HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes HP-UX 11i v3 October 2010 Web Release (B.11.
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Table of Contents Logical Volume Manager and MirrorDisk/UX Release Notes......................................5 About this document..............................................................................................................................5 LVM and MirrorDisk/UX overview........................................................................................................5 Overview of changes..................................................................................................
List of Tables 1 4 LVM Fixes in HP-UX 11i v3 October 2010 Web Release.................................................................
Logical Volume Manager and MirrorDisk/UX Release Notes About this document This document provides information about the Logical Volume Manager (LVM) and MirrorDisk/UX products in the October 2010 web release of HP-UX 11i v3. LVM and MirrorDisk/UX overview Logical Volume Manager (bundle BaseLVM) is the HP-UX default Volume Manager. It provides the user with flexibility in configuring and managing mass storage resources. In HP-UX 11i v3, the LVM kernel and commands are bundled with the core HP-UX product.
Table 1 LVM Fixes in HP-UX 11i v3 October 2010 Web Release (continued) Defect ID QXCR1001039721 Description In a configuration where large numbers of I/O are in progress in many logical volumes and automatic increase of pre-allocated extents for a space-efficient snapshot is enabled, the following message is logged in syslog: lvmpud->lvextend[25174]: "LogicalExtentsNumber" is not bigger than current setting.
Known problems Auto pre-allocation occurs for all unsharing if distributed snapshot has 2 PVs Defect ID: QXCR1001059016 Problem: The default threshold for a distributed, space-efficient snapshot is reached when the number of free extents in the pre-allocated pool is less than or equal to 20 percent of the total number of extents in the pre-allocated pool or when more than half of the number of free extents in the pre-allocated pool is from the same physical volume.
Corrective Action: Do one of the following: • • Use the lvchange command to change the permission of the space efficient snapshot to read-only to prevent the snapshot from becoming over-committed and inoperative due to any write on it. To prevent the snapshot from becoming over-committed and inoperative due to any write to its successor, add physical volume(s) to create necessary free extents in the volume group and deactivate and activate the volume group to allocate the pre-allocated extents.
Required hardware LVM and MirrorDisk/UX have no hardware requirements beyond the requirements of the HP-UX 11i v3 operating system. Both products run on all supported HP 9000 and HP Integrity servers. Required software Because LVM is installed with the HP-UX 11i v3 operating environment, there are no software requirements beyond the requirements of the HP-UX 11i v3 operating system. MirrorDisk/UX requires the BaseLVM product.
VxVM commands Several VxVM commands check whether a specified disk device is being used by LVM before overwriting it. For these commands to correctly check whether a device is part of a Version 2.x volume group, you must install the following patch: • PHCO_37836 for VxVM 4.1 • PHCO_40294 for VxVM 5.0 Required disk space Because LVM is installed with the HP-UX 11i v3 operating environment, it consumes no additional disk space. MirrorDisk/UX consumes no additional disk space aside from a license key.
Encrypted Volume and File System (EVFS) v1.1 and greater supports Version 2.x volume groups. Moving from HP-UX 11i v2 to HP-UX 11i v3 If you are migrating a system from HP-UX 11i v2 to HP-UX 11i v3, see the LVM migration white paper described in “Related documentation”. It contains information on migrating an LVM configuration from the legacy naming model to the agile naming model. Existing LVM configurations created on HP-UX 11i v2 continue to work on HP-UX 11i v3 under the legacy naming model.
NOTE: Patches PHKL_36745, PHCO_36744, and PHCO_37939 resolve this compatibility issue for HP-UX 11i v2. Installing these patches enables the creation and use of logical volumes up to 16 TB. • Striped Mirrors: Releases prior to HP-UX 11i v3 only support extent-based striping via the -D option to lvcreate. If a logical volume using simultaneous mirroring and non-extent-based striping is created on HP-UX 11i v3, attempts to import or activate its associated volume group will fail on a previous HP-UX release.
In addition, LVM user documentation is available in English at http://www.hp.com/go/ hpux-core-docs. Available documents include: • • • • • • • • • • • • • • HP-UX Logical Volume Manager and MirrorDisk/UX Release Notes (this version and previous versions) HP-UX System Administrator's Guide: Logical Volume Management (this document is localized) LVM 2.