Editing USB flash drive (section)

===File system===
{{Main|Flash file system}}

Most flash drives ship preformatted with the [[FAT32]], or [[exFAT]] [[file system]]s. The [[Omnipresence|ubiquity]] of the FAT32 file system allows the drive to be accessed on virtually any host device with USB support. Also, standard FAT [[Disk checker|maintenance utilities]] (e.g., [[ScanDisk]]) can be used to repair or retrieve [[data corruption|corrupted data]]. However, because a flash drive appears as a USB-connected [[hard drive]] to the host system, the drive can be [[Disk formatting|reformatted]] to any file system supported by the host operating system.

====Defragmenting====
Flash drives can be [[defragmentation|defragmented]]. There is a widespread opinion that defragmenting brings little advantage (as there is no mechanical head that moves from fragment to fragment), and that defragmenting shortens the life of the drive by making many unnecessary writes.<ref>[http://ask-leo.com/should_i_defragment_my_usb_flash_drive.html Should I defragment my USB Flash drive?] {{Webarchive|url=https://web.archive.org/web/20110707180424/http://ask-leo.com/should_i_defragment_my_usb_flash_drive.html |date=2011-07-07 }}. Ask-leo.com (2008-02-19). Retrieved on 2011-05-18.</ref> However, some sources claim<ref>{{cite web |url=http://www.wizcode.com/articles/comments/flash_memory_fragmentation_myths_and_facts/ |title=Flash Memory Fragmentation – Myths and Facts |website=Wizcode.com |access-date=2017-06-06 |archive-url=https://web.archive.org/web/20170614154251/http://www.wizcode.com/articles/comments/flash_memory_fragmentation_myths_and_facts/ |archive-date=2017-06-14 }}</ref> that defragmenting a flash drive can improve performance (mostly due to improved caching of the clustered data), and the additional wear on flash drives may not be significant.

====Even distribution====
Some file systems are designed to distribute usage over an entire memory device without concentrating usage on any part (e.g., for a directory) to prolong the life of simple flash memory devices. Some USB flash drives have this '[[wear leveling]]' feature built into the software controller to prolong device life, while others do not, so it is not necessarily helpful to install one of these file systems.<ref>{{cite web|url=http://www.micron.com/-/media/client/global/documents/products/technical-note/nand-flash/tn2942_nand_wear_leveling.pdf|title=TN-29-42: Wear-Leveling Techniques in NAND Flash Devices|access-date=24 January 2024|url-status=live|archive-url=https://web.archive.org/web/20231118153313/http://www.micron.com/-/media/client/global/documents/products/technical-note/nand-flash/tn2942_nand_wear_leveling.pdf|archive-date=18 November 2023}}</ref>

<!-- Note: Please don't add JFFS or YAFFS references to this article. While these two file systems, designed to minimize the inherent weaknesses of flash memory (e.g., memory wear), can be used on a flash drive, they provide no significant benefit. These filesystems are intended to assist with directly addressed flash memory (e.g. SmartMedia through a raw reader). A flash drive's memory layout is abstracted from the host system in the USB mass storage class, and the flash drive's controller chip performs tasks similar to those JFFS and YAFFS are intended for. -->

====Hard disk drive====
Sectors are 512 bytes long, for compatibility with hard disk drives, and the first sector can contain a [[master boot record]] and a [[partition table]]. Therefore, USB flash units can be partitioned just like hard disk drives.