Time Machine not a true backup?

Frank Caggiano wrote:

You are dangerously misreading how an incremental backup like Time Machine works. Please reread my post above and the Apple TM basics.

I'm not sure what is is that I'm misunderstanding. Please point it out to me, because I'd sure like to know!

My understanding seems to match everything you said. Time Machine keeps backups at the intervals Apple has specified, consolidating them into daily, weekly, monthly as specified in the referenced documents. At some point the drive becomes full. That's when old stuff starts getting dropped.

Right?

Network 23 wrote:

Frank Caggiano wrote:

You are dangerously misreading how an incremental backup like Time Machine works. Please reread my post above and the Apple TM basics.

I'm not sure what is is that I'm misunderstanding. Please point it out to me, because I'd sure like to know!

My understanding seems to match everything you said. Time Machine keeps backups at the intervals Apple has specified, consolidating them into daily, weekly, monthly as specified in the referenced documents. At some point the drive becomes full. That's when old stuff starts getting dropped.

Right?

I think you both are correct, but are arguing nuance details. Time Machine will make a new backup instance every time it runs, and create a duplicate of the last backup via hard links, which does not duplicate the data but only the drive's directory so the new backup "instance" points to the same data as the last. The only difference is that directory entries for changed files point to new "backed up" data for them as opposed to that from the prior backup instance. This paradigm is repeated until the drive is full, or until by Time Machine's default behavior hourly backup instances are removed.

Once the drive is full, then older instances of backups will be removed, and when the data on the drive is no longer pointed to by multiple hard links from the various backups remaining on the drive, then that data will be freed and allowed to be overwritten.

As a result, over time and with changes that fill the drive, older backups of changed files will eventually be turned over and eliminated from the drive. Their longevity on the drive depends on how you use your system and how many megabytes are regularly backed up. If you only back up a few MB per day (for whatever reason) then the TM backups will remain for a long time (especially if the TM drive is large). However, if you regularly edit a large 5-10GB movie file then regular backups of this will demand more from the TM drive and push other files off the drive, reducing backup instances that include them.

Lets say I have a 10tb drive for TM and I create a file on Monday and delete it on Thursday, how long will that file be in the backups?

Topher Kessler wrote:

This paradigm is repeated until the drive is full, or until by Time Machine's default behavior hourly backup instances are removed.

From Mac Basics: Time Machine

Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups until your backup drive is full.

Again it is only weekly's that are affected by drive size. Hourly's are gone after the day they were written and daily's only go back a month regardless of drive size.

Frank Caggiano wrote:

Lets say I have a 10tb drive for TM and I create a file on Monday and delete it on Thursday, how long will that file be in the backups?

Trick question I guess, in that the drive size is irrelevant; as I understand it the delete file will not make it into the next weekly backup. But that depends on when Time Machine makes that weekly backup.

And I guess I was wrong earlier when I mentioned monthly backups since there aren't monthly backups.

Again, its just these nuance details you're outlining. I never said anything to the opposite of these details, and there's nothing "dangerous" about how either Network 23 or I described it. Also keep in mind the backups are also revolving, so its not as if at 12:00am all of the previous day's backups are cleared out. Ultimately I think everyone here is adequately describing how it functions and has a good grasp on Time Machine's functions.

I too use Lightroom and migrating from a PC to MacBook Pro. I like the idea of my photos being set up on a separate internal drive. How do you do this? I am a new Mac user. Would appreciate your help.

I plan to use your backup method.

jtrippy wrote:

I too use Lightroom and migrating from a PC to MacBook Pro. I like the idea of my photos being set up on a separate internal drive. How do you do this? I am a new Mac user. Would appreciate your help.

It's not a big deal, really. Because Lightroom doesn't care where the photos are stored. Lightroom can catalog them on any drive. My LR references photos on like 4 different internal/external/network drives. When I import into Lightroom, I tell it where I want the photos to go (on my other disk) using the automatic date folder format I set up in the Import dialog.

If you are moving Lightroom from a PC, I haven't done it but I think the steps are:

• Download the Mac version of Lightroom, install it, plug in your serial number to make it go (the serial is cross-platform)
• Copy the LR folder/catalog from wherever it is on your PC to whereever you want it to be on your Mac (maybe in the Pictures folder? Which is analogous to My Pictures in Windows). The catalog can live on your boot drive and track photos stored on other drives like your external.
• If your photos are stored apart from your LR folder, drag your photo folder over to wherever you want it to live on your Mac (your second drive?)

After that, when you first start Lightroom, it might not see the catalog that was on the PC. Navigate to where the catalog is now on your Mac, open it, make it the default. However, that catalog might not see your photos since it last saw them in a PC drive letter location that no longer applies. What you want to do is in the Folders panel go to the top level folder that is listed under the old drive letter. Right-click on that and choose Update Folder Location and tell it where that folder is now stored on your Mac. It should automatically find and relink to all folders under it in the hierarchy.

You can boil all that down to "Move your LR files to the Mac and then relink 'em."

My question is: how does Time Machine interact with iPhoto in the sense that my library seems to be a huge file. If I add some photos to it, does it back up the whole huge file again thinking that this huge file has changed, or is Time Machine smart enough to know that its really just an unnessarily complicated Apple created directory system of photos, and just back up the recent photos added to the Library file. The first obviously will chew through a back-up drive quickly (as my iPhoto library is about 75 GBs and growing). If it just adds the recently added/edited photos, then I don't care.

It's not really a file. You can right/command click and "Show package contents".

Yes - but does Time Machine know that . . .

Actually, after I posted the above I remembered that I exclude my music and photo directories from Time Machine and back them up separately using Dropsync to duplicate the folders, because I wanted to be able to easily access these files directly in directory structures from multiple machines/operating systems etc - so its kind of a moot question for me (but it sounds like a valid question for many others who include their iPhoto libraries in their Time Machine backups).

I'm not sure if I am responding to this this thread properly or not. I am having an issue with time machine. I have an external seagate drive attached which i thought time machine was backing up to. After checking it it is not bacing up any new changes i make. i'm not sure what it is backing up. It seems to back up every hour but I'm not sure what it is backing up. Do I need to erase everything and start over? Any help would be appreciated!

The philosophy of data BACKUP (morphing and revolving, i.e. TM,...important point people dont understand in general)........... and a true ARCHIVE (cloned HD, multiple copies in safe places, secure places) ........is something EVERYONE should learn and differentiate. 😍

Very important topic in this thread.

Never consider any computer a data storage device, rather a data creation ,sending, and manipulation device. Anyone who thinks data is safe on any computer, even copied upon multiple partitions is making a mistake.

Never backup your data exclusively upon magnetic hard drives or flash storage, nor consider same since magnetic storage degrades over time even under ideal conditions.

Store important data on multiple servers on multiple continents.

Burn important data onto multiple copies of archival DVDs (Taiyo Yuden 100year rated DVD blanks) and store same in cool dark fireproof safes, multiple places.

Don’t burn data onto junk DVD’s purchased from consumer level electronics stores. These are not archival long life DVD’s nor reliable, nor trustworthy

Most importantly know that 2 copies of your data is 1, and 1 is none, and 1000 copies stored in one place or building, is also the same as none.

Always consider and expect your computer’s hard drive to completely crash anytime, at all times, and you should keep a cloned and updated hard drive handy at all times to return to immediate productivity and utterly avoid programs and parameter reinstallation and tweaking.

Nothing is quicker than taking out a dead HD and tossing in a new updated cloned HD for getting back to 100% in under 20 mins!

When your data is decentralized, it becomes both everywhere and nowhere, destructible by none.

Everyone should remember the rule 2 copies is 1, and 1 is NONE

And the computer itself never counts as one of those copies.

Ok .. Ive been using time machine for a year to backup system info and important data from a 2 TB Internal HD to a 2 TB External HD. I really only need the latest few backups ( I back up monthly ) as want to retain space on the external. Can anyone confirm the following points

1) will dat a be safe If i enter TM and delete oldest backups from the gear symbol so that i only have the last few months backup stored on HD.

2) Can TM drive also be used as a backup to another computer / to access fies occasionally or to drag - copy folders onto that system.

3)Can i store separate data on TM drive or does it need to be partitioned.

Any help with these points appreciated

I know this is not strictly related to the question..but i thought i'd add it ..although it is a bit late.

I have started using NAS4Free...as the name suggests ..it is a Free NAS server system. but it has Apple File Sharing protocol./ service built in.

It is also capable in teh AFP service of instanly making any internal HDD, shared uder AFP, fully Time machine compatibel, with he simple action of a drop down box and selecting Time Machine Compatibility.

So all you do is find any old scrap Intel based Windows PC, d/load NAS4Free burn to a CD and install on to the target computer..overwriting the Windows OS. ..stick in a big HDD or two. I used a 4TB single HDD...£100 on Dabs in the UK at the moment. So i have a 4TB NAS for the cost of 1HDD and about 2 hours work.

I also fitted a gigabit network card and connected it directly to my Mac via the second ethernet port.

Advantage with this is that I can expand by adding extra HDD's with little or no hassle.