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#14193 - 02/13/11 07:33 PM Opinon on time machine
kevs Offline


Registered: 12/07/09
I've avoided time machine since it was invented.
I use Super Duper to clone hardrives overnight.

One of my hardrives died in the middle of the day recently.

I did not lose data, but could have.

It seems the drain on the system and storage would be enormous with time machine. any opinions? thanks.

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#14194 - 02/13/11 07:56 PM Re: Opinon on time machine [Re: kevs]
ganbustein Offline


Registered: 08/04/09
It's hard to find anything to complain about with Time Machine. You really should be using it.

The only downside of Time Machine that I know of is that its backups are not bootable. By all means, continue using SuperDuper alongside Time Machine. Having two different kinds of backup gives you not only added protection against media failure, but adds a layer of protection against systemic errors. (By that, I mean that if someday it's discovered that one or the other method has been doing something horribly wrong all this time and no one ever noticed, or started doing something horribly wrong with a new release, you could still recover using the other.)

Do use a different physical drive for Time Machine than the one you're using with SuperDuper. Two backups to the same drive amount to only one backup.

The "drain on the system" for Time Machine is miniscule. It's extremely parsimonious of disk space, since it doesn't copy a file again unless it changes. The time requirement is also miniscule. On my machine, Time Machine needs only about 30 seconds out of every hour to do its thing. Your Mileage May Vary, of course. The initial backup will take considerably longer, because it has to copy everything. The first backup after a system upgrade is also longer than normal, because it does a deep scan to double-check that it hasn't missed anything. (It still only copies what's changed, but the deep scan adds some time.)

Time Machine never gets in your way. It does low-priority disk I/O so it won't slow you down, and it will cheerfully postpone whatever it's doing if you want to unmount the drive it's using.

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#14195 - 02/13/11 08:03 PM Re: Opinon on time machine [Re: kevs]
MicroMatTech3 Offline


Registered: 08/04/09
Both Time Machine and Super Duper are highly reliable, but in the last few months, I had Time Machine backups that appeared to be lacking recently-modified files, and a friend of mine found that his mother's Super Duper backup was being reported as larger than the size of the entire drive on which it resided. Having both of these types of backups, as suggested by gangbustein, and keeping both of them up-to-date, is the right approach.


Edited by MicroMatTech3 (02/13/11 08:03 PM)
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#14199 - 02/14/11 02:27 AM Re: Opinon on time machine [Re: kevs]
jchuzi Online


Registered: 08/04/09
Loc: New York State
My experience has been the same as Ganbustein's. I too have a Super Duper backup as well as a Time Machine backup, and on separate hard drives.
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OS 10.14.4, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365

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#14200 - 02/14/11 08:06 AM Re: Opinon on time machine [Re: kevs]
joemikeb Offline

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
I have said this before, but there is a major flaw in using Super Duper, or Carbon Copy Cloner as the only backup. Assuming you are using SD or CCC as your only backup consider this sceneario.

  • Day 1: You edit an important file and at the end of the day you backup using SD or CCC
  • Day 2: you edit the file but unknown to you there is a glitch of some sort and the file is irrepairably damaged. At the end of the day you backup using SD or CCC
  • Day 3: You attempt to open the file you have been working on for the past few days and discover it is damaged beyond repair. No problem, you simply copy the file from your SD or CCC backup. Unfortunatly that backup contains the damaged copy of the file from the Day 2 backup. You have lost all the work you have done on the file.

With Time Machine you just go back in time one more hour or one more day and recover an undamaged copy of the file having lost only an hour or so of work.

FWIW, after a logic board crash I was able to completely restore my entire system using Migration Assistant and a Time Machine backup. I will also admit I have had a TM backup set go sour for reasons I was never able to determine and I was never able to recover the backup set which forced me to start the TM backup over again from scratch.
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#14201 - 02/14/11 09:04 AM Re: Opinon on time machine [Re: jchuzi]
ryck Online


Registered: 08/04/09
Loc: Okanagan Valley
Originally Posted By: jchuzi
I too have a Super Duper backup as well as a Time Machine backup, and on separate hard drives.

Ditto. And, although I've been fortunate never to need the SD backup, I have occasionally used Time Machine for reverting to an earlier version of a file.

ryck
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Super Duper on 500GB OWC Mercury OTG Pro

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#14202 - 02/14/11 10:45 AM Re: Opinon on time machine [Re: kevs]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
I use a custom written rsync script, which backs up to another computer at my house. It's geared to be able to go over the internet if the computer is not available on the LAN, so my backups go uninterrupted as long as I have internet connectivity. I can also access my backups remotely, which I've needed to do on occasion.

The backup it makes is bootable, though it's not at the root folder of the hard drive it resides on. The hard drive has backups of multiple computers, so one large hard drive is backing up 4 machines. (something you can only get with a time capsule when using time machine) Though moving any one of the four to the root folder would turn any of them into a bootable backup.

The only downfall is the lack of versions. While I recognize the shortcoming, I have yet to run into a need for it. Every time I've needed to snag a backup it's had what I needed. But that's the one thing I admire in time machine over my solution.
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#14206 - 02/14/11 05:53 PM Re: Opinon on time machine [Re: Virtual1]
kevs Offline


Registered: 12/07/09
Thanks all, great comments.

I have all my data on one external which copies/ clones to another external the same size via SD at 4am. I also have a clone of this at the Bank- security deposit.

Been doing that for years - no time machine.

But as my hard drive fried on the spot I realized as Joe mentioned what if you were doing critical work that whole day.

Ok. questions for a time machine newbie:
How do I get started? What documentation should I read.
My new backup hard drive does have a ton of space -- over 1TB right now. My Mac HD also has one TB -- its empty except for the OS. I also have many 500GB externals I could use.

Do you make folder and back everything into it? thanks.

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#14207 - 02/14/11 08:32 PM Re: Opinon on time machine [Re: kevs]
tacit Offline


Registered: 08/03/09
Loc: Portland, Oregon, USA
There are two different kinds of backups: backups for version control, and backups that protect against hardware failure.

Time Machine is version control backup. It protects you from accidentally editing, overwriting, or deleting an important file; with Time machine, you can go back in time, so to speak, and see earlier versions of the file. Versioning backup requires a lot of space, as it spans multiple versions of a file's history.

Time machine does not protect against hard drive failure, in the sense that if you lose a hard drive you can't simply switch over to your Time Machine drive and keep going.

Super Duper, Carbon Copy Cloner, and similar programs are hardware failure backups. They create mirrors of your current hard drive, in a bootable form. If oyur hard drive suddenly ends up deep six on you, you simply boot from the copy and keep right on going, losing only any files that have changed since the last clone.

They do not, however, do version control backup. You don't get multiple snapshots of a file's revision history; you merely get an exact clone of your drive as it was at the moment you made the backup. Using CCC or SuperDuper, you can not revisit a file in previous versions to recover accidentally modified or overwritten versions.

A good backup strategy requires both. This is something I tell my clients; you need both versioning backup and hardware failure backup.
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#14209 - 02/14/11 09:19 PM Re: Opinon on time machine [Re: tacit]
MarkG Offline


Registered: 08/06/09
This may be useful. Mac 101: Time Machine
Learn how to set up Time Machine to perform backups, how to restore items (or your entire system) from a backup, how to use existing backups on a new Mac, and more.
http://support.apple.com/kb/HT1427

This should have been a reply to kev, not to tacit


Edited by MarkG (02/15/11 03:30 PM)

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#14217 - 02/15/11 08:03 AM Re: Opinon on time machine [Re: tacit]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Originally Posted By: tacit
A good backup strategy requires both. This is something I tell my clients; you need both versioning backup and hardware failure backup.


A boot drive that is a mirror, in combination with a time machine backup, is the easiest way to accomplish both. SuperDuper/CCC are effective, but not nearly as convenient as a good ol mirror, which is automatically and continuously updated, unlike CCC etc that require you to explicitly run them.
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#14223 - 02/15/11 08:42 AM Re: Opinon on time machine [Re: Virtual1]
joemikeb Offline

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Quote:
A boot drive that is a mirror, in combination with a time machine backup

As long as I am dreaming and money is no object, my preference would be a boot drive that is a RAID 5 array along with a Time Machine backup on another RAID 5 array. grin
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#14225 - 02/15/11 12:50 PM Re: Opinon on time machine [Re: MicroMatTech3]
Ira L Online


Registered: 08/13/09
Loc: California
I too live with Time Machine and a cloned copy to an external drive. However, like MicroMat observed above, Time Machine seemed to be missing a recent (2-3 days old) copy of a modified file. Never really noticed it ever before, and having another type of back up can potentially avoid this problem.
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#14244 - 02/16/11 03:06 PM Re: Opinon on time machine [Re: Ira L]
kevs Offline


Registered: 12/07/09
thanks guys, great tips.
I will get going.

I would like to perhaps either target time machine backups to an older external hardrive or -- my Mad HD has about almost the entire Terra-byte free, but is it too late to parition it?

What do you all recommend on that small issue -- where to target the backups to.

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#14248 - 02/17/11 07:15 AM Re: Opinon on time machine [Re: kevs]
joemikeb Offline

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Apple's recommendation is a drive or partition that is two to three times the size of the drive being backed up. However, with TB capacity drives that does seem to get a bit out of hand. My recommendation would be to
  1. estimate the maximum data you will ever have on your hard drive
  2. multiply that by two because it is almost a dead certainty you will underestimate by at least that much
  3. multiply that by three to get the size of the volume you should have for the Time Machine backup.

The most likely failure is not a failure in one volume or the other, it is the failure of the drive itself which immediately renders the backup a pointless exercise. Time Machine should be on a separate, preferably external, drive.

I don't partition any drive. Partitions establish fixed limits on volume capacity and you already have enough of a limit posed by the capacity of the drive. I quit partitioning drives when I upgraded to OS X 10.1. My experience with partitions had been 100% consistent: I invariably use up the space in one partition while there is still lots of empty but unavailable space available in the other partition.

Admittedly I tend to be very conservative about these things. I have a Time Machine/Time Capsule backup, a SuperDuper Clone on a industrial quality drive with a five year warranty; and I back up preferences, databases, and financial records to a MobileMe iDisk. At various times, I have used each of these to recover from a drive or computer failure.


Edited by joemikeb (02/17/11 07:21 AM)
Edit Reason: reread original post and adjusted response
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#14250 - 02/17/11 02:48 PM Re: Opinon on time machine [Re: joemikeb]
kevs Offline


Registered: 12/07/09
Joe,
I'm just doing a 150GB partition for the OS backup. The other 2.85 TB is data, and currently 1.4 TB is free.

I also back up certain things to CDR's but I think having one back up in the house and then another monthly backup hardrive in security bank deposit is pretty good backup.

Last question: Time Machine. I'm mainly doing it to be honest, just for that very rare occurrence when and if, the primary external fails, I'll have the work from that day somewhere. I dont' really need tons and tons of back ups (although that's a nice luxury) because if the overnight backup via Super Duper works -- I'm covered. I just want time machine to instantly back up what is new and not backed up by SD yet (which I schedule 1x day in middle of the night)

I'm taking about needed a backup for just a 8-10 hour period before Super Duper does its thing once a day.

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#14251 - 02/18/11 02:44 AM Re: Opinon on time machine [Re: kevs]
Pendragon Offline


Registered: 08/04/09
Loc: Georgetown, Texas, USA
Originally Posted By: kevs
I'm taking about needed a backup for just a 8-10 hour period before Super Duper does its thing once a day.


kevs,

Just curious. If you all you need is a backup for the 8-10 hour period before SD does its thing, why not merely create an additional SD schedule to that effect?
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#14256 - 02/18/11 06:09 AM Re: Opinon on time machine [Re: kevs]
artie505 Online


Registered: 08/04/09
> I'm taking about needed a backup for just a 8-10 hour period before Super Duper does its thing once a day.

> I also back up certain things to CDR's but I think having one back up in the house and then another monthly backup hardrive in security bank deposit is pretty good backup.

I dunno... On the one hand, you're concerned about an 8-10 hour period, and on the other, you're perfectly happy with having nothing more recent than a month old backup if you experience an in-house catastrophe on the last day of the month.

Sounds like in addition to whatever scheme you wind up with you also need an electronic, off-premises, daily backup..."cloud" based or otherwise.
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#14257 - 02/18/11 06:10 AM Re: Opinon on time machine [Re: Pendragon]
artie505 Online


Registered: 08/04/09
Originally Posted By: Pendragon
Originally Posted By: kevs
I'm taking about needed a backup for just a 8-10 hour period before Super Duper does its thing once a day.

kevs,

Just curious. If you all you need is a backup for the 8-10 hour period before SD does its thing, why not merely create an additional SD schedule to that effect?

Or would a mirror setup be more appropriate?


Edited by artie505 (02/18/11 06:12 AM)
Edit Reason: Add quote
_________________________
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In Memory Of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire

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#14258 - 02/18/11 07:25 AM Re: Opinon on time machine [Re: Pendragon]
joemikeb Offline

Moderator

Registered: 08/04/09
Loc: Fort Worth, Texas
Originally Posted By: keys
I just want time machine to instantly back up what is new and not backed up by SD yet (which I schedule 1x day in middle of the night)

Time Machine does not provide "instant" backups. It only backs up at hourly intervals. I am not aware of any application that provides instant backups of anything on your computer with the sole exception of synchronizing selected system data with MobileMe and that is dependent on the settings in System Preferences > MobileMe > Synch.

I'm with Artie, If all you are concerned about is that very narrow period of time and your requirement is for "instant" backups a RAID array of disks is the only option. The cheapest to implement would, of course, be RAID 1 (mirrored) array. RAID 1 can be successfully implemented in either hardware or software. If you have a fat wallet then my choice would be RAID 5 which AFIK has to be implemented in hardware but is by far the most reliable and safest. It appears you have no concern about "versioning" and if that is true, a RAID 1 or 5 array would eliminate the need for your clone backup as well.
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#14260 - 02/18/11 08:04 AM Re: Opinon on time machine [Re: joemikeb]
Virtual1 Offline


Registered: 08/04/09
Loc: Iowa
Originally Posted By: joemikeb
Time Machine does not provide "instant" backups. It only backs up at hourly intervals. I am not aware of any application that provides instant backups of anything on your computer with the sole exception of synchronizing selected system data with MobileMe and that is dependent on the settings in System Preferences > MobileMe > Synch.


Would a folder action work for that?
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#14265 - 02/18/11 12:54 PM Re: Opinon on time machine [Re: Virtual1]
kevs Offline


Registered: 12/07/09
Joe, others, Yeah, the hourly thing sounds good.

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#14266 - 02/18/11 04:43 PM Re: Opinon on time machine [Re: kevs]
ganbustein Offline


Registered: 08/04/09
Originally Posted By: kevs
I think having one back up in the house and then another monthly backup hardrive in security bank deposit is pretty good backup.

Last question: Time Machine. I'm mainly doing it to be honest, just for that very rare occurrence when and if, the primary external fails, I'll have the work from that day somewhere. I dont' really need tons and tons of back ups (although that's a nice luxury) because if the overnight backup via Super Duper works -- I'm covered.

The SuperDuper backup is important, but it won't protect you against a file being corrupted. SuperDuper will simply back up the corrupted file. Same thing for a file that gets mysteriously deleted. Once it's gone from the primary volume, the next SD backup will delete it from the secondary volume as well.

Mirroring is useful only as a defense against physical drive failure. It offers absolutely no protection against corrupted files, mysteriously deleted files, or worse, a corrupted disk catalog. At least with SuperDuper you have a few hours to notice the problem and fix it; with mirroring, damage propagates instantly to both drives.

Time Machine protects against all those things. Its only drawback is that its backups are not bootable. (And, it's only one kind of backup. You really should have two kinds of backup.)

For offsite backup, I rotate between two Time Machine backups. I actually have three TM backups: one stays at home and does hourly backups. The other two rotate, one in-house and the other off-site at any one time. For the sake of clarity, call them A, B1, and B2.

Once a week, I tell TM to back up to B1 (assuming that's the drive that happens to be onsite) and let it do one backup. Then I tell it to go back to using A for backups. I carry B1 offsite and swap it for B2. As soon as I get B2 home, I again tell TM to do one backup to B2, then switch it back to A. Next week, I reverse the roles of B1 and B2.

In effect, both B1 and B2 contain only weekly backups, each containing a backup that is at worst a little over a week old. Meanwhile, A continues to give me rapid access to recent versions, with the normal mix of hourly, daily, and weekly backups. A SuperDuper backup completes the coverage.

That sounds like a lot of backup, but I've had TM backup drives fail on me, and it's disconcerting to have all that history disappear. I haven't ever lost any data, but just like in a car, any time you use your spare you no longer have a spare. Besides, that history is useful for other things besides recovery. Sometimes you just want to know what changed and when.

(Case in point: it once was important to me to know when a particular preference got set. The modify date on the preference file wouldn't tell me, because that file got updated several times a day. But TM still had many versions of that file, and it was easy to find the first one that had the particular preference set. Losing your only TM backup makes such questions suddenly unanswerable.)

If recovery requires that I actually use my offsite backup, I've probably also lost the computer itself to fire or burglary, and the extra hour or so it takes to recover from a non-bootable backup pales beside the time it takes to replace the hardware.

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#14267 - 02/18/11 07:05 PM Re: Opinon on time machine [Re: ganbustein]
roger Offline


Registered: 08/04/09
Loc: Vermont
since we're talking about what TM does, I hope that this is an acceptable place for this query.

if I run TM, then delete files from the computer, then run TM again, the deleted files still exist on the TM drive, correct? TM just creates a second, updated backup, leaving the first intact?
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#14268 - 02/18/11 07:52 PM Re: Opinon on time machine [Re: roger]
kevs Offline


Registered: 12/07/09
nice post Gan,
I just read the Apple bit on time machine.

I assumed:

1) I could use an old 250 GB external, and then time machine would back up all files that are changed starting now.

no go? the documentation implied I need to first backup everything I own, meaning I have to buy another new 3TB external is this correct? bummer if so.

2) I would also assume I can include/exclude which folders get backed up, but I did not see this in the documentation. Not possible?

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