Masatake YAMATO wrote: > Hi, > > (The disscussion can be found at > http://thread.gmane.org/gmane.linux.utilities.util-linux-ng/3181/focus=3193) > >> Hello. >> >> I understand reason when it use with device-mapper. >> I think, fsfreeze command need for filesystem on physical block device without device-mapper. >> For example, by storage controller based LUN snapshot. >> >> # fsfreeze -f /data >> # ssh root@xxxxxxxxxxx "take snapshot lun0" >> # fsfreeze -u /data >> >> * /data is mounted physical block device(/dev/sdb1) > > As Hajime wrote, taking snapshot in physical storage level is popular > situation. It seems that xfs_freeze can be used for the purpose but > the name `xfs_freeze' gives the impression that the command is only > for xfs. > > My argument can be applicable to gfs2_tool, too. "gfs2_tool freeze" > also does ``ioctl(fd, FIFREEZE, 0)''. > > > One of the solution is to add xxx_freeze for each file system implementation > which has freeze/unfreeze methods to eash util-xxx, xxx-progs or xxx-utils. > e.g. Adding ext4_freeze or ext3_freeze command to e2fsprogs package. > > However, I think this is not good idea. Linux provides file system neutral > interface already. So it is better to have file system neutral command(fsfreeze) > and the command is included in file system neutral package, util-linux-ng. I tend to agree, since there is a common interface, there is no reason to have filesystem-specific tools which all do the same thing. Note that xfs_freeze existed long before the common interface, and in fact the common ioctl number was chosen based on the xfs number, so that explains the existence of the xfs-specific tool, and why it does happen to work now on non-xfs filesystems.... -Eric -- To unsubscribe from this list: send the line "unsubscribe util-linux-ng" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
