212 gb used on my mac - 500 gb back-up....back-up disc is full???

What kind of backup software do you use? Incremental backups obviously get bigger than the source volume due to several versions of files being kept available.

Björn

I asked about your backup software, which is Time Machine in your case. TM does incremental backups which is a good thing. This means that it will add any items to the backup that have been added or modified. So it's perfectly normal that your backup volume will be full one day. TM keeps your older backups until the backup volume is full. Then it starts to delete older backups to free some space. If you want to limit the available space for backups you would have to partition your external HD.

Björn

nellee1,

Do you have to delete everything from the backup drive because Time Machine is failing, or because you see the disk space disappearing and want to recover it?

Time Machine will eventually fill any backup drive, regardless of how large it is. However, it is designed to begin deleting older backups automatically as this occurs, to free up space for new ones.

If your backup drive is filling up quickly, there could be many reasons why it is doing so. Any large disk images that are frequently accessed and modified will cause this behavior, as the entire disk image file must be backed up after it is modified in any way. Virtual machine images are a likely candidate, here. If you have Filevault turned on, that could quickly bloat your backups. Etc.

Scott

Something does not seem right here. Your backup drive should fill up, but it usually takes months with your setup unless you are creating several gigabytes of files every day.

As an example:
My Mac HD has 160 GB in use and my TM backup is currently at 250 GB, but it reaches back for around one year!

So to clarify things, when you delete your TM backup drive and let it do its initial backup, the space used should be around (not exactly) the same as your Mac's drive. After this, only stuff that changed will get backuped hourly by TM. For me that's usually around 20 MB per hour without doing much stuff.

So it should take a long while before your TM drive gets full and Finder should report around 300 GB of free space after your inital backup. Unless, of course, you're creating very large files all the time!

Are you using any virtualization software like Parallels Desktop or VMware Fusion?

nellee,

Trust us, you want to back up everything. If you only want to backup your music, photos, and word/excel docs, then just drag those items to an external drive and be done with it.

If, however, you want something that can rescue everything for you if your internal hard drive suddenly dies, Time Machine is the answer, as is allowing it to make a complete backup.

I will again state that there could be any number of things that might bloat your backups, thus filling the external drive quickly. Virtual machine or other images that are accessed and modified frequently, large single-file databases that are accessed frequently, etc.

The intent of my original statement of these facts was to elicit some information from you concerning what might be bloating the backup in your case. Without more info, there's not much help we can provide.

It is not that unusual for an installation of 212 GBs to fill a 500 GB backup drive. In fact, an installation of 212 GBs might actually be considered "bloated" itself. Keep in mind that, should you have to format (erase) your internal drive, you'll be dealing with the recovery of 212 GBs worth of data. And the question is not whether or not you will have to do this at some point, but rather when. It would benefit you to remove some of that data to dedicated external drives or optical media, thereby reducing the amount of data from your internal that must be backed up on a regular basis.

Scott

Hi. I'd have to agree with Scott that TM is best used if you let it back up your entire system.

But as to what's causing the unusual size of your backups, there are some things that can cause this, and there are ways to minimize it.

The usual suspects are File Vault; any virtualization software; any app such as Entourage that keeps all it's data in one big file or database.

There's also a handy app (that ought to be part of TM) that you can use to see just what's taking up so much space. It's called TimeTracker, and is available from www.charlessoft.com. If you find things listed there that you don't understand, post their names and locations, and somebody here can probably help identify them.

I may have missed that answer somewhere, but do you use FileVault?

Yes, it's a security feature that encrypts your home folder into a disk image which could be the cause for your rapidly filling TM volume. Go to System Preferences/Security/FileVault and see if you have it activated.