HP-UX LVM Supported Limits (September 2008)

ManualsBrandsHP ManualsSoftwareHP-UX 11i Volume Management (LVM/VxVM) Software

HP-UX LVM Supported Limits

Table of Contents

Abstract ..............................................................................................................................................2

Introduction .........................................................................................................................................2

Supported Limits for Version 1.0 Volume Groups .....................................................................................3

Calculating an Optimal Extent Size for a Version 1.0 Volume Group......................................................4

Sample shell script ............................................................................................................................4

Supported Limits for Volume Group Version 2.0 and 2.1 ..........................................................................6

Calculating an Optimal Size for a Version 2.0 and 2.1 Volume Group...................................................7

Determining LVM’s Maximum Limits on a System......................................................................................8

Glossary .............................................................................................................................................9

For More Information..........................................................................................................................10

Call to Action ....................................................................................................................................10

Summary of content (10 pages)

PAGE 1
HP-UX LVM Supported Limits Table of Contents Abstract ..............................................................................................................................................2 Introduction .........................................................................................................................................2 Supported Limits for Version 1.0 Volume Groups .....................................................................................
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Abstract Starting with HP-UX 11i v2 (11.23), the supported limits of LVM volume groups has gradually increased. In HP-UX 11i v3 (11 .31), LVM delivers significant performance, scalability, usability, and availability enhancements. After the initial release of HP-UX 11iv3 in February 2007, three updates occurred in September 2007, March 2008, and September 2008. This white paper summarizes the LVM supported limits for different volume group versions supported on HP-UX releases.
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Supported Limits for Version 1.0 Volume Groups The following table summarizes the supported limits in LVM for HP-UX 11.00 and later releases. Unless noted otherwise, the values are the same across releases. Parameter Max number of Version 1.
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Calculating an Optimal Extent Size for a Version 1.0 Volume Group Sometimes when creating a Version 1.0 volume group (VG), the vgcreate command might abort with a message indicating that the extent size is too small (too big error or a more informative error (with newer patches) explaining that the VGRA is too big). In this situation, you must manually increase the extent size and re-issue the vgcreate command.
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length = 16 + 2 * roundup(2 + (roundup(36 + ((3 * roundup(pvs, 32)) / 8) + (roundup(pxs, 8) / 8) * pvs, BS) + roundup(16 * lvs, BS) + roundup(16 + 4 * pxs, BS) * pvs) / BS, 8); if (length > 768) { printf("Warning: A bootable PV cannot be added to a VG \n" "created with the specified argument values. \n" "The metadata size %d Kbytes must be less \n" "than 768 Kbytes.\n" "If you do not want a boot disk in this \n" "VG, do not use the '-B' option during pvcreate(1M) \n" "for the PVs to be part of this VG.
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Supported Limits for Version 2.0 and 2.1 Volume Groups The following table summarizes the supported limits in LVM for Version 2.0 and 2.1 VGs. Unless noted otherwise, the values are the same across releases. Note: Creation of Version 2.x VGs and the inherent limitations are very different from Version1.0 VGs. For more information, see the “LVM Version 2.0 volume groups in HP-UX 11i v3” white paper.
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Calculating an Optimal Size for a Version 2.0 and 2.1 Volume Group Like Version 1.0 VGs, there is a relationship between extent size and maximum VG size. There is also a limitation on the number of extents an individual VG can contain. To determine the proper size, the vgcreate command has a new –E option. This option displays the maximum VG size based on the given physical extent size or minimum physical extent size based on the max VG size.
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Determining LVM’s Maximum Limits on a System The March 2008 update to HP-UX 11i v3 (11.31) introduced a new command that enables the system administrator to determine the maximum LVM limits supported on the target system for a given volume group version. The lvmadm command displays the implemented limits for Version 1.0 and Version 2.x VGs. It is impossible to create a VG that exceeds these limits.
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Glossary KB MB GB TB PB A kilobyte unit of information equal to 210 or 1024 bytes A megabyte unit of information equal to 220 or 1,048,576 bytes A gigabyte unit of information equal to 230 or 1,073,741,824 bytes A terabyte unit of information equal to 240 or 1,099,511,627,776 bytes A petabyte unit of information equal to 250 or 1,125,899,906,842,624 bytes 9
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For More Information To learn more about some of the LVM features, see the following documents on the HP documentation website: http://docs.hp.com (Use search with the given name of the whitepaper) http://www.docs.hp.com/en/oshpux11iv3#LVM%20Volume%20Manager • • • • • • • LVM Version 2.