Differences between version 4 and predecessor to the previous major change of SambaShadowCopyHowto.
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| Newer page: | version 4 | Last edited on Thursday, April 27, 2006 3:29:24 pm | by CraigBox | Revert |
| Older page: | version 1 | Last edited on Thursday, April 27, 2006 12:10:26 pm | by CraigBox | Revert |
@@ -18,9 +18,34 @@
* [Samba] 3.0.3 or higher
* A kernel that supports [LVM] and [XFS]
-[LVM] provides a method for taking a snapshot of a volume; it is these snapshots that will be shared and provided to Windows clients as shadow copies. [XFS] supports freezing a file system, buffering writes to it until it is thawed again. To be sure of
the integrity of your
snapshot, you need to do this
. It seems like it
's possible
to do this
on [Ext3
] file systems
, but
without a similar method for freezing
, you could lose data
.
+[LVM] provides a method for taking a snapshot of a volume; it is these snapshots that will be shared and provided to Windows clients as shadow copies. [XFS] supports freezing a file system, buffering writes to it until it is thawed again. Many filesystems in
the kernel support [waiting until the filesystem is consistent before taking a
snapshot|http://www.tldp.org/HOWTO/LVM-HOWTO/snapshotintro.html] - be sure yours does before choosing something other than XFS.
+
+!Steps
+
+1. Join a Windows domain
, if
you need to. I followed [this howto|http://www.ubuntuforums.org/showthread.php?t=91510], which should be rolled into our wiki, which is a huge mess of conflicting information about joining Windows domains that really needs some Aristotle love.
+
+2. Set up a Samba share to somewhere inside your LVM volume.
+
+3. If "lsmod | grep dm" doesn
't report dm_snapshot, add "dm_snapshot"
to /etc/modules.
+
+4. If you're
on Debian or Ubuntu, check /etc/udev/udev.rules or /etc/udev/rules.d/20-names.rules for a line such as:
+
+<verbatim>
+KERNEL=="dm-
[-9
]*"
, NAME="dm/%n"
+</verbatim>
+
+udev doesn't like the creation of devices
without it having
a say, so change it to
+
+<verbatim>
+KERNEL=="dm-[-9]*", OPTIONS+="ignore_device"
+</verbatim>
+
+Source: [udev: LVM snapshots don't work|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=343671#msg20]
+
+It would also appear that with XFS
, you should ignore any websites that tell you to use xfs_freeze, as [this will hang lvcreate|http://oss.sgi.com/bugzilla/show_bug.cgi?id=400]
.
!Links
* [How to use the Shadow Copy client|http://www.petri.co.il/how_to_use_the_shadow_copy_client.htm]
+* [Some useful information about XFS & snapshots|http://c.mills.ctru.auckland.ac.nz/Samba/XfsAclWinAuth.html]
