Suitable size (Time Machines) backup drive?

[macstatic]

My wife's new iMac needs a backup drive, but I'm not sure which size to go for.
I'm getting her a 2.5" external Firewire 800 bus-powered drive, so an unneccesarily large drive is a waste of money in my opinion.
(if she ever does need a larger drive I can just pop in a new SATA drive mechanism in the enclosure for her).
Currently, she's used around 80 GB of her 250 GB drive. The computer's running 10.5 Leopard, so she'll be using Time Machine (being a Tiger user myself I have no experience with Time Machine, but from what I've heard it works as advertised).

She's a "general user" -not into huge audio/visual files etc., so I don't think the drive will fill up too quickly. How big a drive compared to her Mac's internal 250GB drive should she get? Will an equally sized external drive do?
I can also get a 320 GB drive, but it costs more of course.

 

[CTJoyce]

The bigger the drive, the further back you can go with your backups. Personally when I setup all my Leopard machines to backup, I created sparcebundles on my TM destination the size of the drive itself that way I wasn't backing up really old information I wouldn't need. However to each his own. My former room-mate used a 1TB drive for his 160GB Macbook because he wanted to be able to restore every change he ever made.

So its completely up to you.

Cheers
Cameron

 

[Richard1028]

I'm getting her a 2.5" external Firewire 800 bus-powered drive, so an unneccesarily large drive is a waste of money in my opinion.

Can I have a show of hands for those people with "too much" hard drive space? How about those folks that have too much space in their garage?

Yeah, I thought so.

Dude, get the larger drive. Partition off anything above 250gb for Time Machine if you want but don't get all cheap-ass on a drive that will take up the same amount of physical space and only cost a few bucks more.

 

[macstatic]

I'm not trying to be cheap-ass, but just want to make sure she actually needs it and not go for the general "get the biggest drive you can get" idea.

Does Time Machine allow for some configuration as to how many backup "rotations" it does before replacing the oldest backups with a newer one, or does it simply make as many incremental backups it can until it fills up the drive completely, then finally overwrites the oldest backup set with new data?
Also, can the user decide when to make a backup, or is he/she forced to backup at certain intervals?

The external bus-driven Firewire drive I'm getting her comes with an on/off switch: I'm hoping it's a matter of the user switching the drive on, then telling MacOSX Leopard (by clicking "Time Machine" in the dock) to back up whatever is new/changed since last time, and finally when everything's done he/she can unmount the drive and physically turn off the drive. Can it work that way?

 

[Steve J.]

I'm not trying to be cheap-ass, but just want to make sure she actually needs it and not go for the general "get the biggest drive you can get" idea.

Does Time Machine allow for some configuration as to how many backup "rotations" it does before replacing the oldest backups with a newer one, or does it simply make as many incremental backups it can until it fills up the drive completely, then finally overwrites the oldest backup set with new data?

It fills the drive and then begins to overwrite, oldest first. I think 250 GB will do you just fine. I have used Time Machine for about 1.5 years with my 320 GB iMac that isn't all the way full, and it still hasn't overwritten anything yet.

And yes, it can work that way. I'm using Time Machine on my MacBook Pro that way right now. Just make sure your eject the drive every time.

 

[DoFoT9]

for general users i would recommend 1x to 1.5x the size of their HDD, that seems to be a nice number.

 

[puckhead193]

I too need a drive for TM for my imac, is USB ok? I only have two firewire 400 ports on my imac. I need both of those, one for my scratch drive for Final cut and the other for the camera to upload the files.
Will the TM drive also back up the scratch disk that i plan to use only for FCP? (i don't want it too)

 

[DoFoT9]

I too need a drive for TM for my imac, is USB ok? I only have two firewire 400 ports on my imac. I need both of those, one for my scratch drive for Final cut and the other for the camera to upload the files.
Will the TM drive also back up the scratch disk that i plan to use only for FCP? (i don't want it too)

you can daisy chain FW devices, incase you didnt know

USB would be fine, its not as if the backup needs to happen as fast as possible

 

[macstatic]

Thanks for the replies.
So is Time Machine configurable in some way, or it is just a very basic backup system which backs everything up (like puckhead193 asked I would also like to know if you're forced to back up scratch/virtual memory files, cache files etc)?

I just tried running Time Machine on my wife's iMac, but all I could see was an on/off switch (I suppose switching it to "on" immediately starts a backup if a drive is connected?) and a button for choosing a drive. Of course I didn't have any drive connected, so there might be other options in there I couldn't see...
I hope you get an option for manually choosing when to back up, and how often you're prompted to back up (if there's no option for the latter I bet a reminder could be set up in Apple's Calendar application for say once a week).

For those who have asked about using USB drives. They should be fine for most people I'm sure, but I'm about to get a 2.5" external Firewire 800 drive for my wife for the following reasons:

1) less clutter: being 2.5" instead of the usual 3.5" means that it can draw power from the iMac itself via the Firewire cable.
USB can also do that, but you may need to use two USB ports as one often doesn't supply enough power (I have this from personal experience with a 2.5" Firewire/USB drive of mine).
A special cable with one connector at the hard drive end and two separate USB connectors at the computer end is probably supplied with the drive, or can be bought separately.
She's already used up all her USB ports, so that's not a good choice.

2) power switch: I've noticed that many (most? all?) of the cheap USB-only 2.5" external hard drives out there don't have any on/off switch. This means that the drive spins up and runs as long as the computer is turned on, and I'm sure results in a shorter life because of tear and wear.
I also assume that Time Machine will attempt to do backups whenever it "sees" an external hard drive, and if you don't want it to back up all the time (once every hour I read somewhere -not sure if that's correct) you're screwed.

Besides, she's not using her Firewire ports for anything else, so she might as well benefit from the added speed.

 

[DoFoT9]

I just tried running Time Machine on my wife's iMac, but all I could see was an on/off switch (I suppose switching it to "on" immediately starts a backup if a drive is connected?) and a button for choosing a drive. Of course I didn't have any drive connected, so there might be other options in there I couldn't see...
I hope you get an option for manually choosing when to back up, and how often you're prompted to back up (if there's no option for the latter I bet a reminder could be set up in Apple's Calendar application for say once a week).

*other information*

yes switching it to "ON" immediately starts it. the initial backup can take a few hours though.

there is an advanced sort of page so that you can un-include certain folders/files, its great but very basic.

manually backing up is easy, turn the backups off, allow time machine to be seen in the menu bar - click the TM menu bar and click "backup now" when you want to do it. this is how i do it as i dont want it always running in the background.

there is no way (no apple approved way) to do an automatic backup using the calendar and all that, however you could write applescripts that are then run via the calendar for sure.

 

[Carnivor]

I would agree with DoFoT9,

I have one of the rare 13" Alu Macbooks, 2.4, with 250gb drive, and i have a 250gb drive plugged into my airport extreme to be my time capsule, my mb drive has 131gb free, and my time machine drive has 50gb free currently as its only used for backups.

To date I can still restore right back from 31st may. So 3 months worth of backups.

 

[DoFoT9]

I would agree with DoFoT9,

I have one of the rare 13" Alu Macbooks, 2.4, with 250gb drive, and i have a 250gb drive plugged into my airport extreme to be my time capsule, my mb drive has 131gb free, and my time machine drive has 50gb free currently as its only used for backups.

To date I can still restore right back from 31st may. So 3 months worth of backups.

do you do manual backups or automatic ones? i much prefer the manual ones as i am always creating/deleting large files and im always on the move. it takes a good 5 minutes to stop backing up when i hit stop, so its rather annoying.

i can restore back to about 2007

 

[miles01110]

Can I have a show of hands for those people with "too much" hard drive space? How about those folks that have too much space in their garage?

Yeah, I thought so.

I have "too much" space in the sense that I don't use it all. It might get used at some point, but for a 250 GB drive you don't need 1 TB of backup. Just partition it at 1-1.5 times the size of your internal drive (if you include everything) and be done with it.

 

[Carnivor]

do you do manual backups or automatic ones? i much prefer the manual ones as i am always creating/deleting large files and im always on the move. it takes a good 5 minutes to stop backing up when i hit stop, so its rather annoying.

i can restore back to about 2007

I let it do it automatically, as general day to day my file sizes are not large, I have also excluded my virtual pc's from being backed up, as I do my own backups of them onto a NAS every couple of months, thats saving 15gb from being backed up. I have it set so it wont do backups when i'm on battery too.


ohh, 31st May is when i set it up! so i'm impressed its still going strong from that date.

 

[DoFoT9]

I let it do it automatically, as general day to day my file sizes are not large, I have also excluded my virtual pc's from being backed up, as I do my own backups of them onto a NAS every couple of months, thats saving 15gb from being backed up. I have it set so it wont do backups when i'm on battery too.


ohh, 31st May is when i set it up! so i'm impressed its still going strong from that date.

automatic is too often for me a annoys me too much, i could go change the backup time manually but it would still be too annoying. lol

 

[maflynn]

I'd go for the biggest you can afford.
I have the 500gig time capsule and ran into a problem with that because I did a full restore from TM and so it sensed all the files changed (why???) when it was time to do the backup. I had almost 300gig of space consumption, so in a word my 500gig drive was too small to hold multiple backups - the current history of backups and the one it was trying to do. TM then tried deleting all of the history which royally pissed me off . I had to clean it up and and start over.

If I had a terabyte drive this wouldn't be a problem.

btw, I'm in the market for a large drive now