If these two drive combinations are used for identical day-to-day working purposes, they will give you the exact same number of backups.Ĭonsidering an example, in our situation here at MacFixIt (typing text documents, generating invoices, chatting, e-mail, Web browsing and design, and so on) we have found that it has taken more than six months to fill a Time Machine drive in a setup that has a 160GB boot drive (25GB free) and 250GB TM drive, and have about 90 backup instances on the drive (roughly 24 for the past day, 30 for the past month, and around 36 weekly backups). The same is true for a 750GB boot drive (also with just 20GB free) that is paired with a 1,000GB backup drive: both will have 270GB of extra backup space available. A 250GB boot drive with only 230GB being used (20GB free) and 500GB backup drive will give you 270GB of extra backup space on your Time Machine drive. The key in selecting a Time Machine drive is to note the difference in size between it and your working drives, and then see whether that difference will be adequate for your backup needs (keeping in mind that revolving backups will be dependent on the files you regularly edit, and not the total number of files on your disk).
As such, our recommendation is that you use a drive that is at least the size of your boot disk to avoid this potential error. Despite this, as we just mentioned you can get away with using a Time Machine drive that is only as big as the data on your disks, but remember that if the amount of data on-disk exceeds the capacity of your Time Machine drive at any point, Time Machine will not be able to back up anymore. If you are unsure about the size of the backup disk to use, the general rule of thumb is to use one that is twice as big as your boot drive and any other attached data drives combined. Granted, this defeats the purposes of Time Machine being able to go "back in time," but is an option-if nothing more than a temporary one-to get some form of backup going. However, if you are not interested in maintaining an extensive backup history and just want to be able to recover the system in the event of a crash, you can get away with having an exceptionally small drive that is just large enough to hold the data on disk and revolve through one backup instance. If you are a home-office user and just edit small documents and spreadsheets, then you can get away with a much smaller drive but still be able to have the same number of backups in your backup history as the creative professional.
If you regularly manage large media files as a creative professional, for instance, and need a huge history of backups then a large drive will be required. In answering these questions, you do not need to be specific about calculating sizes of files, but rather give yourself a ballpark figure as to what files you will be backing up.
#Time machine backup mac capacity full#
There are a couple of questions you need to ask yourself before setting up a Time Machine drive: How much of a backup history do I want, and what files do I regularly manipulate? These two questions then need to be weighed against how you would like to use Time Machine: the options being as a full system backup, or being only as a backup for specified files (by adding undesired ones to the Time Machine "exclude" list). While there is no doubt that the larger the drive the more you will be able to back up, is having a massive TM drive really necessary? One of the biggest debates out there is the proper size of the drive to use for Time Machine. Before its debut in Leopard, there were relatively few inquiries about backups, but since its inception, all kinds of worries and questions have cropped up about what the best strategy is for using Time Machine. There are a number of hotly debated topics out there about the use and setup of Time Machine.
0 kommentar(er)
