Differences

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--- hypervisor:base:storage [2015/03/03 22:53]
admin [Virtual Block Devices (VBD)]
+++ hypervisor:base:storage [2015/03/05 12:45] (current)
admin [Delete a Storage Repository]
@@ Line 33: / Line 33: @@
 ==== Xen Storage Objects ====
 ----
-{{ :hypervisor:toolstack:xen-storage.png?direct&200 |}}
+{{ :hypervisor:toolstack:xen-storage.png?direct&200 }}
+----
+==== Virtual Disk Data Formats ====
+----
+There are three main types of mapping of physical storage to a VDI:
+  * **File-based VHD on a Filesystem**; VM images are stored as thin-provisioned VHD format files on either a local non-shared Filesystem (EXT type SR) or a shared NFS target (NFS type SR)
+  * **Logical Volume-based VHD on a LUN**; The default XenServer blockdevice-based storage inserts a Logical Volume manager on a disk, either a locally attached device (LVM type SR) or a SAN attached LUN over either Fibre Channel (LVMoHBA type SR), iSCSI (LVMoISCSI type SR) or SAS (LVMoHBA type Sr). VDIs are represented as volumes within the Volume manager and stored in VHD format to allow thin provisioning of reference nodes on snapshot and clone.
+  * **LUN per VDI**; LUNs are directly mapped to VMs as VDIs by SR types that provide an array-specific plugin (Netapp, Equallogic or StorageLink type SRs). The array storage abstraction therefore matches the VDI storage abstraction for environments that manage storage provisioning at an array level.
+----
 ===== Create a Storage Repository =====
 ----
-If you followed our [[hypervisor:base:debian|Debian Installation]] section, you should already have an LVM partition, thus a physical volume:
+The following example illustrates the SR creation on a local non-shared Filesystem (ext).
+If you follow the [[sample:base|Sample Configuration]] section of this wiki, you will have a LVM partition, thus a physical volume to use:
 <code>
-> pvdisplay
+> sudo pvdisplay
   --- Physical volume ---
-  PV Name               /dev/sda2
+  PV Name               /dev/sde5
-  VG Name               xenvg
+  VG Name               Xvg0
-  PV Size               464.83 GiB / not usable 0
+  PV Size               12.82 GiB / not usable 3.00 MiB
   Allocatable           yes
   PE Size               4.00 MiB
-  Total PE              118996
+  Total PE              3282
-  Free PE               112322
+  Free PE               5
-  Allocated PE          6674
+  Allocated PE          3277
-  PV UUID               4g97od-AZ1M-8sws-7ghY-YPaT-PsPR-mpO3iy
+  PV UUID               sJOaJc-vZzX-1d8O-2R5i-jmi5-Gkj4-S4rxdJ
 </code>
 Along with a volume group:
 <code>
-> vgdisplay
+> sudo vgdisplay
-  --- Volume group ---
-  VG Name               xenvg
+--- Volume group ---
+  VG Name               Xvg0
   System ID
   Format                lvm2
   Metadata Areas        1
-  Metadata Sequence No  22
+  Metadata Sequence No  7
   VG Access             read/write
   VG Status             resizable
   MAX LV                0
-  Cur LV                3
+  Cur LV                1
-  Open LV               3
+  Open LV               1
   Max PV                0
   Cur PV                1
   Act PV                1
-  VG Size               464.83 GiB
+  VG Size               12.82 GiB
   PE Size               4.00 MiB
-  Total PE              118996
+  Total PE              3282
-  Alloc PE / Size       6674 / 26.07 GiB
+  Alloc PE / Size       3277 / 12.80 GiB
-  Free  PE / Size       112322 / 438.76 GiB
+  Free  PE / Size       5 / 20.00 MiB
-  VG UUID               yf4fNc-5Nke-5SCd-Jqo6-ie9c-gH7r-8dCE66
+  VG UUID               Skt7yP-fl4B-IxvG-VUA4-KcJH-1Mho-2QASh8
 </code>
@@ Line 81: / Line 99: @@
 If you do not already have a device to use as repository, create a logical volume on volume group.
 <code>
-> lvcreate --size 30G -n LocalStorage xenvg
+> sudo lvcreate --size 13G -n Xsr0 Xvg0
 </code>
@@ Line 92: / Line 111: @@
 You should see your partition in a line such as:
 <code>
-Disk /dev/mapper/xenvg-LocalStorage: 32.2 GB, 32212254720 bytes
+...
+Disk /dev/mapper/Xvg0-Xsr0: 13.7 GB, 13744734208 bytes
+...
 </code>
 ==== Register the logical volume for use with XAPI ====
 <code>
-> xe sr-create type=ext name-label='Local Storage' device-config:device=/dev/mapper/xenvg-LocalStorage
+> xe sr-create type=ext name-label='X-Local-SR' device-config:device=/dev/mapper/Xvg0-Xsr0
 </code>
 This will take a while if the volume is large, it will return the SR UUID.
@@ Line 103: / Line 124: @@
 Display the storage repository:
 <code>
-> xe sr-list name-label='Local Storage'
+> xe sr-list name-label='X-Local-SR'
 </code>
@@ Line 140: / Line 161: @@
 Set the default SR
 <code>
-> xe pool-param-set uuid=<pool-uuid> default-SR=<sr-uuid>
+> xe pool-param-set uuid=<pool_uuid> default-SR=<sr_uuid>
 </code>
 ===== Delete a Storage Repository =====
@@ Line 147: / Line 168: @@
 > xe sr-list
 </code>
--> write down / take note of SR-UUID of the SR to delete
+-> Copy / write down / take note of SR-UUID of the SR to delete
 . Find the corresponding Physical Block Device (PBD):
 <code>
-> xe pbd-list sr-uuid=your-SR-uuid
+> xe pbd-list sr-uuid=<sr_uuid>
 </code>
--> write down / take note of PBD-UUID of the PBD to unplug and delete
+-> Copy / write down / take note of PBD-UUID of the PBD to unplug and delete
 . Unplug the PBD:
 <code>
-> xe pbd-unplug uuid=your-PBD-uuid
+> xe pbd-unplug uuid=<pbd_uuid>
 </code>
 . Delete PBD:
 <code>
-> xe pbd-destroy uuid=your-PBD-uuid
+> xe pbd-destroy uuid=<pbd_uuid>
 </code>
 . Delete the association of your SR and the PBD:
 <code>
-> xe sr-forget uuid=your-SR-uuid
+> xe sr-forget uuid=<sr_uuid>
 </code>
-NOTE: at this stage the logical volume will still exist in the LVM partition.
+NOTE: at this stage the SR data will still exist in the LVM partition, you could also use the //**xe sr-destroy**// command to totally wipe out the SR, loosing everything that was on it!
 ===== Using NFS =====