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) -- Best regards, Hajime Taira <htaira@xxxxxxxxxx> RHEL Solution Architect Global Services Red Hat K.K. Ebisu Neonato 8F, 4-1-18, Ebisu, Shibuya-ku, Tokyo, Japan 150-0013 > From: Milan Broz <mbroz@xxxxxxxxxx> > Subject: Re: [PATCH] fsfreeze: suspend and resume access to an filesystem > Newsgroups: gmane.linux.utilities.util-linux-ng > Date: 2010-05-12 13:01:22 GMT (17 hours and 37 minutes ago) > > On 05/11/2010 07:25 AM, Hajime Taira wrote: > > Here is patch that add new command fsfreeze. > > 'fsfreeze' suspend and resume access to an filesystem (Linux Ext3/4, ReiserFS, JFS, XFS) > > It like xfs_freeze command for XFS filesystem. I ported one for other filesystem. > > Because util-linux-ng should have this. I think so. > > > > usage: > > # fsfreeze -f /var/ftp > > # lvcreate -s -L 10G -n ls_ftpd_snap /dev/vg_data/lv_ftpd > > # fsfreeze -u /var/ftp > > This example is wrong, device-mapper code always calls freeze_bdev() here > (which is the same like fsfreeze ioctl). > > Actually, every DM suspend ioctl calls this if there is nolockfs flag specified > (see man dmsetup suspend --nolockfs description). > > Calling xfs_freeze (or fsfreeze) before lvcreate -s is obsolete, please avoid this! > > (I guess fs is already unfrozen before the fsfreeze -u call above.) > (And there was bug in some kernel that calling twice freeze caused real freeze:-) -- 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
