hushiey said:

I accidentally delete my customer data in computers, how do I get my deleted material? Fortunately I search on the net to file recovery for mac，It has solved my trouble!!

Hushuey

You indicated that  you deleted your customer data.  This sounds to me like you run some sort of business.  I do not run a MAC so my statements are general.

My first question to you is how much is that data worth to you, not me or any one else, but to you.

If you can put a dollar amount on the value then it is time to spend some money and get into the business of backing up your data.

There are several ways to back up data.  Some are more safe than others.  You can back up your data with either CD's or DVD's, but as time rolls along if you do not keep backing up your back ups become old and not as valuable.  You can purchase an external hard drive and back up to that, but if it sits next to your computer and the computer is stolen or a fire most likely the external hard drive is also gone or damaged.  You can also back up on line with something like Carbonite (not the only service out there).

Carbonite and an external hard drive can be setup to do the back ups automatically  which means that your back ups are up to date all the time.

No matter what choice you use any thing that places the back up off site is the safest.

The big question is not if your hard drive will fail, but when.  Or not if you will delete something important, but when and can you replace it.