Backing up to a thumbdrive [solved]

Walter

I spend most of my time at different computers and as a result all of my documents are stored on a thumbdrive. I like this setup a lot, I can work with my files in the lab, at home, or at a friend's. I realize how easy it is to lose/break a thumbdrive so I bought two. One stays in my comp at home and at night I usually just copy/paste from my primary thumbdrive to the secondary one, replacing all files to ensure that my secondary thumbdrive always has the latest versions of my work.

I'm a little sketch on this process though. I have a lot of research data that would be DEVASTATING if it became lost/corrupted. Is it a problem continuously overwriting the data on my secondary? I like what I'm doing because its so quick and easy.

tl;dr I copy & paste all my data from my primary thumbdrive to a backup thumbdrive almost daily. Any chance this could corrupt files or cause a loss?

Desert_Eagle25

Walter wrote: »

I spend most of my time at different computers and as a result all of my documents are stored on a thumbdrive. I like this setup a lot, I can work with my files in the lab, at home, or at a friend's. I realize how easy it is to lose/break a thumbdrive so I bought two. One stays in my comp at home and at night I usually just copy/paste from my primary thumbdrive to the secondary one, replacing all files to ensure that my secondary thumbdrive always has the latest versions of my work.

I'm a little sketch on this process though. I have a lot of research data that would be DEVASTATING if it became lost/corrupted. Is it a problem continuously overwriting the data on my secondary? I like what I'm doing because its so quick and easy.

tl;dr I copy & paste all my data from my primary thumbdrive to a backup thumbdrive almost daily. Any chance this could corrupt files or cause a loss?

I'll post this since it'll be more helpful than just me paraphrasing. Taken from ask-leo.com:

Flash memory, the type of memory used in USB thumb drives and other devices, is very, very cool. In fact I'm loading up a gigabyte SD-Ram card for my MP3 player as I type this. But there is a dark side that people don't talk about much.

Flash memory "wears out".

Flash memory chips are called "flash" because in order to write to it, the memory is loaded, and then a signal is sent to the memory circuitry that says "remember this" - kind of like the flash on a camera. (In all honesty, I don't know if modern flash memory uses this exact technique, but it remains a fairly accurate metaphor for the process.)

Once the memory has been "flashed", power can be completely removed and the memory will retain whatever was written to it.

The "problem" is that memory can be flashed only so many times. I'm finding numbers between 10,000 and 100,000 times - though as with anything, I'm sure that is increasing over time as well. Regardless, there is a limit. When that limit is approached, some portion of the memory may not properly remember what was written to it, resulting in corruption. It may only take a single bit of information to be wrong, or to "wear out", for the entire contents of a flash memory chip to be lost.

Scary, huh?

Some flash memory chips, perhaps even most, now also include circuitry to avoid "bad bits". Meaning that if portion of the flash memory finally wears out and goes bad, the chip itself can compensate and look like everything is fine. But that only lasts so long ... it doesn't prevent failure, it only postpones it.

Now, in your case, you're using USB thumbdrive in perhaps the worst possible way for longevity. Database applications in particular are notorious for writing to the disk - a lot - as tables, fields, indexes and the like are updated. Even if you don't write to your database, the files may be updated with things like "last access" information and other administrivia that still results in the USB drive being written to.
"Never run disk-intensive applications directly against files stored on the thumb drive."

With all that writing going on, suddenly 10,000 or 100,000 writes to the same location in the flash memory doesn't seem that far fetched. Remember, in the unluckiest case, it might only take one worn-out bit of information to render the entire contents unreadable.

The best use of USB thumb drives and other flash memory based devices is simply copy-to and copy-from. By that I mean copy the information to the thumbdrive to store it, copy it from the thumbdrive to a local hard disk to use it, and then copy it back to the thumb drive to store it. Never run disk-intensive applications directly against files stored on the thumb drive. If you copy to and from even 10 times a day, that's still close to three years of usage for the low end of the flash memory lifespan. (Yes, I know that's not exact. In fact, it's way more complex than that, factoring in things like the type of file system, FAT or NTFS, the efficiency of the device driver, and even the circuitry on the specific flash memory device - but it's a good order of magnitude.)

You may also note that your application speeds up when you copy your database to the hard disk for use. While reading flash memory is typically quite fast, writing is not.

And finally, if you really need external storage, a thumbdrive may simply be the wrong solution to your problem. There are plenty of external hard drives that could do the same job without the write limitations. Or perhaps a networked solution is the way to go.

Cryogen

Why not just backup your thumbdrive to your home computer's hard drive? Even if you backup to your home thumbdrive AND home hard drive, just to be safe?

Walter

Nuts, this is what I wanted to know. I'll get a cheap external and start backing up to that.

GiantRobo

You could try using drop-box if you're always around an internet connection.

Walter

Cryogen wrote: »

Why not just backup your thumbdrive to your home computer's hard drive? Even if you backup to your home thumbdrive AND home hard drive, just to be safe?

I did this for awhile. However, I can be away from my home computer for up to a month at a time which is way too long to go without backing up.