Re: Using a USB stick for backups

On Nov 29, 6:38 am, "H.K. Kingston-Smith" <HK...@xxxxxxxxx> wrote:
I am using an 8 GB USB stick for my backups. The approach that I
follow consists of using rsync every other day in order to keep the
contents of the stuff in the backup in sync with the original stuff. My
question is, How long can I expect the USB stick to last?

I understand that a USB stick can be written to only so many
times, but I don't know how a write operation is to be accounted for in
this context. With my approach, the stick is written to intensively the
first time, when it is empty; however, every subsequent backup operation
will only copy the files/directories that have been changed in, or added
to, (and remove files/directories that have been removed from) the
original since the last backup operation.

Is this a sensible approach, or will it render my USB useless in
no time?

Most Flash chips have 100,000 write cycles. Some of the good chips
have 1,000,000 ; but you wouldn't be able to tell whether your flash
stick has a good chip without opening it.
As far as the storage goes, some dedicated file systems (such as
JFFS2) are excellent at how they handle flash writes. They tend to
share the burden of flash writes on all its sectors/segments (Eg: if
you re-write a single file multiple times, it gets moved to different
areas in flash [in a nutshell]). So use such a file system if
possible.
Also note that the 100,000 write cycles are a MTBF value. It may last
longer. Also every flash erase is a flash write. It writes usually
0xFF to the memory location. And every storage is a clearing of bits
from that 0xFF to what you want. Therefor I think every erase/write
is actually two writes (but don't quote me on that!).
.

Relevant Pages

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    (microsoft.public.windowsxp.hardware)
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  • Re: USB backup program
    ... Flash drives are not really very reliable for backups since the ... the life of the memory far exceeds what you state because ... A backup is not a backup unless it's backed up. ...
    (microsoft.public.windowsxp.hardware)