On Mar 7 2007 10:20, dean gaudet wrote: >>> http://gentoo-wiki.com/HOWTO_Install_on_Software_RAID#Write-intent_bitmap >> >> That information has been extremely useful. Thanks a >> lot. I fund a command to do the bitmap internal after >> the array was made so I added that. Seems like some of >> these features should be default. Maybe it's time for >> the raid folks to update what is default? > >the bitmap has performance implications... for example: >http://www.mail-archive.com/linux-raid@xxxxxxxxxxxxxxx/msg07229.html I wonder if bitmapping a raid1 volume is faster than bmp.ing raid5. The other thing is, the bitmap is supposed to be written out at intervals, not at every write, so the extra head movement for bitmap updates should be really low, and not making the tar -xjf process slower by half a minute. Is there a way to tweak the write-bitmap-to-disk interval? Perhaps something in /sys or ye olde /proc. Maybe linux-raid@ knows 8) >note that unless you tweak your init scripts you'll need to put external >bitmaps on your root partition, see this thread: Huh? That statement does not make sense. But I think you meant: when using external bitmaps, adjust the init scripts. Because internal bitmaps are good for one thing: you don't need to change anything. Jan -- - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
