For me this depends on what type of HDD it is and if the damaged sectors are multiplying.

My 20MB MFM HDD in my 286 had more then a megabyte worth of bad sectors when I got the system but not a single sector has given up since although the system is in use almost daily, I see no reason to replace the HDD.

I purchased a SpinRite license a few years ago and it is a perfect tool for old hard drives. A level 4 scan reads and re-writes the contents of each sector 4 times. In the cases where a sector has not gone bad yet but its magnetic signal has weakened, this tends to refresh the sector and prevent a reallocation from occurring. So I run SpinRite on every drive I care about once a year or so and none have ever shown bad sectors in the time I've done this. If a drive already has bad sectors, it relocates the data to spare sectors and tells the HDD controller about it so the remapping is kept track of. It's a great tool for keeping drives healthy well beyond their years. There are limitations to SR, but they are mostly with larger (>1TB) drives.

The things wich matter - do new bad sectors appear and how fast. If you notice new bad sectors every several days or even with every next check - it's better to backup HDD and throw it to trash.

Easy, a drive with a single bad sector can't be trusted to store files. Retro drives aren't mission critical, so just keeping things backed up elsewhere is enough of a precaution.

I dont like bad sectors, i try to replace the drive if i get any bad sectors.

candle_86 wrote:

I dont like bad sectors, i try to replace the drive if i get any bad sectors.

Depending where they are, I might still use the drive. For example, I have one that has a row of bad sectors at the end of the drive (based on SpinRite's sector map). I short-stroked the drive by partitioning and using only the area before it, and use SR to keep the rest of the sectors healthy. But yes, having a good backup is important, regardless. DOS is easy, though. I just connect the DOS drive to a Windows PC and copy the partitions there, where they in turn fall under the Macrium Reflect backup policy.

In 9 out of 10 drives I've had, mechanical failure seems to precede bad sectors to the point that the drive completely stops working before any bad sectors even appear, or, they appear once the mechanical failure is well under way to the point I'm replacing the drive anyway. That isn't to say it works this way for everyone else. To be honest, I wouldn't trust a drive with bad sectors and I'd probably give it up if I could get a new one, but my 286's full height Maxtor has a few bad sectors on it and has done nothing bad since I put it in, so with any luck it isn't getting any worse. At least, not at a rate that will inconvenience me any time soon, plus I once again expect it will fail mechanically first, it doesn't spin up as fast as it used to and read/write operations are much more "clunky" sounding than they used to be... It is nearly 30 years old, so its best years are likely long since behind it.

Thinking more on the subject, I think I'd react differently depending on the machine. If, say, my K5 developed a few bad sectors, I'd probably ignore it until something serious went wrong (Like it not booting) because it doesn't do anything important. On the other hand, if my P60 developed even a single bad sector I think I'd be backing everything up and changing the disk because I actually use that system for "important" things. That drive might then be re-purposed for a less important machine like the K5 though, if I thought it had a bit of time left.

I've got a Tandy 1000RL with a functional hard drive heading my way soon, so I'm genuinely curious what sort of condition it'll be in. I plan on replacing it with an XT-IDE device anyway, but it's neat that these things are still chugging along after 25+ years.

However, if a modern hard drive exhibited bad sectors I'd immediately move to replace it, but what real choice will I have with some ancient hardware?

I really wish Lo Tech could develop a MFM/RLL/XT to CF adapter...

Only on rare occasion have I had a drive go bad, mechanically. I've come into possession of so many hard drives with "bad sectors" on them, over the years and they always come back after a Low-Level Format in as much as the bad sectors are gone and don't seem to come back.

I keep an eye on the SMART report in HD Tune Pro, and they always turn out fine. I'm not saying they will always be fine, but slow far slow good.

Anything IDE or SCSI with bad sectors gets tossed. Anything ESDI , MFM, RLL with a few documented bad sectors is ok as long as nothing goes bad after I get it.

While I don't keep anything critical on my old machines I also don't like spending the time reloading a working machine because the HD went dead. Having said that I have not had to toss that many drives over the last 15 years of collecting. Very rarely an old drive (like say a SCSI in an old mac II or Mac SE) just quits working entirely. I have had to recap the drive controller board on an IBM PS/2 Model 30 286 to get it working again (and it had bad sectors when I got it).

The old interface drives usually had a bad sector map printed, which you re-applied on low level format.
IDE drives conceal them by remapping - and while some drives / utilities support additional remapping, it can be a very temporary Band-Aid.

On the other hand, if it survives a test without throwing more bad sectors, then the cause may be transient.

I use modern storage devices with my retro computers: What's bad sectors? 🤣

PhilsComputerLab wrote:

I use modern storage devices with my retro computers: What's bad sectors? 🤣

Yeah i noticed. In some of your videos you use a 2TB hard drive but only use a fraction of it's space. I guess this is for testing purposes only?

Well, i've been busy testing a great amount of hard drives and discovered a few that were either like new, some were on their way out and even small number of them already dead 🙁

For future monitoring i decided to make a few labels and either stamp them, or the computer in question:

The labels:

A not so good hard drive:

An even worse hard drive (that explains why the laptop was always giving weird windows errors):

A HP Vectra with a few bad sectors, although it still works like champ:

I pretend with these labels to monitor the number of bad sectors in the future and see if they increase.
Hell, even my main computer at work which has a 500GB hard drive has already 3 bad sectors (35078 hours and counting).

PhilsComputerLab wrote:

I use modern storage devices with my retro computers: What's bad sectors? 🤣

If you mean SSDs, they're not inmune to bad sectors.

TELVM wrote:

PhilsComputerLab wrote:

I use modern storage devices with my retro computers: What's bad sectors? 🤣

If you mean SSDs, they're not inmune to bad sectors.

After almost 7 years as my OS drive this is how the SMART status of my Intel X25-M G2 80GB disk looks. It might not be a fast disk by todays standards but it is very reliable.

Edit

It seems it has 3 damaged sectors or at least an unormalized reallocated sector count value of 3, still not bad for all this time.

Only 26176 power on hours count! 😁

It seems the OS install date was 2009-07-14, it's likely the same day I got the disk.

It was when an i7 920 on an Asus P6T Deluxe was my main system, I did not reinstall the OS when upgrading to the EVGA SR-2.

My Windows 7 install probably is the Windows 7 release candidate as it's installed before retail went live.
I do own W7 Ultimate retail though (and every other version by now).

/Edit

For DOS machines, as long as I have a good backup of the HDD (I don't often make changes to my DOS machine once it is set up), I'd run the HDD til it bit the dust, then just restore my backup to the next HDD. But Windows OSes change a bit more dynamically, so at the first sign of trouble, I'd attempt a repair with SpinRite, or just replace the drive before it gets to an unrecoverable state.

i use HDD Regenerator 1.71. That Dos app saved my ass many times

i tend to reeplace the HDD if i see more than 100, also depends where. I reeplace the HDD if give me bad sectors from the start.

just curious, what do you guys use to test old hard drives?

Half-Saint wrote:

just curious, what do you guys use to test old hard drives?

SpinRite here for thorough tests. In a pinch, scandisk. Something simple like Speccy to check SMART parameters.