Differences

This shows you the differences between two versions of the page.

--- lvm:troubleshooting_lvm [2016/07/07 09:47] – created peter
+++ lvm:troubleshooting_lvm [2019/11/30 13:59] (current) – removed peter
@@ Line 1: / Line 1: @@
-====== LVM - Troubleshooting LVM ======
-===== Errors =====
-==== Logical volume already exists in volume group ====
-You cannot create two logical volumes of the same name in the same volume group.  An error of the form:
-<code>
-Logical volume "foo" already exists in volume group "vg01"
-</code>
-indicates that you are attempting to do so.
-==== Logical volume not found ====
-An error of the form:
-<code>
-Logical volume foo not found in volume group vg01
-</code>
-could indicate that:
-  * you have specified the wrong pathname for the logical volume, or
-  * the logical volume that you intended to specify has been deleted, or
-  * one or more physical volumes were not found during discovery (in which case the volume group will also be missing).
-To establish what has happened you can request a list of logical volumes in the volume group:
-<code bash>
-lvdisplay /dev/vg01
-</code>
-then if necessary a list of volume groups known to the system:
-<code bash>
-vgdisplay
-</code>
-and a list of physical volumes known to the system:
-<code bash>
-pvdisplay
-</code>
-==== Insufficient free extents in volume group ====
-An error of the form:
-<code>
-Insufficient free extents (55211) in volume group vg01: 128000 required
-</code>
-or:
-<code>
-Insufficient free space: 128000 extents needed, but only 55211 available
-</code>
-while attempting to create or extend a logical volume indicates that the volume group does not have enough free space to satisfy your request.
-Your options are:
-  * to use a different volume group, if you have one with more space, or
-  * to delete one or more existing logical volumes to free up space within the volume group, or
-  * to add one or more physical volumes to the volume group to make it larger, or
-  * to reduce the amount of storage space that you are requesting.
-You can determine how much free space is available within a given volume group using the **vgdisplay** command:
-<code bash>
-vgdisplay /dev/vg01
-</code>
-which produces output of the form:
-<code>
---- Volume group ---
-VG Name               vg01
-System ID
-Format                lvm2
-Metadata Areas        1
-Metadata Sequence No  14
-VG Access             read/write
-VG Status             resizable
-MAX LV                0
-Cur LV                8
-Open LV               4
-Max PV                0
-Cur PV                1
-Act PV                1
-VG Size               3.73 TB
-PE Size               4.00 MB
-Total PE              976811
-Alloc PE / Size       921600 / 3.52 TB
-Free  PE / Size       55211 / 215.67 GB
-VG UUID               TkxRBk-j2Mo-Mq1a-GzTx-DKdx-2oHJ-m2o6Ua
-</code>
-The amount of free space is the second value given on the line labelled 'Free PE/Size' (215.67 gigabytes in the example above).
-==== New size not larger than existing size ====
-An error of the form:
-<code>
-New size given (1536 extents) not larger than existing size (2048 extents)
-Run `lvextend --help' for more information.
-</code>
-when running **lvextend** indicates that you requested a final size that was smaller than the current size of the volume.  This is a safety feature: shrinking a volume when you intended to expand it would be likely to cause irreparable data loss.
-If you really did mean to reduce the size of the volume then you should use **lvreduce** or **lvresize** instead.
-===== Warnings =====
-==== Rounding up size to full physical extent ====
-LVM allocates storage in multiples of the physical extent size, which is 4MB by default.  If you request a size that is not an exact multiple (for example, 255MB) then it will display a warning of the form:
-<code>
-Rounding up size to full physical extent 256.00 MiB
-</code>
-This will not usually cause any significant harm beyond using slightly more space than intended.  However, be aware that a filesystem subsequently created on this volume will (typically by default) fill the whole 256MB that has been allocated.  This could be a problem if you had a specific requirement to create a filesystem that was no larger than 255MB (perhaps because it was intended to be copied to some other medium with limited capacity).