Installation guide

4.6.5.3 Possible Problems Accessing Physical Block 0 with LSM

Physical block 0 on Tru64 UNIX disks is typically write protected by default.

If a disk is added to LSM by using the voldiskadd utility, physical block

0 is skipped. However, if a partition that includes physical block 0 is

encapsulated into LSM by using the volencap, vollvmencap,or

voladvdomencap utility, physical block 0 is not skipped. This is not a

problem because the ﬁle system software already skips block 0 and does not

write to it.

A problem can occur when an LSM volume that contains a write-protected

block 0 is dissolved and its disk space is reused for a new purpose. Neither

the new application nor LSM know about the write-protected physical disk

block 0 and a write failure can occur.

To ﬁx this problem, use the following steps to remove the write-protected

physical disk block 0 from the LSM disk before it can be assigned to the new

volume:

1. Use the voldg and voldisk commands to remove the disk from LSM.

2. Use the voldiskadd command to add either a speciﬁc partition of the

disk or the entire disk to LSM.

4.6.5.4 Using LSM with SWXCR-P(A/B) and SWXCR-E(A/B) RAID

Controllers

When you create an LSM mirror using a disk that is conﬁgured as Just-a-

Bunch-of-Disks (JBOD) with either the SWXCR-P or SWXCR-E RAID

controllers, a disk failure requires that you reconﬁgure the disk on the

controller. The disk is in an unusable state once it is set off line by the

controller and cannot be used by LSM until it is reconﬁgured. Refer to the

StorageWorks RAID Array 200 Subystem Family Installation and

Conﬁguration Guide.

4.6.5.5 Enabling LSM After Installation Requires Rebuilding the Kernel

If you use the setld utility to install LSM after you originally install Tru64

UNIX, you must rebuild the system kernel to enable LSM.

To rebuild the kernel, run the doconfig utility with no command ﬂags.

Be sure to select all the appropriate options for your system, and be ready to

edit the conﬁguration ﬁle as needed to reimplement any changes required by

your system.

Note that the doconfig menu display does not include LSM. However, the

doconfig utility will build a kernel that includes LSM. Refer to the

Logical Storage Manager guide for more information.

Base System Software Notes 4–39