Hi, As I know, checkpointing is a fundamental technique of the NILFS. It is possible to imagine checkpointing as an act of final placing of file system blocks on disk storage. Another filesystems also writing on disk but, usually, without possibility to keep history of file system operations and manage by history. Checkpoint in NILFS is natural possibility to prevent from file system inconsistency and failure by means of Copy-On-Write policy. Of course, checkpoints keep duplicates of metadata and data information but obsolete checkpoints can be deleted by nilfs_cleanerd. So, from my point of view, your approach is trying to overcome the main goal of the NILFS. What about reliability in your approach? Everything can occur during operations under tmpfs partition (for example, sudden power off). I think that it doesn't exist ideal file system that can be best in all possible workloads. So, if you have some use-case or workload in that NILFS is not so good, maybe it will be better to use another file system? With the best regards, Vyacheslav Dubeyko. On Jul 14, 2012, at 8:31 PM, Ivan Shmakov wrote: > It was mentioned recently [1] that NILFS doesn’t handle frequent > file “creation-removal” cycles well, and these are typical to, > in particular, # apt-get install (upgrade) operation. > > I’m currently using NILFS for “root” filesystems of a couple of > chrooted environments I use to test new software, which implies > that Debian packages are installed and upgraded quite often. > > As a work-around, I’ve made a copy of the filesystem on tmpfs, > and run # apt-get from there, like: > > # chroot /tmp/debian.UvYusUaj apt-get upgrade > > Then, I propagate the changes back to the original NILFS root > with rsync(1), like: > > # rsync -x -a -v -rlOtH \ > -b --suffix=.~$(date +%s)~ --backup-dir=.rsync-backup \ > --exclude=/.rsync-backup/ --exclude=/.nilfs \ > --delete \ > -- /tmp/debian.UvYusUaj/ /srv/chroot/2012-07-06-unsafe/ > > This obviously results in much less checkpoints, too, and thus, > AIUI, less overall stress to the filesystem. > > (Sometimes, I’d also chcp(8) the latest of the newly-made > checpoints into a snapshot.) > > [1] http://permalink.gmane.org/gmane.comp.file-systems.nilfs.user/2397 > > -- > FSF associate member #7257 http://sf-day.org/ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
