I've attached 5 virtual disks to a Virtual Machine in Citrix XenServer. The VM has the xs-tools installed. Initially it said that it couldn't add so many disks. After I installed the xs-tools, it let me add all the disks.
But /dev
doesn't show all the disks. It shows these:
/dev/xvda
/dev/xvdb
/dev/xvdc
/dev/cdrom
Perhaps it is bound by the limits of an IDE bus? (3 disks + CD-ROM) If so, how does one change the VM to use SCSI?
Edit:
According to the documentation:
2.6.3. VM Block Devices
In the PV Linux case, block devices are passed through as PV devices.
XenServer does not attempt to emulate SCSI or IDE, but instead
provides a more suitable interface in the virtual environment in the
form of xvd* devices. It is also possible to get an sd* device using
the same mechanism, where the PV driver inside the VM takes over the
SCSI device namespace. This is not desirable so it is best to use xvd*
where possible for PV guests (this is the default for Debian and
RHEL).For Windows or other fully virtualized guests, XenServer emulates an
IDE bus in the form of an hd* device. When using Windows, installing
the Citrix Tools for Virtual Machines installs a special PV driver
that works in a similar way to Linux, except in the fully virtualized
environment.
Still, with 5 virtual disks attached, I don't see the other xvd devices.
Edit #2: (attached requested info)
Host Machine:
XenServer 6.1
Linux version 2.6.32.43-0.4.1.xs1.6.10.777.170770xen (geeko@buildhost) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-51)) #1 SMP Wed Apr 17 05:52:03 EDT 2013
Guest Machine:
CentOS release 6.4 (Final)
Linux version 2.6.32-358.6.2.el6.x86_64 (mockbuild@c6b8.bsys.dev.centos.org) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-3) (GCC) ) #1 SMP Thu May 16 20:59:36 UTC 2013
Output of 'fdisk -l' on Guest Machine:
Note, the disk beyond the first 3 attached are not displaying — there should be 4 100GB disks. (There are a total of 5 disks displayed in XenCenter — 16GB, 100GB, 100GB, 100GB, 100GB)
Disk /dev/xvdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xfb6c95b9
Device Boot Start End Blocks Id System
/dev/xvdb1 1 13054 104856223+ 83 Linux
Disk /dev/xvda: 17.2 GB, 17179869184 bytes
255 heads, 63 sectors/track, 2088 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e5f41
Device Boot Start End Blocks Id System
/dev/xvda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/xvda2 64 2089 16264192 8e Linux LVM
Disk /dev/xvdc: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xed249ced
Device Boot Start End Blocks Id System
/dev/xvdc1 1 13054 104856223+ 83 Linux
Disk /dev/mapper/vg_blue-lv_root: 14.6 GB, 14571012096 bytes
255 heads, 63 sectors/track, 1771 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/mapper/vg_blue-lv_swap: 2080 MB, 2080374784 bytes
255 heads, 63 sectors/track, 252 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
I see that the Linux versions say SMP. The Guest VM doesn't say "xen" in the name. However, I have already run yum install kernel-xen
. Could be a clue?
Best Answer
Same problem here. I think you will see error message in /var/log/messages
Disks in GUI are /dev/hda, /dev/hdb, /dev/hdc, but on RHEL < 6 it is /dev/xvda/ etc... Disk can be added manually from cli, if you name it as /dev/xvd .
Found this: http://forums.citrix.com/message.jspa?messageID=1692261 Check Albert Czarnecki answeres.
"As like I said your machine is running in HVM mode. You must run command and change from HVM to PV: xe vm-param-set uuid=your_machine PV-bootloader=pygrub HVM-boot-policy="" and then run again machine."
Check also https://www.linuxnet.ch/xenserver-howto-convert-hvm-to-pv-rhelsuse/
Edit: I tried that, and now all disks are visible and system is PV .
Quick summary (may vary):
Check if PV or HVM
Set PV:
After reboot: