Messages in this thread | | | Subject | Re: VFAT truncate performance | From | OGAWA Hirofumi <> | Date | Tue, 05 Sep 2006 23:59:52 +0900 |
| |
Mattias Rönnblom <hofors@lysator.liu.se> writes:
> extending files by ftruncate(2) runs very slow on VFAT file > systems. On my USB harddisk w/ VFAT, it takes 14 seconds to extend an > empty file to 1 GB. On a memory stick, it takes well over 4 minutes. > > My question is: is this problem on the conceptual level (ie there is > no way of extending files on FAT that doesn't involve many disk > operations) or is the current Linux fs driver suboptimal in this > respect?
Unfortunately FAT doesn't support sparse file, so ftruncate(2) which extend size needs to fill all clusters with zero, and write data.
This is limitation of FAT filesystem. -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |