Roberto Ragusa wrote: > Ric Wheeler wrote: >> In our testing with f12, I build a 60TB ext4 file system with 1 billion >> small files. A forced fsck of ext4 finished in 2.5 hours give or take a >> bit :-) The fill was artificial and the file system was not aged, so >> real world results will probably be slower. >> >> fsck time scales mostly with the number of allocated files in my >> experience. Allocated blocks (fewer very large files) are quite quick. >> > > What kind of machine did you use? > > With 60TB a simple allocation bitmap for 4k-blocks takes almost 2GB; > and this is just to detect free space or double allocation of blocks. > Wow. > The box did have a lot of memory, it's true :) But ext4 also uses the "uninit_bg" feature: uninit_bg Create a filesystem without initializing all of the block groups. This feature also enables checksums and highest-inode-used statistics in each block- group. This feature can speed up filesystem cre- ation time noticeably (if lazy_itable_init is enabled), and can also reduce e2fsck time dramati- cally. It is only supported by the ext4 filesystem in recent Linux kernels. -Eric -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
