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Failing flash drives can be compensated for with regular backups. But you can avoid the issue entirely if it's inexpensive and easy to replace.

Hi, Leo. My 4 GB Soniq USB flash drive having performed well for a year or two with not a lot of writes, went unformatted. I'm not sure why. I thought I was treating it well. I have reformatted it, but should I trust it again? Or should I throw it away? ChkDsk says it's fine and I scanned for bad sectors but I'm just not sure. Thanks!

In this excerpt from Answercast #74, I look at the possible dangers in using a flash drive that is showing signs of failure... especially if it is not backed up.

Failing flash drives

You know, I'm really not sure either. The problem is that it depends on a lot of different factors that are kind of hard to judge from a distance.

If this is an inexpensive thumb drive, in other words, if it's not costing a lot to replace it, I wouldn't hesitate to chuck it. I would throw it away and get a new one.

Is it backed up?

On the other hand, the other approach that I would use if I wanted to continue to use this thumb drive, is I would make absolutely, positively, certain that it was always backed up. That whatever was on it could be lost, without warning, and that would be an inconvenience only - not a disaster.

I certainly wouldn't make it part of any critical processes, and I wouldn't keep any data on it that was only on it.

That would be one way to protect you from experiencing potentially fatal data loss - if this thing is really getting closer to its end of life.

Thumb drive cost and quality

That is certainly what I would do on a more expensive device. I would expect a more expensive device to last longer.

The other thing, of course, is my comments about backing it up... you know what? Even it's working, even if you've never had a problem with it, you should always be backing up the contents of your USB drives! This is simply because "if it's in only one place, it's not backed up."

It doesn't necessarily take a hardware failure to lose all that data. You could lose the thumb drive - it happens all the time.

So, by all means, keep backing up your data (or hopefully start backing up your data) and give it a try. But, like I said, you may want to just avoid the issue entirely if it's inexpensive and easy to replace.

(Transcript lightly edited for readability.)

Article C6083 - November 29, 2012 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

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November 30, 2012 8:59 AM

How do you reformat a USB Flash Drive? (novice). Does "reformat" mean the same as "erase, delete" previous data off the drive & reuse it. How do I do this? thanks

The same as you would any drive. Easiest is to right click on the drive in Windows Explorer and click on "Format...". Yes, Formatting erases the drive - quick format does it in a way that is potentially recoverable, full format does not.

Paul Schmidt
November 30, 2012 9:03 AM

Two years is a decent life span for an inexpensive flash drive. Chuck it.

Also, DO NOT EVER run full formats or CHKDSK on these drives. It reduces life. Remember, these are not "mechanical spinners". It's flash memory.

Actually I disagree: full format is called for when you want to erase the actual data on the drive so that it can't be recovered. It writes to most every sector only once. CHKDSK is mostly a read operation and will not shorten the lifespan. If it writes, it's only to fix something that needs fixing, which is typically only a few sectors. The operation to avoid is DEFRAG, which writes to the drive heavily, shortening its lifespan, and doesn't even make sense on flash media.

Joe F
November 30, 2012 2:09 PM

A full format may be called for to remove sectors that are wearing out and causing disk read/write errors. Just because a few sectors are going bad doesn't mean the drive is failing. I have one flash drive that's 6 or 7 years old - it gets a full format several times a year to "freshen it up", and it still works well. CHKDSK is a read-only operation if you don't check the boxes to fix errors - that won't add any wear to the drive. Two years is still "new", unless it gets very heavy use.

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