1 after erasing HD-1 and send HD-2 offsite.
Of course the week could be anytime frame you choose depending on how frequently you get robbed.
Remember that each time you switch in a different TM backup HD TM will want to perform a FULL backup of your data. This can be time consuming so do it just before bedtime. Also, when introducing a new HD to TM be sure to erase/re-formatt it first using Disk Utility.
What would be great is if you could boot from the leopard dvd, and run a restore which searches for a time machine backup and lets you do a complete restore back to a specified date.
This can be done with ease.
This is a somewhat tough requirement to meet. What you could do is to use two HDs with one always offsite.
Use HD-1 for a week and then replace with HD-2 with HD-1 sent offsite.
After another week, replace HD-2 with HD-1 after erasing HD-1 and send HD-2 offsite.
Of course the week could be anytime frame you choose depending on how frequently you get robbed.
Remember that each time you switch in a different TM backup HD TM will want to perform a FULL backup of your data. This can be time consuming so do it just before bedtime. Also, when introducing a new HD to TM be sure to erase/re-formatt it first using Disk Utility.
I don't get robbed all that often, nor do people regularly firebomb my home, I'm happy to say.
Thanks for your suggestion though. But swapping out every week would be tedious. I wonder if I could, as someone suggested earlier, make a copy of the Time Machine drive at semi-annual intervals. There's no reason that couldn't work, is there?
Or even better... if Time Machine can use multiple disks, then I could simply hook up one drive semi-annually, and the other just leave there. Perhaps it'll somehow know the difference. Hrm. I suppose I'll just need to wait for Leopard and try all these ideas out when I have the OS running.
Cheers!
m.
versions of a file is not reused when new versions are created. It seems like
if you heavily edited many large files, your primary drive would run out of space much
sooner than it would without Time Machine, where space from obso versions
would be reused. Is this correct? Is it a big deal?
Upon further review, it is the backup drive and not the primary drive
which cannot reuse space. Maybe the 'backup storage time limits'
is for freeing up the BU drive.
Nevermind.
The answer for this is in the article. Did you read it, or just the headline?
It's usually best to read the article BEFORE posting questions.
Mel, You are correct about reading the entire thing. When I saw "users," I did not equate it with different machines. I appreciate your post. Thanks
Perhaps many here should visit Apple's site as well, i.e., at http://www.apple.com/macosx/leopard/...memachine.html. It may help answer some of the questions and perhaps negate some of the well-meaning but ignorant and/or ill-advised responses that have cropped up here as well.
Other readings: http://www.macworld.com/2006/08/firs...emac/index.php
Beautifully written article. And well worth reading it more than once.
Perhaps many here should visit Apple's site as well, i.e., at http://www.apple.com/macosx/leopard/...memachine.html. It may help answer some of the questions and perhaps negate some of the well-meaning but ignorant and/or ill-advised responses that have cropped up here as well.
Other readings: http://www.macworld.com/2006/08/firs...emac/index.php
Unfortunately the Apple web site ref you gave is out of date and does match up with current TM features.
Also note the fine print in the Ref you gave.
"All features referenced in the Mac OS X Leopard website are subject to change"
I don't think dot Mac can be a Time Machine destination due to response times being too slow.
Why too slow?
Doing a backup just involves sending new files up to .Mac (a background task, but yeah it requires a good broadband connection). Looking into the past, afaik, is done either
1) on a per-folder basis - retrieving individual folder information is not bandwidth intensive
or
2) a spotlight search - and Leopard allows you to send a search request to another Mac, meaning .Mac would do a search itself and merely send the results to your machine.
I think .Mac backups have HUGE potential
ps. Anyone know if Timemachine compresses the backups?
A file consists of an actual file data, and directory entry, known as inode, referring to the data.
A symbolic link is a file, referring the inode of the original file, so to access the file data a system has to travel through this path:
symlink => inode => file data.
A hard link is another inode, pointing directly to the file data, instead of original file inode, as with symlinks, so to access the file data the system has to travel the following path:
inode1 => file data - to access the first hard link
inode2 => file data - to access the second.
So if you delete inode, associated with file data - in case of symlinks you loose both, your symlink, and the file (since symlink is simply a reference to the file), but in case of hard links the actual file data remains, since there's another inode (inode2) pointing to it.