Software suggestions for testing a hard drive.

[amiga78]

I got a hard drive from work 2 weeks ago, for rendering some large files. The hard drive worked fine for ~1TB and started writing increasingly larger chunks of zeros short there after. The files seamed fine but the content was mostly black. Very irritating when doing work with a deadline.

Question. What is a good way to test a hard drive if reliability is a bit important, and I don't want to wait for a week testing a 2 or 4TB drive.

When formatting a hard drive, the slow way, it will write zeros to the entire surface, but it will not test reading back anything as far as I understand, so i guess that would not help much would it?

I have previously been using this: http://alternativeto.net/software/quick-disk-test/ for testing smaller USB drives, but it seems to be discontinued anyway.

Mostly working on Mac but am open for testing Win programs if they seem any good. Preferably nothing to expensive 😉

 

[Paperdoc]

If you really do NOT want to preserve anything already on that disk, the best tool I can suggest is a utility to Zero-Fill the disk. I don't use a Mac so I can't recommend any particular one, but there are many as freeware.

Be aware that a Zero-Fill will DESTROY all data on the HDD.

The reason for doing this follows. Every HDD these days has a small set of self-diagnostic tools built into its mobo. A Zero Fill operation will write all zeros to EVERY Sector of the HDD. As that is done, the HDD's internal tools will read back every such write and assess the reliability of the signals. If good, it just keeps going. If signals are weak or if actual errors in the written data appear, it will designate that Sector as faulty. Then it does 3 things. First, it re-reads several times and tries to get good data from that Sector (in this case, that part does not matter). Then it marks that Sector as Faulty in its own on-disk records so it will never be used again. Finally, it selects a new Known-Good Sector from its stock of spares and uses that to replace the faulty one, and writes to that replacement the data it recovered (if it was able). You see, at the time when the HDD is first manufactured and its Low-Level Format done, the HDD has more Sectors than needed for its rated capacity. All Sectors are tested at that time, any faulty ones set aside, and all-good ones assigned to be used for rated capacity. The remaining good ones are noted in an on-disk location for use as this stock of "spares". Throughout the life of the unit, every read and write operation is supposed to trigger this little self-diagnostic action, resulting in a HDD that seems to "repair" itself constantly by replacing poor Sectors with good ones. (But sometimes this seems to miss a faulty Sector.) This action happens within the HDD and it not apparent to the OS, so your OS never knows about it. By running a Zero Fill operation, you force the HDD to do its self-diagnostic on EVERY Sector and replace all the faulty one so that the OS will see it are perfect with no "Bad Sectors". But in addition, the HDD checks just how often this substitution is done. Eventually it will send out a warning through the SMART system when a limit is exceeded. The warning means two things. One is that the stock of known-good spares has been reduced so that sometime soon there won't be any good spares and the self-repair process cannot work. Secondly, if that many repairs have been needed so far, it is likely that it will continue at an increasing rate, so failure is likely in the near future. So your response to this warning should be to replace the HDD and copy all the data it contains off it NOW while it is still working.

Once you have done the Zero Fill you should look for the SMART data by using a disk diagnostic utility. One item there will be the count of Sectors that have been replaced. If that is too high, that is your warning that the HDD is near failure. If it's OK, you can have confidence in the HDD, and know that only Good Sectors are available for use on it because any faulty ones have been hidden away and cannot be accessed by any OS.

 

[amiga78]

If you really do NOT want to preserve anything already on that disk, the best tool I can suggest is a utility to Zero-Fill the disk. I don't use a Mac so I can't recommend any particular one, but there are many as freeware.

Yes but can You recommend any specific apps for this? Win or Mac...
And I always thought that a zero-fill was part of regular (slow) formatting, are You sure that the HD reads the zeros after writing?

 

[Paperdoc]

I can't recommend any software for a Mac because I don't use them. But if you're working on a PC, a popular free utility package is DBAN, and it includes a Zero Fill tool. Some HDD makers also provide free utility packages for download from their websites for use only with units made by them. For example, WD has Data Lifeguard, and Seagate has Seatools. Each of these can be downloaded in either of two forms. The "for DOS" versions are .iso files that need to be burned to a new blank CD to create a bootable disk you can boot and run from with NO functioning HDD in the machine. They also have "for Windows" versions that can be run under a Windows OS.

CAUTION!! These Zero Fill tools destroy all data on a HDD, of course. So be VERY careful NOT to apply them to a disk with data you need! Best practice is to DIS-connect temporarily any and all drives in a machine that you do NOT want to work on.

A Full Format operation in Windows will fill with zeroes. BUT it only works on the Sectors that are a part of a functioning Partition. A Zero Fill utility, on the other hand, will do that job for EVERY Sector of the HDD, ensuring that it is completely wiped out.

The self-diagnostic step of reading back what was just written to a Sector (and possibly replacing faulty Sectors) is part of the internal process of the HDD unit itself. It is NOT dependent on the OS, so it does get done. Doing the Zero Fill on the drive ensures that this is done for EVERY Sector on it.