Hello again, Just curious, is anyone seeing similar things with big VM images or other DBs? I forgot to mention that my vdi file is 88GB. It's surprising that it took longer to count the fragments than to actually defragment the file. Or that it took 3 defrag runs to get down to 11K extents from 104K. Are others seeing similar things? Marc On Thu, Jun 04, 2015 at 05:42:45PM +0900, Marc MERLIN wrote: > Hi Chris, > > After our quick chat, I gave it a shot on 3.19.6, and things are better > than last time I tried. > > legolas:/var/local/nobck/VirtualBox VMs# lsattr Win7/ > ---------------C Win7/Logs > ---------------C Win7/Snapshots > ---------------C Win7/Win7.vdi > ---------------C Win7/Win7.png > ---------------C Win7/autotune1.png > ---------------C Win7/new_autotune2.png > ---------------C Win7/Win7.vbox-prev > ---------------C Win7/Win7.vbox > > But I have snapshots of that subvolume, so obviously that gets > in the way of disabling COW. > > I had a look, and I have 100K fragments. That took 10mn to figure out: > > legolas:/var/local/nobck/VirtualBox VMs/Win7# filefrag Win7.vdi > Win7.vdi: 104306 extents found > > This first filefrag run took about 10mn to count all the fragments on my > SSD. That feels a bit slow, but maybe the userland tool is doing things > in suboptimal ways. > > Defrag actually worked (mostly) and wasn't too slow. It used to take hours > not to finish, and now it worked in 3mn: > legolas:/var/local/nobck/VirtualBox VMs/Win7# time btrfs fi defrag Win7.vdi > real 3m43.807s > user 0m0.000s > sys 0m44.044s > > This is defintely better than before. > Note that it's not fully defragged, but close enough. Each subsequent > run, filefrag is faster, and defrag is still faster than filefrag: > > legolas:/var/local/nobck/VirtualBox VMs/Win7# time filefrag Win7.vdi > Win7.vdi: 11428 extents found > real 2m42.090s > user 0m0.000s > sys 2m37.308s > > legolas:/var/local/nobck/VirtualBox VMs/Win7# time btrfs fi defrag Win7.vdi > real 0m7.483s > user 0m0.000s > sys 0m2.672s > > legolas:/var/local/nobck/VirtualBox VMs/Win7# time filefrag Win7.vdi > Win7.vdi: 11132 extents found > real 0m22.525s > user 0m0.000s > sys 0m22.264s > > It's a bit unexpected that I still have 10k fragments after 2 defrag > runs, but it's better than 100k :) > > Marc > -- > "A mouse is a device used to point at the xterm you want to type in" - A.S.R. > Microsoft is to operating systems .... > .... what McDonalds is to gourmet cooking > Home page: http://marc.merlins.org/ | PGP 1024R/763BE901 > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
