X-Git-Url: https://git.proxmox.com/?p=pve-docs.git;a=blobdiff_plain;f=pvesm.adoc;h=462d9427c1965ecb2260c3a100adf03dd9541eb8;hp=8bf043e40643f08750023cf660ce5f4659c40c28;hb=ba1d96fd8f6ed0109479b65cb5f543c315d5f78c;hpb=ebc15cbca7de277cb3b49244edb9aa7a80413d40 diff --git a/pvesm.adoc b/pvesm.adoc index 8bf043e..462d942 100644 --- a/pvesm.adoc +++ b/pvesm.adoc @@ -84,21 +84,29 @@ TIP: It is possible to use LVM on top of an iSCSI storage. That way you get a 'shared' LVM storage. Thin provisioning ------------------ - -A number of storages, and the Qemu image format `qcow2`, support _thin provisioning_. -With thin provisioning activated, only the blocks that the guest system actually use will be -written to the storage. - -Say for instance you create a VM with a 32GB hard disk, and after installing the -guest system OS, the root filesystem of the VM contains 3 GB of data. -In that case only 3GB are written to the storage, even if the guest VM sees a -32GB hard drive. In this way thin provisioning allows you to create disk images -which are larger than the currently available storage blocks. You can create -large disk images for your VMs, and when the need arises, add more disks to your -storage without resizing the VMs filesystems. - -All storage types which have the 'Snapshots' feature also support thin provisioning. +~~~~~~~~~~~~~~~~~ + +A number of storages, and the Qemu image format `qcow2`, support _thin +provisioning_. With thin provisioning activated, only the blocks that +the guest system actually use will be written to the storage. + +Say for instance you create a VM with a 32GB hard disk, and after +installing the guest system OS, the root filesystem of the VM contains +3 GB of data. In that case only 3GB are written to the storage, even +if the guest VM sees a 32GB hard drive. In this way thin provisioning +allows you to create disk images which are larger than the currently +available storage blocks. You can create large disk images for your +VMs, and when the need arises, add more disks to your storage without +resizing the VMs filesystems. + +All storage types which have the 'Snapshots' feature also support thin +provisioning. + +CAUTION: If a storage runs full, all guests using volumes on that +storage receives IO error. This can cause file system inconsistencies +and may corrupt your data. So it is advisable to avoid +over-provisioning of your storage resources, or carefully observe +free space to avoid such conditions. Storage Configuration ---------------------