Googling I found that would be useful to add instructions on how to detach and re-attach a local storage ( separate disk ) to XenServer. It is necessary to use command line interface (CLI).
We can see Storage Repository using xe sr-list:
# xe sr-list
uuid ( RO) : 37239476-c08f-ad02-c776-77830c73d6c6
name-label ( RW): Local storage
name-description ( RW):
host ( RO): xs-602
type ( RO): lvm
content-type ( RO): user
uuid ( RO) : 38faf3c9-f7ab-a8b6-4fb9-80a4745c2b05
name-label ( RW): sr xenserver 5
name-description ( RW):
host ( RO): xs-602
type ( RO): lvm
content-type ( RO): user
uuid ( RO) : c425f5fb-1e60-685c-0a1c-6cc11a0087b7
name-label ( RW): DVD drives
name-description ( RW): Physical DVD drives
host ( RO): xs-602
type ( RO): udev
content-type ( RO): iso
...
...
Add a Local Storage Repository ( SR )
To add a Local Storage Repository check the SR available in the host using pv display. We can see the default XenServer Local SR and if there are others disks attached others SR. Disks maybe temporary attached and with full XenServer installation,too.
# pvdisplay
--- Physical volume ---
PV Name /dev/sda3
VG Name VG_XenStorage-37239476-c08f-ad02-c776-77830c73d6c6
PV Size 290.09 GB / not usable 7.81 MB
Allocatable yes
PE Size (KByte) 4096
Total PE 74260
Free PE 17919
Allocated PE 56341
PV UUID fOijAs-Dyb0-IUvH-5UzC-ivnj-Jx4u-c51TzT
--- Physical volume ---
PV Name /dev/sdb3
VG Name VG_XenStorage-4f9d6505-0f10-5e08-9629-4a4813ec57a7
PV Size 1.81 TB / not usable 8.06 MB
Allocatable yes
PE Size (KByte) 4096
Total PE 474881
Free PE 414464
Allocated PE 60417
PV UUID JI2nT4-Aaj3-XIns-jpPy-YSJ6-isSV-9wkTsm
We can see two LVM volumes. The first, in sda disk, is the main XenServer local SR, the second is 1.8 TB LVM volume in sdb disk. To attach SR is necessary :
- recognize the Storage Repository in XenServer
- create the SR physical block device (PBD)
- then plug the PBD to XenServer
Let the Storage Repository recognizable using xe sr-introduce
[root@xs61 ~]# xe sr-introduce uuid=4f9d6505-0f10-5e08-9629-4a4813ec57a7 type=lvm name-label="sr-l-T18" content-type=user
4f9d6505-0f10-5e08-9629-4a4813ec57a7
Now we can see SR in XenCenter and it will be marked as Detached.
We have to create the PBD ( physical block device) using xe pdb-create command. To use the command, you need the host uuid and device name of the partition.
xe host-list
uuid ( RO) : 6acdd0f6-cad4-4d46-b852-16c645e6c8b5
name-label ( RW): xs-602
name-description ( RW): Default install of XenServer
To know the /dev/sdb3 devicename we can use ls -l /dev/disk/by-id
[root@xs61 ~]# ls -l /dev/disk/by-id total 0 lrwxrwxrwx 1 root root 9 Jan 13 13:57 scsi-SATA_WDC_WD20EARX-00_WD-WCAZAJ973153 -> ../../sdb lrwxrwxrwx 1 root root 10 Jan 13 13:57 scsi-SATA_WDC_WD20EARX-00_WD-WCAZAJ973153-part1 -> ../../sdb1 lrwxrwxrwx 1 root root 10 Jan 13 13:57 scsi-SATA_WDC_WD20EARX-00_WD-WCAZAJ973153-part2 -> ../../sdb2 lrwxrwxrwx 1 root root 10 Jan 13 13:57 scsi-SATA_WDC_WD20EARX-00_WD-WCAZAJ973153-part3 -> ../../sdb3 lrwxrwxrwx 1 root root 10 Jan 13 13:57 scsi-SATA_WDC_WD20EARX-00_WD-WCAZAJ973153-part4 -> ../../sdb4 lrwxrwxrwx 1 root root 9 Jan 13 13:57 scsi-SATA_WDC_WD3201ABYS-_WD-WCARW3003070 -> ../../sda lrwxrwxrwx 1 root root 10 Jan 13 13:57 scsi-SATA_WDC_WD3201ABYS-_WD-WCARW3003070-part1 -> ../../sda1 lrwxrwxrwx 1 root root 10 Jan 13 13:57 scsi-SATA_WDC_WD3201ABYS-_WD-WCARW3003070-part2 -> ../../sda2 lrwxrwxrwx 1 root root 10 Jan 13 13:57 scsi-SATA_WDC_WD3201ABYS-_WD-WCARW3003070-part3 -> ../../sda3 lrwxrwxrwx 1 root root 9 Jan 13 13:57 usb-Generic_USB_CF_Reader_058F312D81B -> ../../sdd lrwxrwxrwx 1 root root 9 Jan 13 13:57 usb-Generic_USB_MS_Reader_058F312D81B -> ../../sdf ...
The PBD is created using xe pbd-create
# xe pbd-create host-uuid=6acdd0f6-cad4-4d46-b852-16c645e6c8b5 sr-uuid=4f9d6505-0f10-5e08-9629-4a4813ec57a7 device-config:device=/dev/disk/by-id/scsi-SATA_WDC_WD20EARX-00_WD-WCAZAJ973153-part3 7c37bb56-ee51-19b1-3df0-a5a4df9b385a
Then we can connect with xe pbd-plug
# xe pbd-plug uuid=7c37bb56-ee51-19b1-3df0-a5a4df9b385a
Remove a Storage Repository
To remove the Storage Repository added SR-uuid= 4f9d6505-0f10-5e08-9629-4a4813ec57a7 we have to reverse the actions previosuly made.
- unplung the Storage Repository PBD ( physical block device ) using pbd-unplug
- then remove SR with sr-forget
We can list PBD using xe pbd-list
[root@localhost ~]# xe pbd-list
uuid ( RO) : 2513bd51-bce5-18a5-040f-64ccf6822aec
host-uuid ( RO): 6acdd0f6-cad4-4d46-b852-16c645e6c8b5
sr-uuid ( RO): 66c01d4b-911d-8cfd-d5a0-d78a5ad2f732
device-config (MRO): location: /dev/xapi/block
currently-attached ( RO): true
uuid ( RO) : 8bb8f425-59ff-e8b2-edf2-627708adcfb2
host-uuid ( RO): 6acdd0f6-cad4-4d46-b852-16c645e6c8b5
sr-uuid ( RO): c425f5fb-1e60-685c-0a1c-6cc11a0087b7
device-config (MRO): location: /dev/xapi/cd
currently-attached ( RO): true
uuid ( RO) : 7c37bb56-ee51-19b1-3df0-a5a4df9b385a
host-uuid ( RO): 6acdd0f6-cad4-4d46-b852-16c645e6c8b5
sr-uuid ( RO): 4f9d6505-0f10-5e08-9629-4a4813ec57a7
device-config (MRO): device: /dev/disk/by-id/scsi-SATA_WDC_WD20EARX-00_WD-WCAZAJ973153-part3
currently-attached ( RO): true
uuid ( RO) : 52449e07-4f89-bc68-1a8e-3887b74cb875
host-uuid ( RO): 6acdd0f6-cad4-4d46-b852-16c645e6c8b5
sr-uuid ( RO): 37239476-c08f-ad02-c776-77830c73d6c6
device-config (MRO): device: /dev/disk/by-id/scsi-SATA_WDC_WD3201ABYS-_WD-WCARW3003070-part3
currently-attached ( RO): true
...
..
Unplug PBD with
xe pbd-unplug uuid=7c37bb56-ee51-19b1-3df0-a5a4df9b385a
Remove Storage Repository using
xe sr-forget uuid=4f9d6505-0f10-5e08-9629-4a4813ec57a7
Create a new Storage Repository
To create a new Storage Repository when you add a new disk you have to use the command xe sr-create. The command in question is an extremely dangerous command because it deletes the data on the partition or disk ( So beware).
The command syntax is:
xe sr-create name-label=<name> physical-size=<size> type=<type> content-type=<content_type> device-config:<config_name>=<value> [host-uuid=<Xen Cloud Platform host UUID>] [shared=<true | false>]
To check the disks accessible from XenServer use fdisk -l
[root@localhost ~]# fdisk -l Disk /dev/sda: 320.0 GB, 320072933376 bytes ... boot drive ... Disk /dev/sdb: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes ...
To get the UUID of the host refer to xe host-list
[root@localhost ~]# xe host-list uuid ( RO) : 6acdd0f6-cad4-4d46-b852-16c645e6c8b5 name-label ( RW): xs-602 name-description ( RW): Default install of XenServer Qualora si aggiunga un nuovo disco a XenServer per utilizzarlo come un nuovo Storage Repository (SR ) .
Create a new Storage Repository using a command like
xe sr-create name-label="xenloc2-2TBWD" type=lvm content-type=user device-config:device=/dev/sdb host-uuid=6acdd0f6-cad4-4d46-b852-16c645e6c8b5
Glossario
dom0 = privileged domain. It ‘s the Virtual Machine (VM) created by the hypervisor XenServe at boot. The privileged domain is the one that has direct access to the hardware and is responsible for launching other VM.
domU = unprivileged domU domain. All other instances of the virtual machine (VM) running other than dom0 are dominioU: it’is created a separate domain for each instance.
Host: the machine running XenServer
Guest: a Virtual Machine running in XenServer.
VM : Virtual Machine in XenServer is identified by a specific uuid and hosted on a Virtual Disk Image with its own vdi-uuid and is connected to dom0 via a VBD with his vdb-uuid.
VDI: Virtual Disk Image, the image or file is a virtual hard disk.
VDB: Virtual Block Device, a way to connect a VDI to a virtual machine
UUID: Universally unique identifier. A string of characters that XenServer, in this case, use to uniquely identify an object. You can read more at http://en.wikipedia.org/wiki/UUID
Altre risorse nle blog:
- XenServer eliminare VDI in uso utilizzando l’interfaccia comandi ( CLI )
- Mount veloce della partizione LVM di una VM in XenServer 5.6 « maurizio siagri
- xe_OpenXenManager – Ubuntu 12.04
- Differenze tra PVM (paravirtualization ) e HVM ( Xen Full virtualization )
- Debian 6.0 Squeeze 32 bit in XenServer 5.6 SP2 installazione e configurazione da zero
- XenServer economico per uso home lab versione 5.6 SP2
- Installare XenServer tools in Linux VM
- OpenXenManager
- lvm – logical volume manager
maurizio siagri 
This helped me greatly – thanks!