usb memory stick and ext3

[Vu Pham]

Lonni J Friedman wrote:
> On Mon, May 4, 2009 at 5:46 PM, Vu Pham <vu at sivell.com> wrote:
>> I have a client who uses usb memory stick for backup of their database. The
>> memory stick is formatted as ext3 and mounted then database is copied over
>> at night. Everyday the same set of files ( same names  ) are copied over.
>>
>> I notice that for an empty stick, cp copies files at a reasonable speed but
>> for a stick that already has data, cp runs extremely slowly. After a
>> reformat ( mkfs.ext3 ) the cp runs fast again.
>>
>> Any reason for this ? Anyone uses memory stick for backup ? Any
>> recommendation ?
> 
> Your realize that SS media have a woefully inadequate lifespan, and
> using them for backups is just about pointless.
> 
> Also, what's the point in putting a journaled filesystem on a USB
> stick?  IO perf is quite poor on most of them to begin with, and with
> the journaling overhead, its got to be atrocious.
> 

Thanks, Lonni. This client will eventually use some kind of external 
hard drives for their backup. For some reason, they do not have those 
drives now and want to set up the backup script so that it will also run 
when  they replace usb stick with their hard drives.

I am curious why speed changes a lot when the usb stick already has files.

Vu