|
|
United States-English | |
|
|
 |
|
HP Integrity Virtual Machines: Installation, Configuration, and Administration > Chapter 6 Creating Virtual Storage Devices
Configuring Integrity VM Storage |
|
|
This section describes how to plan and set up Integrity VM storage, including: When you configure storage for a virtual machine, consider the following: The following sections explain each of these considerations. Before you configure virtual machine storage, make sure the VM Host storage can be supported by the virtual machine.
To meet the performance requirements of applications running in guests, consider the potential performance of each type of Integrity VM storage device. Different types of virtual media have different effects on the performance of the virtual device because they communicate differently with the VM Host to complete virtual machine I/O operations. To understand the effect of the virtual device type on potential performance, consider the Integrity VM storage I/O stack illustrated in Figure 6-1. For a virtual I/O operation to be completed, it has to travel round trip between the virtual storage adapter and the VM Host physical storage device. The longer the path is, the longer it takes for virtual I/O to be completed. As shown in Figure 6-1, a virtual I/O operation must traverse each software layer in order, from where it originates to the physical media. For example, a virtual I/O operation for a Virtual FileDisk must traverse any logical volume managers the file system is on, any disk partitions the logical volumes are on, and the disk drivers that control the whole disk where the disk partitions reside. Therefore, in general, the higher the virtual media is in the VM Host I/O stack, the slower it operates. The simplified I/O stack in Figure 6-1 does not completely illustrate all the choices that can affect the performance:
For further information on tuning performance at each software layer on the VM Host, see the Integrity VM white papers on http://docs.hp.com. When you configure virtual devices, consider how the virtual media maps to the physical storage. All virtual media connects to a piece of physical media somewhere in the data center. You can help ensure the best performance by understanding the impact of the physical storage and the way I/O accesses it. It is important to know exactly where the virtual media is located on physical storage devices. With Integrity VM, a single physical disk might be sliced into partitions, logical volumes or files. Slicing up physical disks increases utilization, but it can affect the performance of the physical device. The guest OS treats the virtual disk as a whole disk, not as a part of a physical one. Over-slicing physical storage can overload a physical device's ability to handle virtual I/O that is meant for whole disks. Figure 6-2 shows a common mistake of overdriving physical storage with multiple guest OS boot disks, which are often I/O intensive. Provide workloads that the physical devices can handle for all the virtual devices layered on top of them. Use performance tools on the VM Host, like sar(1M), to see how the physical storage is keeping up with the virtual device demands. The way the virtual media I/O gets to the physical storage backing it is also an important consideration. As shown in Figure 6-1, all virtual I/O goes through a general VM Host I/O services layer that routes the virtual I/O to the correct VM Host interface driver. The interface driver then controls the physical I/O adapter to issue virtual I/O to the physical storage device. By load balancing across these physical adapters, virtual I/O bottlenecks can be eliminated at the physical hardware layers, thereby increasing performance. Load balancing can be done by installing a multipath solution on the VM Host. See “VM Storage Multipath Solutions” for help with selecting a multipath solution for a virtual media type. The performance of attached devices is largely determined by the type of physical device attached to the virtual machine. Tapes, media changers, and CD/DVD burners are inherently slow devices, not significantly impacted by the software overhead of Integrity VM. For load balancing and higher availability for virtual machines, consider using a multipath solution on the VM Host. Currently there are no multipath solutions for the attachable device types of tapes, media changers, and CD/DVD burners. However, there are several VM Host multipath options for virtual devices. Multipath solutions are supported on the VM Host only, not on virtual machines, for the following reasons:
Each multipath software solution for HP-UX 11.23 interacts at different layers on the I/O stack. Since Integrity VM also interacts with different layers in the I/O stack, only certain options apply to each virtual media type. Table 6-1 lists the multipath solutions to use on a VM Host for each type of virtual storage media: Table 6-1 Multipath Solutions
Although Table 6-1 lists the possible solutions for each virtual media type, it cannot determine what is supported on your specific VM Host configuration. Each multipath solution is only supported for specific hardware and software. The solution vendors provide this information for their multipath products. Review the installation and release notes of these products carefully to form a valid VM Host configuration before using it for any virtual machine. Some multipath options do not work together and they all have different load balancing features. Before you decide how to divide VM Host storage, consider the impact on the management of the storage subsystem. A VM Host administrator manages VM storage to make sure virtual media is allocated safely. This begins with understanding the VM Host I/O stack and knowing where the virtual media is being allocated from. Figure 6-3 shows an example of a VM Host I/O stack as it applies to a single LUN: The virtual machine is allocated a logical volume from the LUN for a Virtual LvDisk.
The remaining parts of the disk can be allocated to a virtual machine. Those parts that are no longer available include the files that were on the logical volume, the disk partition that makes up part of volume group, and the whole disk that makes up part of the volume group. If any of these parts are allocated for other virtual devices, data corruption can occur on the Virtual LvDisk. Those parts that are still available for reallocation include other logical volumes that are on the disk, files that are on those other logical volumes on the disk, and the other disk partition that is not part of the volume group that the Virtual LvDisk is on. These pieces can be allocated without data corruption problems because they do not overlap with the Virtual LvDisk. Beyond avoiding sub-LUN collisions, whole LUN collisions also need to be avoided. The same storage resource, virtual or attached, cannot be specified more than once to the same virtual machine. Under HP-UX 11.23, most storage device files are defined per path. Be careful not to specify a given device twice. Figure 6-4 shows an example of two device files, /dev/rdsk/c6t2d0 and /dev/rdsk/c11t2d0 pointing to the same physical disk. Once the /dev/rdsk/c6t2d0 device file is specified for a Virtual Disk, the /dev/rdsk/c11t2d0 device file is no longer available. Also, the same storage resource, virtual or attached, cannot be simultaneously shared between virtual machines, unless otherwise specifically exempted. Figure 6-5 shows a Virtual LvDisk being shared across virtual machines, which is not supported. As these examples illustrate, it is important to know where storage is allocated from to avoid data corruption with virtual machines or even the VM Host. Use the HP System Administration Manager or the sam(1M) utility. The sam utility provides the ability to track disk devices, volume groups, logical volumes, and file systems. It attempts to consolidate multipaths to not show disks more than once. Additionally, it provides the ability to annotate devices so that VM Host administrators can see exactly which virtual machines are using what VM Host storage devices. The sam utility does not track individual disk partitions. However, you should use all of the parts of a single disk on a single virtual machine when you are dividing up the disk. Allocating different parts of the same disk to different virtual machines makes it difficult to manage and to isolate problems. Depending on how you set up storage for a virtual machine, the resulting configuration can be more or less difficult to change. The ability to change virtual media depends on the type of virtual media used. Whole disks are not normally adjustable in terms of size, but some high-end storage enclosures may permit the adjustment of a LUN without losing that LUN's data. Disk partitions are not adjustable without losing the disk's data. However, soft partitions, such as logical volumes, are adjustable without losing any data. Finally, files can be changed easily with VM Host file system commands. No changes to any virtual media can take place on the VM Host until the virtual device that uses the media is removed from the active VM. Attempts to change virtual devices that have I/O active on them is denied by the hpvmmodify command. Once an active virtual machine is allocated virtual media for a virtual device, that virtual machine owns that media and can access it any time. VM Host administrators need to coordinate with VM guest administrators about active virtual machine changes, if the two roles are served by different individuals. This coordination may also be necessary for attached I/O devices. Once a VM Host device is attached to the virtual machine, it is controlled and owned by that virtual machine. Modifications to the attached device, like changing a tape, can be done physically without detaching the device from the guest. However, such changes may need to be coordinated with the VM Host administrator, especially if the guest administrator has no physical access to the device attached to the virtual machine. All types of virtual storage devices can be added and removed dynamically from virtual machines. That is, virtual disks, virtual DVDs, tapes, media changers, and CD/DVD burners are all hot-swappable. However, the virtual storage adapters are currently not hot-swappable. Therefore, if all the virtual storage adapters are full, you must reboot the virtual machine when you add additional devices. Some virtual devices take longer to set up than others. Whole disks are very easy to set up because they require nothing more than a character device file. This is usually created automatically when the VM Host system is booted. Disk partitions require the creation of the hard disk partitions and their corresponding device files. Though not difficult, this can be time consuming. Logical volume creation is relatively simple. Logical volumes are used widely on HP-UX systems. The sam utility or the Veritas Enterprise Administrator can be used to create logical volumes. With experience, you can use logical volume commands more quickly. Creating files for virtual devices is not hard, but takes time. Files are usually placed on top of logical volumes, so you might have to create a logical volume first. Use sam to accomplish this. To create empty files for virtual disks, use the hpvmdevmgmt command (see “Managing the Device Database”). To create ISO files from physical CD/DVD media for use in virtual DVDs, use the mkisofs(1M) or the dd(1M) utility. For attached devices, the effort and time to set them up is spent in the creation of the HP-UX pass-through device files that point to the devices being attached. Once understood, making HP-UX pass-through device files is a fast, simple process. If device drivers for the devices are installed on the VM Host, use the hpvmdevmgmt command to quickly create the device files. Otherwise, see scsi_ctl(1M) for information about creating pass-through device files using mknod(1M). When you add or modify a virtual device, you must enter a resource statement (rsrc). The resource statement can specify either virtual network devices (as described in “Creating Virtual Networks”), or virtual storage devices. This section describes how to enter resource statements for use with the hpvmcreate command (described in Chapter 3) and the hpvmmodify command (described in Chapter 8). The resource statement specifies the virtual storage device that will be seen by the virtual machine and how it maps to the physical storage device on the VM Host. The outline of a complete resource statement for specifying a virtual storage device is the following:
where:
All virtual storage is addressed from virtual PCI buses. There are 8 PCI buses on the Integrity VM virtual platform. Each PCI bus has 8 slots into which virtual PCI adapters can be placed. One such adapter, simply called scsi, is an emulated single-ported parallel SCSI MPT storage adapter that can be used to connect 15 SCSI target devices to a virtual machine. A VM Host administrator specifies this SCSI MPT adapter using the following:
Where:
A PCI function number is not specified. It is implicitly zero because the virtual MPT storage adapter supports only a single channel. A virtual SCSI MPT adapter can only be added to a virtual machine if it has a device connected to it. Not all device types are virtualized. Disk and DVD devices are virtual device types, whose virtual media comes from the VM Host. Tapes, changers, and burners are physical VM Host devices. For these attached devices, the physical SCSI IDs do not determine their place on the virtual bus. Each VM storage device is backed by some VM Host storage entity. A VM Host entity is defined on the VM Host with a system file, which is used by Integrity VM and the VM Host operating system in processing I/O to and from that storage entity. A VM Host administrator specifies these storage entities using the following specification:
where
Not all virtual device types support all VM Host storage types (see “Integrity VM Storage Implementations”). Complete VM storage resource statements are discussed in the next section. This subsection provides information on formulating complete valid resource statements for Integrity VM storage devices. To specify an Integrity VM storage device for a virtual machine, use a complete valid resource statement with the hpvmcreate or hpvmmodify command. The resource statement is a combination of the VM guest resource specification (described in“VM Guest Storage Specification”) and the VM Host Storage Specification (described in “VM Host Storage Specification”). This section provides examples of complete resource statements for each of the following types of virtual storage devices: A virtual machine can have up to 30 devices total (number of virtual and attached devices). The maximum size of a virtual storage resource is 2 TB. The minimum size of a virtual storage resource is 512 bytes for virtual disk and 2048 bytes for a virtual DVD. Do not specify the same storage resource, virtual or attached, for the same virtual machine more than once (see “VM Storage Management”). Unless otherwise noted, storage resources, virtual or attached, cannot be simultaneously shared by virtual machines. All multipath products for storage resources must run on the VM Host; multipath solutions are not supported in a virtual machine. All multipath solutions used on the VM Host must be in valid supported configurations before being used for Integrity VM storage resources (see “VM Storage Multipath Solutions”). The resource statements in the following subsections do not contain VM hardware addressing. The PCI bus, PCI slot, and SCSI target numbers are optional. A Virtual Disk is an emulated SCSI disk whose virtual media comes from a VM Host disk LUN. The VM Host disk LUN is specified using a character device file. The character device file must be owned by the HP-UX sdisk driver. Virtual Disk resources cannot be shared simultaneously across active virtual machines. Only one active virtual machine at time can be given a particular Virtual Disk resource. Virtual Disk resources can be changed dynamically among active virtual machines. To prevent virtual media conflicts that can result in data corruption, a proper accounting of how the VM Host whole disks are allocated for use by Virtual Disks needs to be done, as described in “VM Storage Management”. To provide a multipath solution for a Virtual Disk, see “VM Storage Multipath Solutions”. The Virtual Disk resource statement takes the form of:
Where /dev/rdsk/cXtYdZ is an HP-UX character sdisk device file. These device files can be located for a VM Host LUN using the ioscan command. These system files are installed and removed using the insf and rmsf commands, respectively. Device files are created automatically by the VM Host for any storage it sees during boot. New devices connected or created after boot time, require the use of ioscan and insf to create the new sdisk device files. Old device files for storage not longer present can be removed with rmsf. For example:
In this example, the Virtual Disk Resource Statement is disk:scsi::disk:/dev/rdsk/c19t0d2. If you are using EMC PowerPath or HP SecurePath/Autopath for a Virtual Disk, use their respective commands to ensure the sdisk device files chosen are enabled for use by the multipath product. Consult the multipath vendor's documentation for more information. A Virtual PartDisk is an emulated SCSI disk whose virtual media comes from a VM Host disk partition. The VM Host disk partition is specified using a character device file. The character device file is owned by the HP-UX sdisk driver. Virtual PartDisks cannot be shared simultaneously across active virtual machines. Only one active virtual machine at time can be given a particular Virtual PartDisk resource. Virtual PartDisk resources can be changed dynamically between active virtual machines (see “Using Integrity VM Storage”). VM Host disk partitions must be managed to prevent virtual media conflicts that can result in data corruption. To help with the accounting, HP recommends that all disk partitions on a single VM Host disk LUN be used with a single virtual machine. See “VM Storage Management” for more information on tracking virtual media allocation To provide a multipath solution for a Virtual PartDisk, see “VM Storage Multipath Solutions”. To create a disk partition on a VM Host disk LUN, use the idisk utility. This utility was originally designed to create boot disks, but you can use it to create hard disk partitions on any disk. When you create hard disk partitions, you must decide how many partitions to create and what sizes they should be. Changing the partitioning after creation wipes out all data on the disk. If you need more flexibility, use logical volumes, which provide soft partitioning that can be adjusted after creation. After making these decisions, use an editor to create an input file to the idisk command. The input file begins with the total number of partitions to create, followed by the partition types and sizes. The partitions types of EFI, HPUX, and DUMP do not matter to Integrity VM and have no effect on the data stored on the partitions. Because the idisk command was originally designed for creating a boot disk, it forces the first partition type to be an EFI type. There are no restrictions on partition sizes based on partition types. For example, create an input file as follows:
After you complete the input file, use it with the idisk command to create the partitions on a VM Host disk. For example:
After the partitions are created, run the ioscan, rmsf and insf utilities to create the sdisk device files, as follows:
The new sdisk partitions files (those ending with “s”), are numbered in order with respect to the idisk input file:
The Virtual PartDisk resource statement form is:
Where the /dev/rdsk/cXtYdZsV is an HP-UX character sdisk device file for a hard disk partition.
In this example, the Virtual PartDisk Resource Statement is disk:scsi::disk:/dev/rdsk/c4t0d0s. If you are using EMC PowerPath or HP SecurePath/Autopath for a Virtual PartDisk, use their respective commands to ensure the sdisk device files chosen are enabled for use by the multipath product. Consult the multipath vendor's documentation for more information. A Virtual LvDisk is an emulated SCSI disk whose virtual media is provided by a VM Host logical volume. To specify a VM Host logical volume, use a character device file. The character device file is owned by either LVM or VxVM. Virtual LvDisks cannot be shared simultaneously across active virtual machines. Only one active virtual machine at time can be given a particular Virtual LvDisk resource. Virtual LvDisk resources can be changed dynamically between active virtual machines (see “Using Integrity VM Storage”). To prevent data corruptions, keep an account of logical volumes for Virtual LvDisks. To help with the accounting, use all logical volumes within a given volume group for a single virtual machine. When logical volumes are configured this way, you only have to keep track of the volume groups to prevent media conflicts. See “VM Storage Management” for information about tracking virtual media allocation. Logical volumes can be created using the sam utility or the Veritas Enterprise Administrator. Alternatively, logical volumes can be created using the commands available with the volume manager. All logical volumes are created on top of volume group types, which are created on top of disk partitions or whole disks. The sizes of the logical volumes come from the space available from their respective volume group types; that logical volume size can be increased without loss of data in the volume. The character devices for the logical volumes are created by their respective volume managers at the time the logical volume is created. If you are using LVM, the Virtual LvDisk resource statement takes the following form:
Where /dev/vg_name/rlvol_name is an LVM character device file for rlvol_name on vg_name. To display the LVM character device file name, enter the following command:
In this example, the Virtual LvDisk Resource Statement is disk:scsi::lv:/dev/lvrackA/rdisk2. To use VxVM, the Virtual LvDisk resource statement takes the form of:
Where /dev/vx/rdsk/dg_name/v_name is a VxVM character device file for volume v_name on disk group dg_name. To display the VxVM character device file name, enter the following command:
To use VxVM, the Virtual LvDisk resource statement is disk:scsi::lv:/dev/vx/rdsk/VxvmTest1/vxvm_2. For information about multipath solutions for Virtual LvDisks, see “VM Storage Multipath Solutions”. A Virtual FileDisk is an emulated SCSI disk whose virtual media comes from a VM Host file. The VM Host file is specified using the absolute pathname to the file. The file can be on a VxFS file system locally mounted on the VM Host. NFS file systems are not supported for Virtual FileDisks. Virtual FileDisks cannot be shared simultaneously across active virtual machiness. Only one active virtual machine can be given a particular Virtual FileDisk resource at a time. Virtual FileDisk resources can be changed dynamically between active virtual machines (see “Using Integrity VM Storage”). The file systems used for Virtual FileDisks need to be managed to prevent data corruptions. To help with accounting, it is recommended that all files under a given directory be used with a single virtual machines. Additionally, it may help to allocate file directories from complete logical volumes or whole disks to make the accounting even easier. See “VM Storage Management” for more details. The Virtual FileDisk resource statement takes the form of:
Where the /pathname/file specifies the VM Host file used as virtual media. A VxFS file system can be created on top of a whole disk, disk partition, or logical volume. For files over 2GB, VxFS requires the file system be marked with a largefiles option. The mkfs command can be used to create the VxFS file systems directly. Once the file systems are created, mount can be used to mount them onto the VM Host file system. Alternatively, if using logical volumes to create the file system on, the volume manager GUIs like sam can be used to create the file systems and their mount points, when the logical volumes are created. In any case, once the file system is mounted, empty files for Virtual FileDisk can be created using hpvmdevmgt.
In this example, the Virtual FileDisk resource statement is disk:scsi::file:/fdev/frackA/disk1. Multipath options for a Virtual FileDisk device are discussed in “VM Storage Multipath Solutions”. A Virtual DVD is an emulated SCSI DVD-ROM with virtual media that comes from a disc inside of a CD/DVD drive on the VM Host. The VM Host CD/DVD drive is specified using an HP-UX sdisk character device file. While the Virtual DVD is read-only, the slowness of the physical VM Host CD/DVD drives prohibits them from being shared across active virtual machines. Thus only one active virtual machine at time should be given a particular Virtual DVD resource. Virtual DVD resources can be changed dynamically between active virtual machines (see “Using Integrity VM Storage”). The Virtual DVDs, being read-only, do not require management to prevent conflicts writing to the device. However, to prevent potentially sensitive information from being accessed by the wrong virtual machine, make sure you know which virtual machine currently owns the device before you load a CD/DVD. This information can be found on the VM Host with the hpvmstatus commands. The Virtual DVD resource statement takes the form of:
Where /dev/rdsk/cXtYdZ is an HP-UX character device file representing a VM Host CD/DVD drive. Typically, the HP-UX sdisk character file will already be created before booting the VM Host. If it is not, it can be created and managed using the ioscan, insf, and rmsf utilities. For example:
In this example, the Virtual DVD resource statement is dvd:scsi::disk:/dev/rdsk/c0t0d0. For a Virtual DVD to be recognized by a virtual machine, physical media must be present inside the VM Host CD/DVD drive. If media is not added at virtual machine start time, it may be inserted into the VM Host CD/DVD drive after the virtual machine is already up. A rescan by the guest OS picks up the new media and adds the Virtual DVD to the virtual machine. If for some reason the VM Host Administrator requires control of the VM Host CD/DVD drive claimed by a virtual machine but has no media for the VM Host CD/DVD drive, then a Virtual NullDVD should be specified (see “Virtual NullDVDs”). Physical media can then be inserted into the VM Host CD/DVD drive and become virtual media for a Virtual DVD using the hpvmmodify or the virtual console's insert command (see “Guest Administrator”). After the Virtual DVD is in the virtual machine, the VM Host CD/DVD drive is locked. The VM Host CD/DVD drive is automatically unlocked when the virtual machine is shut down. The VM Host CD/DVD can also be changed while the virtual machine is up using the virtual console's eject command. Once ejected, the Virtual DVD will turn into a Virtual NullDVD and the VM Host CD/DVD drive will unlock. After you place physical media in the VM Host's CD/DVD drive, use the virtual console's insert command to turn a Virtual NullDVD back to a Virtual DVD, relocking the VM Host CD/DVD drive. Most physical VM Host CD/DVD devices on HP Integrity servers have only one path to them. As such, no multipath software is available on the VM Host for them. A Virtual FileDVD is an emulated SCSI DVD-ROM with virtual media that comes from a VM Host ISO file. The VM Host ISO file is specified using the absolute pathname to the ISO file. The file can be on a VxFS file systems locally mounted on the VM Host. NFS file systems are not supported for Virtual FileDVDs. The Virtual FileDVD resource statement takes the following form:
Where the /pathname/file.ISO specifies the VM Host ISO file to use as virtual media. A VM Host ISO file can be created using the mkisofs utility or by using the dd command to copy CD/DVD media to a file. The VxFS file system should be enabled to support largefiles, because ISO files tend to be over 2 GB in size. All the ISO files that are useful to a guest OS should be placed in the same directory to take advantage of dynamic changes using the virtual console (see “Modifying VM Storage Devices”). The ISO files should be marked with proper permissions; they must not be world writable. For example:
In this example, the Virtual FileDVD Resource Statement is: dvd:scsi::file:/var/opt/hpvm/ISOimages/hpux/0603-FOE-D1.iso. Virtual FileDVDs, like all files, can take advantage of the multipath options with which the file system is created. See “VM Storage Multipath Solutions” for details. Virtual FileDVDs are read-only and are sharable across active virtual machines. Use the hpvmdevmgmt command to mark them sharable. To prevent media conflicts, you must manage Virtual FileDVDs carefully (see “VM Storage Management”). You can see where the file system directory where the ISO file resides using the guest's virtual console. To simplify accounting, allocate file directories from complete logical volumes or whole disks. A Virtual NullDVD is an emulated SCSI DVD-ROM with no virtual media currently present. The next media selection may come from a VM Host CD/DVD drive or VM Host ISO file, depending on how the Virtual NullDVD is configured. Once the next media is selected, the Virtual NullDVD turns into either a Virtual DVD (see “Virtual DVDs”) or a Virtual FileDVD (see “Virtual FileDVDs”) device. As such, a Virtual NullDVD is a transitory state of an empty virtual DVD type. The choice of how to configure a Virtual NullDVD depends on the access that the VM Host administrator gives to the guest administrator. Virtual DVD changes can be initiated from the virtual console (see “Guest Administrator”). All virtual DVD changes by the guest administrator are constrainted by the actions of the VM Host administrator. If the VM Host administrator gives access to the guest administrator to load and unload physical media on the VM Host CD/DVD drive, the Virtual NullDVD is set up with the following form of the resource specification:
Where /dev/rdsk/cXtYdZ is an HP-UX character sdisk file that points to the VM Host CD/DVD drive. This is the same as setting up a Virtual DVD (see “Virtual DVDs”), except that the VM Host CD/DVD might not contain media. The media is expected to come from the guest administrator, who should have access to the VM Host to make such physical media changes. For example:
In this example, the Virtual NullDVD resource statement is dvd:scsi::null:/dev/rdsk/c0t0d0. If the VM Host administrator does not want to give access to the VM Host CD/DVD drive to the guest administrator, you can set up a Virtual NullDVD to a file system directory containing the ISO files that the guest administrator wants to access. This resource statement would take the following form:
Where /pathname is the file system directory where the ISO files are located. This is the same as setting up a Virtual FileDVD (see “Virtual FileDVDs”), except that the file is not specified. By specifying a file directory, the guest administrator can choose which ISO files to use from the virtual console. The file directory must be a locally mounted VxFS file system. NFS file systems are not supported. If the ISO files are world writable, they are not available from the virtual console. For the following ISO files:
The Virtual NullDVD resource statement is dvd:scsi::file:/var/opt/hpvm/ISO-images/hpux/. You can configure the Virtual NullDVD to be sharable or have multipath options. If the Virtual NullDVD device is configured to use the VM Host CD/DVD device, it is not sharable and no multipath options are available. If the Virtual NullDVD is configured to use a file system directory, it is sharable and you can use multipath options (see “VM Storage Multipath Solutions”). To mark the directory sharable across virtual machines, use the hpvmdevmgmt command. For example:
For more information about using the hpvmdevmgmt command, see “Managing the Device Database”. Virtual NullDVDs require no additional management beyond that required for the Virtual DVD (see “Virtual DVDs”) or Virtual FileDVD (see “Virtual FileDVDs”) types they become. Integrity VM allows you to attach physical VM Host backup device types to virtual machines. The VM Host backup device types are tapes, media changers, and CD/DVD burners. These devices are specified on the VM Host using HP-UX sctl device files. The guest OS running on the virtual machine has full control over an attached physical device. Therefore, the guest OS must support the device being attached. See the device's product documentation for a list of supported guest OS drivers. The resource statements for attached devices take the following forms depending upon device type:
Where /dev/rscsi/cXtYdZ is an HP-UX sctl device file to the device type specified. To create an HP-UX sctl device file, follow these steps:
Attached devices cannot be shared simultaneously across active virtual machines. Only one active virtual machine can be given a particular attached device at a time. However, like virtual devices, attached devices can be attached and detached dynamically across active virtual machines (see “Using Integrity VM Storage”). Also, as the device is being attached to a virtual machine, it cannot be opened by the VM Host at the time of or during attachment. Because tapes, media changers, and CD/DVD burners are not virtualized, media changes with them must be done physically. Therefore, all media changes with attached devices must be done by individuals with access to that physical storage. Changes to attached devices may require the device to be unlocked from an active guest OS. Attached devices remain in the last lock state the guest OS put it in when the device is detached or the virtual machine is shut down. Empty devices are attached and are not locked. No multipath solutions are available for attached devices on the VM Host. No multipath products are supported in the virtual machine. Manage attached devices to prevent the wrong virtual machines from viewing sensitive information. You can display which virtual machines are currently using attached devices using the hpvmstatus command. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 Printable version |
|
|
|
|
|
|||||||||||||||
|
|||||||||||||||
