From: "John Austin" <ja@xxxxxxxxxx>
Newsgroups: gmane.linux.redhat.fedora.general
To: <tim@xxxxxxxxxxxxxxxxxxxxxx>; "For users of Fedora"
<fedora-list@xxxxxxxxxx>
Sent: Tuesday, October 23, 2007 9:40 AM
Subject: Re: USB drive on server?
Dup from other thread
Over 10 year life time
http://www.corsairmemory.com/_faq/FAQ_flash_drive_wear_leveling.pdf
The problem with the statistics given for Dynamic Wear Leveling is that the
flash controller must be able to know which blocks are not in use by the
filesystem. AFAIK (and this is very difficult to verify one way or the
other), consumer grade devices (at least) are only aware of FAT filesystems
and only if there is only one partition on the device. If you use ext2/3 or
have multiple partitions (both typical for Linux) the controller cannot
track blocks being freed by the filesystem and so any block ever written by
the host will looks busy to the flash controller. Therefore, writes will
only rotate through the (small) pool of extra blocks maintained by the flash
controller.
Also, AFAIK, few if any consumer-grade and, I suspect, few
professional-grade flash devices do Static Wear Leveling.
The result is that the flash drive will burn out much faster than the
statistics quoted. How much faster, I am unable to compute. It may still
be adequate for your needs. I don't know.
