How Effective Is Formatting?

[Mike Soda]

I'm considering re-purposing the old HDD in my HP Pavilion 513x as a backup drive in my current PC which only currently has a single 1TB Hitachi HDS721010CLA SCSI. Although the last load of scans I ran on that PC +5 years ago said it was clean. That's not to say it's HDD was never infected with malware in the even more distant past, all was removed of course but still I worry. You're probably wondering why I want to re-use such an ancient drive but that's not entirely accurate. Although the above stays true to the HDD in question, it's not the original & has enough space. So in terms of actual use it's only got about ~3 years of mileage which in my opinion would be perfect for the year or less that I need a backup drive for. Once the below questions check out I'll begin the long process of booting that dinosaur of a PC & getting it's specs.

 

1: If I reformatted that HDD from the HP Pavilion 513x, is there any remote chance of malware residue causing me problems backing up my OS & personal files to it?

 

2: I really don't have the money to buy a small HDD for backup but if #1 is true, what sub 500GB HDD's for well under $50.00 would y'all recommend?

 

3: If #1 isn't true, then what software would you recommend for the formatting & mirroring/backing up process?

[Mike Soda]

*Update: Just thought I'd make notice that it is storming & my UPS has limited power. So no rush answering the above questions/concerns since it'll be a good day before I can even attempt to turn on that older PC.

[mariushm]

On a classical hard drive, a full format will overwrite each sector on the disk surface and verify that the sector was fully erased. It's 99% safe to say that you won't have any viruses on that hard drive. For most users, formatting is enough.

Information after a format can in some cases still be recovered and for that reason some recommend specialized software applications that perform safe erase (they write random data several times over the whole surface to make sure you can't recover anything). Others especially in military or medical areas, don't risk it and just destroy the hard drive completely. 

In some really extreme cases (really really rare, maybe a handful of viruses in the world and very rare), a virus can hide itself in the firmware of the hard drive (the software running on the microprocessor on the hard drive's printed circuit board), or hide most of it's "body" in areas of the hard disk platters that are normally not used to store data, to be recovered at a later time (think very tiny virus that can't infect other computers, infecting you from internet or somewhere and recovering what it needs to attack other computers from hard drive instead of downloading that from Internet) . These like I said are extremely rare, and basically you shouldn't worry about something like this happening to you.

 

[BrightCandle]

A quick format having removed all reference to the files will mean its basically impossible for the OS to load any old virus stored in the contents of the drive. A full format would wipe most sectors to 0 and remove the ability for any software or commercial entity to recover any contents that was on it. A quick format is sufficient.

[Mike Soda]

4 hours ago, mariushm said:

On a classical hard drive, a full format will overwrite each sector on the disk surface and verify that the sector was fully erased. It's 99% safe to say that you won't have any viruses on that hard drive. For most users, formatting is enough.

Information after a format can in some cases still be recovered and for that reason some recommend specialized software applications that perform safe erase (they write random data several times over the whole surface to make sure you can't recover anything). Others especially in military or medical areas, don't risk it and just destroy the hard drive completely. 

In some really extreme cases (really really rare, maybe a handful of viruses in the world and very rare), a virus can hide itself in the firmware of the hard drive (the software running on the microprocessor on the hard drive's printed circuit board), or hide most of it's "body" in areas of the hard disk platters that are normally not used to store data, to be recovered at a later time (think very tiny virus that can't infect other computers, infecting you from internet or somewhere and recovering what it needs to attack other computers from hard drive instead of downloading that from Internet) . These like I said are extremely rare, and basically you shouldn't worry about something like this happening to you.

 

 

57 minutes ago, BrightCandle said:

A quick format having removed all reference to the files will mean its basically impossible for the OS to load any old virus stored in the contents of the drive. A full format would wipe most sectors to 0 and remove the ability for any software or commercial entity to recover any contents that was on it. A quick format is sufficient.

Thank you both so much, unfortunately I just now discovered that the HDD I planned on re-using is only 40GB which isn't enough so oh well.