VERITAS Volume Manager™ 3.
Disclaimer The information contained in this publication is subject to change without notice. VERITAS Software Corporation makes no warranty of any kind with regard to this manual, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. VERITAS Software Corporation shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this manual.
Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .v Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .v Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .v Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Full LVM Restoration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Example: displaying the vxvmconvert menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Example: listing disk information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preface This Guide describes how to migrate from HP-UX Logical Volume Manager (LVM) to VERITAS Volume Manager™ (VxVM®) and convert disks and volumes managed by LVM to VxVM. It includes information on differences between VxVM and LVM commands and terminology. This Guide also discusses the use of both graphical user interfaces: VERITAS Enterprise Administrator™ (VEA™), the Volume Manager GUI, and SAM (System Administration Manager), the Logical Volume Manager GUI.
Related Documents ◆ “Command Differences” describes the differences between LVM and VxVM commands. It also lists LVM tasks and equivalent or similar VxVM tasks. ◆ “SAM and the VEA” describes the usage of VERITAS Volume Manager’s GUI (VEA) and its relationship with HP-UX SAM (System Administration Manager). ◆ “Conversion Error Messages” describes the error messages that may be encountered during conversion and contains troubleshooting procedures.
Conventions Conventions The following table describes the typographic conventions used in this guide. Typeface Usage Examples monospace Computer output, file contents, files, directories, software elements such as command options, function names, and parameters Read tunables from the /etc/vx/tunefstab file. New terms, book titles, emphasis, variables to be replaced by a name or value See the User’s Guide for details.
Getting Help Getting Help If you have any comments or problems with VERITAS products, contact VERITAS Technical Support: ◆ U.S. and Canadian Customers: 1-800-342-0652 ◆ International Customers: +1 (650) 527-8555 ◆ Email: support@veritas.com For license information (U.S. and Canadian Customers): ◆ Phone: 1-925-931-2464 ◆ Email: license@veritas.com ◆ Fax: 1-925-931-2487 For software updates: ◆ Email: swupdate@veritas.
1 VxVM and LVM This chapter provides an overview of the VERITAS Volume Manager (also referred to as VxVM) and its features. A brief description of the benefits of migrating from the HP-UX Logical Volume Manager (LVM) to VxVM, and the coexistence of VxVM disks with LVM disks is also given.
Introducing the VERITAS Volume Manager ◆ Final 24 July 2002 The VERITAS Volume Manager is integrated with HP MC/ServiceGuard and ServiceGuard OPS Edition for High Availability, but requires a specific version of the ServiceGuard products. Refer to the VERITAS Volume Manager 3.5 for HP-UX Release Notes for details about the required version number, as well as the availability of specific features in your release.
Introducing the VERITAS Volume Manager Final 24 July 2002 improved I/O performance from disks with multiple concurrently available pathways by balancing the I/O load uniformly across multiple I/O paths to the disk device. LVM supports path failover but does not support I/O balancing. DMP support may be used with devices that show improved performance when I/O is balanced across the multiple paths such as xp256, EMC Symmetrix disk array, and other OEM array devices.
VxVM and LVM—Conceptual Comparison Final 24 July 2002 VxVM and LVM—Conceptual Comparison The following section compares the terminology used in LVM and VxVM at a conceptual level. For more information, refer to the glossary of this Guide for precise and detailed definitions of these terms. Table 1. A Conceptual comparison of LVM and VxVM LVM Term VxVM Term LVM VxVM Both LVM and VxVM enable online disk storage management. They both build virtual devices, called volumes, on physical disks.
VxVM and LVM—Conceptual Comparison Final 24 July 2002 Table 1. A Conceptual comparison of LVM and VxVM LVM Term VxVM Term Volume Group Disk Group LVM volume groups are conceptually similar to VxVM disk groups. An LVM volume group is the collective identity of a set of physical volumes, which provide disk storage for the logical volumes. A VxVM disk group is a collection of VxVM disks that share a common configuration.
Coexistence of VxVM and LVM Disks Final 24 July 2002 Table 1. A Conceptual comparison of LVM and VxVM LVM Term VxVM Term Mirrors Mirrors (Plexes) Both LVM and VxVM support mirrors. Mirrors can be used to store multiple copies of a volume’s data on separate disks. In LVM, you can create mirrors using the MirrorDisk/UX product. Mirrors allow duplicate copies of the extents to be kept on separate physical volumes. MirrorDisk/UX supports up to 3 copies of the data. A VxVM mirror consists of plexes.
Final 24 July 2002 Coexistence of VxVM and LVM Disks Both LVM and VxVM utilities are aware of the other volume manager, and will not overwrite disks that are being managed by the other volume manager. The administrative utilities (SAM and vmsa) recognize and identify all disks on the system (see Chapter , SAM and the VEA, for details). The vxvmconvert command is provided to enable LVM disks to be converted to a VxVM disk format without losing any data.
Coexistence of VxVM and LVM Disks 8 Final 24 July 2002 VERITAS Volume Manager Migration Guide
2 Converting LVM to VxVM This chapter explains how to convert your LVM configuration to a VxVM configuration and presents the following main topics: ◆ Converting Unused LVM Physical Volumes to VxVM Disks ◆ Converting LVM Volume Groups to VxVM Disk Groups ◆ Restoring the LVM Volume Group Configuration ◆ Examples The basic tools for conversion are the VxVM commands, vxvmconvert and vxdiskadm, and the LVM administrative utilities such as pvremove and vgcfgbackup.
Converting LVM Volume Groups to VxVM Disk Groups Final 24 July 2002 Removing LVM Disk Information To remove LVM disk information from the disks use the following command: # pvremove disk_name The pvremove command will not allow the removal of disk headers which indicate a Volume Group membership for the disk. If the disk fails pvremove for this reason, you should first make certain that the group membership information is stale.
Final 24 July 2002 Converting LVM Volume Groups to VxVM Disk Groups Note It is recommended that you read through this section carefully before beginning any volume group conversion. The conversion process involves many steps. Though there are tools to help you with the conversion, some of these steps cannot be automated. You should be sure to understand how the whole conversion process works, and what you will need to do in the process before beginning a volume group conversion.
Converting LVM Volume Groups to VxVM Disk Groups Final 24 July 2002 Note You can use the vxcp_lvmroot(1M) command to create a VxVM root disk on a spare physical disk from the contents of the existing LVM root disk. Similarly, you can use the vxres_lvmroot(1M) command to recreate an LVM root disk on a spare disk from the contents of the VxVM root disk. For more information, see the section “Rootability” in the “Administering Disks” chapter of the VERITAS Volume Manager Administrator’s Guide.
Final 24 July 2002 Converting LVM Volume Groups to VxVM Disk Groups Unlike LVM, VxVM does not support bad block revectoring at the physical volume level. If there appear to be any valid bad blocks in the bad block directory of any disk used in an LVM volumegroup, the group cannot be converted. See Appendix A, Conversion Error Messages, for actions to take in this situation. ◆ Not enough disk space on the root file system to save a copy of each physical disk’s LVM metadata.
Converting LVM Volume Groups to VxVM Disk Groups Final 24 July 2002 10. Restarting applications on the new VxVM volumes. 11. Tailoring your VxVM configuration. These steps are described in detail in later sections of this chapter. Annotated examples on how to use vxvmconvert are shown in “Examples” on page 24. For information on restoring back to your original LVM configuration refer to “Restoring the LVM Volume Group Configuration” on page 21. Conversion Steps Explained 1.
Converting LVM Volume Groups to VxVM Disk Groups Final 24 July 2002 changes are committed to disk. For more information, see “Converting LVM Volume Groups to VxVM Disk Groups” on page 10. The analysis option is useful when you have a large number of groups/disks for conversion and some amount of planning is needed before the actual conversion. Installations with many users or critical applications can use the analyze option on a running system. Then conversion downtime can be better planned and managed.
Converting LVM Volume Groups to VxVM Disk Groups Final 24 July 2002 Be sure to use the -f option to save the data into a file other than the default. vxvmconvert uses LVM utilities which themselves save the configuration using vgcfgbackup. If you do not use the -f option when you attempt to backup the configuration, the conversion process will overwrite your attempted backup.
Final 24 July 2002 Converting LVM Volume Groups to VxVM Disk Groups Non-file system back up If a logical volume you are converting does not contain a file system, and is being used directly by an application (such as a database application), use the backup facilities provided by the application. If no such facility exists, consider using the dd command. 5.
Converting LVM Volume Groups to VxVM Disk Groups Final 24 July 2002 Caution This method of resolving the naming problem has risks. The symbolic links can become stale. For example, if a database refers to /dev/vx/rdsk/vol1 through a symbolic link /dev/vg00/rvol1(“the old LVM name)”, and if the underlying VxVM volume configuration is changed in any way, the database could refer to a missing or different volume. Note You may want to use this symbolic link approach to ease the transition to VxVM.
Final 24 July 2002 Converting LVM Volume Groups to VxVM Disk Groups Conversion and Reboot During conversion, after the analysis phase is complete, the disks to be converted are deemed to be conversion ready. The vxvmconvert program asks if you are ready to commit to the conversion changes. If you choose to complete the conversion, the system will try to unmount all of the associated mounted file systems, stop and export the volume group, and then install the VxVM configuration.
Converting LVM Volume Groups to VxVM Disk Groups Final 24 July 2002 The details of the conversion process are shown in “Examples” on page 24. 8. Taking actions if conversion fails Conversion can fail for any of the reasons detailed in the “Volume Group Conversion Limitations” section. Messages from vxvmconvert will explain the type of failure, and any actions you can take before retrying the conversion. See “Conversion Error Messages” on page 65 for complete details of specific error messages. 9.
Final 24 July 2002 Restoring the LVM Volume Group Configuration Note You must only rename objects in the VxVM configuration after you are fully satisfied with that configuration. In particular, you should never use menu option 3 of vxvmconvert (Roll back) after name changes. If you have chosen to set up symbolic links to the VxVM volumes as described in “step 5. Planning for new VxVM logical volume names,” avoid renaming VxVM objects.
Restoring the LVM Volume Group Configuration Final 24 July 2002 Note Restoring user data using the vgrestore and frecover method will result in the loss of all user data changes made since the conversion, and the loss of all new volumes created since the conversion. In other words, this method of restoring data will take you back to exactly where you were before the conversion was done.
Restoring the LVM Volume Group Configuration Final 24 July 2002 This “snapshot” is kept on the root file system. The presence of this snapshot should not be taken as assurance that full off-line backups will not be needed. See “4. Backing up your LVM configuration and user data” for specific information on backups. To rollback to LVM from the VxVM conversion, run vxvmconvert and choose option 3. See “Example: VxVM to LVM rollback” on page 36 for illustration.
Examples Final 24 July 2002 2. Use the recovery method to restore user or application data. In preparation for conversion, the recovery method should have been done with the standard backups you made in preparation for conversion. The following example shows an frecover from the fbackup example in “step 4. Backing up your LVM configuration and user data.
Examples Final 24 July 2002 c0t9d0 c0t10d0 c0t11d0 disk01 - rootdg - LVM online online Device to list in detail [
,none,q,?] (default: none) none Example: listing LVM volume group information To list LVM volume group information, use the listvg option of vxvmconvert. Select the listvg option from the vxvmconvert Main Menu: Menu: Volume Manager/LVM_Conversion/ListLVMVolumeGroups # listvg Use this menu option to display a list of LVM volume groups.Examples Final 24 July 2002 Total PE Alloc PE Free PE Total PVG --- Logical volumes --LV Name LV Status LV Size (Mbytes) Allocated PE Used PV --- Physical Extent --LV Name LV Status LV Size (Mbytes) Current LE Allocated PE Used PV --- Physical volumes --PV Name PV Status Total PE Free PE 250 250 0 0 /dev/vg08/lvol1 available/syncd 500 125 1 /dev/vg08/lvol2 available/syncd 500 125 125 1 /dev/dsk/c0t8d0 available 250 0 List another LVM Volume Group? [y,n,q,?] (default: n) Select an operation to perform
Examples Final 24 July 2002 ? ?? q Display help about menu Display help about the menuing system Exit from menus Select an operation to perform: 1 Analyze one or more LVM Volume Groups Menu: Volume Manager/LVM_Conversion/Analyze_LVM_VGs Use this operation to analyze one or more LVM volume groups for possible conversion using the VxVM Volume Manager. This operation checks for problems that would prevent the conversion from completing successfully.
Examples Final 24 July 2002 Example of a failed analysis # vxvmconvert Volume Manager Support Operations Menu: VolumeManager/LVM_Conversion 1 Analyze LVM Volume Groups for Conversion 2 Convert LVM Volume Groups to VxVM 3 Roll back from VxVM to LVM list List disk information listvg List LVM Volume Group information ? Display help about menu ?? Display help about the menuing system q Exit from menus Select an operation to perform: 1 Analyze one or more LVM Volume Groups Menu: Volume Manager/LVM_Conversion/A
Final 24 July 2002 Examples Analysis of vg08 found insufficient Private Space for conversion SMALLEST VGRA space= 176 RESERVED space sectors = 78 PRIVATE SPACE/FREE sectors = 98 AVAILABLE sector space = 49 AVAILABLE sector bytes = 50176 RECORDS neededs to convert = 399 MAXIMUM records allowable= 392 The smallest disk in the Volume Group (vg08) does not have sufficient private space for the conversion to succeed.
Examples Final 24 July 2002 Group conversion may require a reboot for the changes to take effect. For this release, only Non-root LVM Volume Groups are allowed to be converted. More than one Volume Group or pattern may be entered at the prompt.
Examples Final 24 July 2002 The conversion process will update the /etc/fstab file so that volume devices are used to mount the file systems on this disk device. You will need to update any other references such as backup scripts, databases,or manually created swap devices. If you do not like the default names chosen for the corresponding logical volumes, you may change these to whatever you like using vxedit.
Examples Final 24 July 2002 Example of a failed conversion # vxvmconvert Volume Manager Support Operations Menu: VolumeManager/LVM_Conversion 1 Analyze LVM Volume Groups for Conversion 2 Convert LVM Volume Groups to VxVM 3 Roll back from VxVM to LVM list List disk information listvg List LVM Volume Group information ? Display help about menu ?? Display help about the menuing system q Exit from menus Select an operation to perform: 2 Convert one or more LVM Volume Groups Menu: VolumeManager/LVM_Conversion/
Final 24 July 2002 Examples The following disk has been found in the vg08 volume group and will be configured for conversion to a VxVM disk group. c4t8d0 A new disk group dg08 will be created and the disk device c4t8d0 will be converted and added to the disk group with the disk name dg0801. The c4t8d0 disk has been configured for conversion. The first stage of the conversion operation has completed successfully.
Examples Final 24 July 2002 every volume removed, the number of Database records required would be reduced by three. This is only a rough approximation, however. Hit RETURN to continue. Example: list, listvg, and vxprint outputs of an LVM volume group before and after conversion The examples given below, shows the vxvmconvert listvg, list, and vxprint output for an LVM volume group vg08 converted to a VxVM disk group dg08.
Examples Final 24 July 2002 list, listvg outputs are from within the vxvmconvert command. vxprint is a command line command. Example of the listvg output after conversion of vg08: LVM VOLUME GROUP INFORMATION Name Type Physical Volumes vg00 ROOT c0t5d0 vg09 Non-Rootc0t9d0 Volume Group to list in detail: None Note Note that vg08 is no longer listed under LVM information.
Examples Final 24 July 2002 The plex dg08lv1-01 is associated with volume dg08lv1, and maps the entire address range of the volume. Associated with the plex is one subdisk, dg0801-01 which maps the plex address range from 0 to the entire length of the plex, i.e. 102400 blocks. As implied by the root of its name, the subdisk dg0801-01 uses an extent from the VxVM disk dg0801.
Examples Final 24 July 2002 Rollback other LVM Volume Groups? [y,n,q,?] (default: n) Example: Invoking the vxvmconvert menu with vxinstall The example below describes the conversion of a LVM volume group vg01 with disks c5t3d0 and c5t4d0 into the VxVM rootdg disk group using vxinstall -C.
Examples Final 24 July 2002 The disk device c5t4d0 will be converted and added to the disk group rootdg with the disk name disk02. The c5t4d0 disk has been analyzed and prepared for conversion. The first stage of the conversion operation has completed successfully. If you commit to the changes hereafter, the system will attempt to umount all of the associated file systems, stop and export each Volume Group, and then attempt to complete the conversion without having to reboot the system.
General Information Regarding Conversion Speed Final 24 July 2002 Volume Manager: Initializing c5t4d0 as a converted LVM disk. Volume Manager: Reconfiguration will be done without rebooting. The Volume Manager is now reconfiguring (initialization phase)... Volume Manager: Adding disk01 (c5t3d0) as a converted LVM disk. Volume Manager: Adding disk02 (c5t4d0) as a converted LVM disk.
General Information Regarding Conversion Speed ◆ Final 24 July 2002 mirrored volumes. Mirrored volumes typically do not take more time to convert than simple volumes. Volumes that are mirrored and striped at the same time would take longer, but LVM currently does not allow this. Currently, after conversion, mirrored volumes are not automatically synchronized because a large mirror could take hours to complete.
3 Command Differences This chapter describes the differences between LVM and VxVM commands, and tasks. It includes a task comparison chart which lists some of the tasks performed using LVM with a near equivalent task performed using VxVM. It also provides a list of VxVM tasks which are not available with LVM, and the LVM features currently not supported in VxVM.
LVM and VxVM Command Equivalents Final 24 July 2002 Table 2. Command Comparison LVM Description/Action lvlnboot Creates root, primary and secondary swap and dump volumes. It also creates boot areas on the disk. lvcreate Creates a logical volume. VxVM Description/Action There is no equivalent command for this release. vxassist Creates volumes with the make parameter. Example: vxassist make vol_name 100M layout=stripe lvextend Increases disk space allocated to a logical volume.
LVM and VxVM Command Equivalents Final 24 July 2002 Table 2. Command Comparison LVM Description/Action VxVM Description/Action lvsplit Splits a mirrored logical volume into two logical volumes. vxassist snapshot The snapshot operation takes one of the attached temporary mirrors and creates a new volume with the temporary mirror as its one plex.
LVM and VxVM Command Equivalents Final 24 July 2002 Table 2. Command Comparison LVM Description/Action VxVM pvmove vxevac Moves allocated physical extents from source to destination vxsd mv within a volume group. Description/Action Moves volumes off a disk. Performs volume operations on a subdisk. Moves the contents of old subdisk onto the new subdisks and replaces old sub disk with the new subdisks for any associations. The vxdiskadm script presents a menu of possible operations to the user.
LVM and VxVM Command Equivalents Final 24 July 2002 Table 2. Command Comparison LVM Description/Action VxVM Description/Action vgreduce Reduces a volume group by removing one or more disks from it. vxdg rmdisk Removes disks from a disk group. vxdisk rm Removes the specified disk access record by disk access name. vxdiskadm Option 3 in the vxdiskadm menu removes disks. vxinfo Displays information about volumes. vgscan Scans all disks and looks for logical volume groups.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 2. Command Comparison LVM Description/Action VxVM Description/Action lvchange, lvextend, lvcreate, lvreduce Performs operations on logical volumes. vxvol Operates on volume objects. No LVM command vxsd Operates on subdisk objects. No LVM command vxmend Fixes simple misconfigurations.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example LVM Create an LVM disk. pvcreate /dev/rdsk/disk_name VxVM Bring a disk under Volume Manager control. vxdiskadd device_name LVM Create a volume group vgcreate /dev/vol_grp /dev/dsk/disk_name VxVM Create a disk group. vxdg init disk_group disk_name Option 1 in the vxdiskadm menu adds a disk and initializes it. Option 1 in the vxdiskadm menu performs this task.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example LVM Extend a logical volume or increase space allocated to a logical volume. lvextend -l 50 /dev/vol_grp/lvol_name Increase the volume by or to a given length.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example LVM Export and deactivate an LVM volume group, and its associated logical volumes. vgchange -a n vol_group Deport a disk group to disable access to the specified disk group. A disk group cannot be deported if any volumes in the disk group are currently open. vxdg deport disk_group LVM Back up volume group configuration information.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example LVM Extend a volume group by adding LVM disks to the volume group. vgextend /dev/vol_grp/\ /dev/dsk/disk_name VxVM Add one or more disks to the disk group. vxdiskadd disk_name Option 1 in the vxdiskadm main menu performs this task.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example LVM Create a logical volume in LVM volume group. lvcreate -L vol_size /dev/vol_grp VxVM Create a volume of one of these layout types: A concatenated volume vxassist make vol_name length A striped mirror volume vxassist make vol_name length layout=mirror, stripe A RAID-5 volume vxassist make vol_name length layout=raid5 LVM Display information about logical volumes.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example LVM Display information about volume groups. vgdisplay -v /dev/vol_grp VxVM Display disk group information. vxdisk list vxprint -g disk_group vxdg list Display information about a specific disk group. vxdisk list disk_group LVM Display information about physical volumes. pvdisplay /dev/dsk/disk_name VxVM Display information about Volume Manager volumes.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description LVM Set up alternate links to a physical volume. If a disk has two controllers, you can make one primary and the other an alternate link.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example LVM Increase the number of mirror copies. lvextend -m 2 /dev/vol_grp/lvol_name VxVM Add mirrors to a volume or increase the number of plexes. vxassist mirror vol_name LVM Convert a mirrored logical volume into two logical volumes. Split a logical volume. lvsplit -s backup /dev/vol_grp/lvol_name VxVM Snapshot a volume and create a new volume.
Comparison of LVM and VxVM Tasks Final 24 July 2002 Table 3. LVM and VxVM Task Comparison Task Type Description Example VxVM Resynchronize operations for the named volumes, or for volumes residing on the named disks. vxrecover -s vol_name If no medianame or volume operands are specified, then the operation applies to all volumes. LVM Start a volume. lvchange -a y /dev/vol_grp/lvol_name VxVM Start a volume. vxrecover -s vol_name vxvol start vol_name LVM Stop a volume.
Tasks With No Direct LVM Equivalents Final 24 July 2002 Tasks With No Direct LVM Equivalents The following table lists tasks which have no direct LVM equivalent. Most of these tasks can be performed either with the VxVM GUI (VEA), or the command line interface. For more information, refer to the VERITAS Volume Manager User’s Guide—VEA and the VERITAS Volume Manager Administrator’s Guide. Table 4.
Final 24 July 2002 Existing Features in LVM not supported in VxVM Table 4. Additional VxVM Tasks with no LVM equivalents Task Description Example Create a snapshot copy of a volume. vxassist snapshot vol_name temp_vol_name Recover a volume. vxrecover -g disk_group volume medianame vxmend fix clean plex_name Repair a mirror vxplex att plex_name Disable a mirror vxplex det plex_name Remove a log from a volume. vxassist remove log vol_name Move a subdisk.
Existing Features in LVM not supported in VxVM Final 24 July 2002 Table 5. LVM features and VxVM equivalents Bad media block relocation. 58 VxVM relocates whole subdisks. Smaller granularity relocation is not supported. The bad block reallocation feature does not exist in VxVM because the vectoring of bad blocks is now done by most hardware.
4 SAM and the VEA This chapter describes the VERITAS Volume Manager GUI, the VERITAS Enterprise Administrator™ (VEA™), and its relationship with the LVM GUI, and the System Administration Manager (SAM). The following topics are discussed in this chapter: ◆ Listing Disk Devices in SAM ◆ Listing Volume Groups and Disk Groups in SAM ◆ Listing Logical Volumes in SAM SAM and the VEA coexist as independent entities. The VEA recognizes and labels LVM volumes and disks, but does not manage them.
Listing Disk Devices in SAM Final 24 July 2002 Listing Disk Devices in SAM To list disk devices in SAM, from the Disks and File Systems SAM area, select Disk Devices. The Disk Devices screen lists the system’s disk devices. When VxVM is installed on the system, SAM includes a “Use” column to indicate whether a disk is under LVM or VxVM control, or whether it is unused. If a VxVM disk is online and part of a disk group, the disk group name is listed under the “Volume Group” column.
Final 24 July 2002 Listing Volume Groups and Disk Groups in SAM Listing LVM Volume Groups and VxVM Disk Groups with SAM Chapter 4, SAM and the VEA 61
Listing Logical Volumes in SAM Final 24 July 2002 Listing Logical Volumes in SAM To list logical volumes in SAM, from the Disks and File Systems SAM area, select Logical Volumes. The Logical Volumes screen lists the LVM logical volumes and the VxVM volumes on the system. The “Type” column indicates whether a volume is controlled by LVM or VxVM. The “Use” column shows whether a volume is in use and if so, what it is used for. The following figure shows a Logical Volumes screen for the same example system.
Final 24 July 2002 Listing Logical Volumes in SAM Listing LVM Logical Volumes and VxVM Volumes with SAM Chapter 4, SAM and the VEA 63
Listing Logical Volumes in SAM 64 Final 24 July 2002 VERITAS Volume Manager Migration Guide
A Conversion Error Messages This appendix lists the error messages that you may encounter when conversting LVM volume groups to VxVM disk groups and volumes. For each error message, a description is provided of the problem, and the action that you can take to troubleshoot it.
Final 24 July 2002 Analysis shows that there is insufficient private space available to convert this volume group ◆ Description The error message indicates the maximum amount of records that can be stored in the private space, and how many records are needed to convert this particular volume group. ◆ Action You can reduce the number of records needed by reducing the number of logical volumes in volume group by combining some of the logical volumes together.
Final 24 July 2002 f. Remove the dummy link to the raw device, for example: # rm /dev/rdsk/temp g. Restore the headers from the lvmconf backup, for example: # vgcfgrestore -n /dev/vg01 /dev/rdsk/c0t0d0 h. Activate the volume group and integrity check the data or recover from backup. The conversion process was unable to deactivate the volume group vol_grp_name ◆ Description This indicates that the conversion process cannot deactivate the volume group.
Final 24 July 2002 vgchange: Couldn't deactivate volume group /dev/vol_grp ◆ Description The conversion process was unable to deactivate the volume group. The conversion cannot proceed without reboots being done. If you choose to not reboot your system, the conversion is aborted. ◆ Action The system responds with an option to complete the conversion by rebooting the system.
Glossary block A unit of space for data on a disk, typically having a size of 1024-bytes. Dirty Region Logging Dirty Region Logging (DRL) is an optional property of a volume, used to provide a speedy recovery of mirrored volumes after a system failure. DRL keeps track of the regions that have changed due to I/O writes to a mirrored volume. file system The organization of files on storage devices.
logical Extent A set of logical blocks that maps to one physical extent and is a basic unit of access in a logical volume. LVMREC The LVM record, which is an identifier that is set on each disk when it is initialized the first time by LVM. There are two copies of the LVMREC; one is at sector 8, while the other is at sector 72. mirror disk/UX HP-UX software product that allows disk mirroring as part of LVM functionality. Mirror Disk/UX allows up 2 mirror copies in a volume.
set of continuous physical extents [PEs] Set of physical sectors (blocks) contained within a single physical volume. A physical extent is a specific, contiguous region of the disk where data resides. This is of a constant size usually of 4 MB and has no partitions. VGRA The Volume Group Reserved Area (VGRA) is a region on an LVM disk that holds LVM configuration information and is at a fixed location. The location of this fixed location depends upon whether the disk is a boot disk or a non-boot disk.
72 VERITAS Volume Manager Migration Guide
Index rename 56 replace 56 disk group 47 rename 56 disk groups 1 disk headers 10 disks 1 coexistence 6 mirroring 50 display disk group 51 DMP 56 logical volume 51 physical volume 51 volume 51 VxVM volumes 51 DMP display 56 Multipathing 53 Dynamic Multipathing 46, 53 A alternate links 53 analyze 26 B back up volume group 49 Backup vgcfgbackup 15 C coexistence VxVM and LVM disks 6 commands vxedit 41 configuration LVM 9 configuration VxVM 9 conversion errors 65 speed 39 vxvmconvert 11 D deactivate disk group
this LVM Volume Group 67 vgchange Couldn’t deactivate volume group /dev/vol_grp 68 vxdiskadm or vxvmconvert is already being run and these programs cannot run concurrently 68 Example analyze LVM groups 24 conversion 24 failed coversion 24 list 24 list disk information 24 list LVM volume group information 24 listvg 24 VLM to VxVM 24 vxprint output 24 example Failed Analysis 24 export volume group 49 extend volume group 50 Logical Volume 4, 5 logical volume convert 54 split 54 synchronize 54 Logical Volume M
Private Region 5 pvchange 43 pvcreate 43 pvdisplay 43 pvmove 44 R RAID-5 46 reduce 48 volume group 50 remove disk 52 volume 52 volume group 49, 52 rename disk group 56 repair mirror 57 restore volume group 49 resynchronize volumes 54 root disk configuring for VxVM 12 reconfiguring for LVM 12 root disks mirroring 50 rootability configuring a VxVM root disk 12 restoring a LVM root disk 12 root disk 11 root volume 11 S SAM 46, 59 vgdisplay 14 split subdisk 57 Storage 46 Storage Administrator 46 subdisk join 57
VxVM names symbolic link 18 VxVM volumes 76 resynchronize 54 vxvmconvert 26 vxvol 43, 46 VERITAS Volume Manager Migration Guide
