Differences

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--- quickreference:lvm2 [2020/08/18 14:26] – rodolico
+++ quickreference:lvm2 [2024/12/07 13:36] (current) – [Too Much Information] rodolico
@@ Line 24: / Line 24: @@
 fdisk /dev/vg0/testing
 mkfs.ext4 -m 0 -L testing /dev/vg0/testing
+</code>
+===== Make it Stop =====
+Well, lvm really, really wants to make sure your stuff is there, even it the underlying volume is renamed, or even reformatted. Even after you remove the lv's, the vg's and the pv's, sometimes you still can not get it to do anything
+<code bash>
+# sometimes helpful to remove the dm's first, but not always necessary
+dmsetup ls
+dmsetup remove <name>
+# now, tell it to release the lv's. If you do not specify a path
+# releases everything
+lvchange -an <lvpath>
+vgchange -an <vgname>
 </code>
@@ Line 31: / Line 45: @@
 <code python>
+# only check RAID volumes (/dev/md0), ignore everything else
 filter=[ "a|^/dev/md|", "r/.*/" ]
+# only check /dev/sda, nothing else
+filter = [ "a|^/dev/sda$|", "r|^/dev/*|" ]
+# Finally, accept sda, sdb, any md, then ignore anything else
+filter = [ "a|^/dev/md|","a|^/dev/sda$|","a|^/dev/sdb$|", "r|^/dev/*|" ]
+</code>
+To determine which drives are actually local, you can use the **mount** command. For example:
+<code bash>
+mount | grep '^/dev'
+</code>
+will show all mounted drives which are local, ignoring nfs, tmpfs, etc...
+After making the change, rescan LVM with one of the following commands
+<code bash>
+# yes, start, not reload, not restart, start
+vgscan
+# OR
+service lvm2 start
+# OR
+lvm vgchange -aay --sysinit
 </code>
@@ Line 118: / Line 153: @@
   - If you had no problems and want the machine in the new state permanently, remove the snapshot with<code bash>lvremove /dev/vg0/snap.virt</code>
     - be sure you don't delete the wrong one, that is why I precede snapshots with "snap"
-    - Please note: running an LV with a snapshot decreases efficiency. Any writes to the original generate a write to the snapshot, so you are decreasing disk access speed greatly. Don't leave spare snapshots laying around past the time you need them,
+    - Please note: running an LV with a snapshot decreases efficiency. Many (most?) writes to the original generate a write to the snapshot, so you are decreasing disk access speed greatly. Don't leave spare snapshots laying around past the time you need them,