Hi all,
QUESTION:
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The following are comments from an EMC HP-UX HEAT Report. The first statement states the "Patch PHKL_35970" disables use of BBR. The later statements go on to say that BBR should be set to NONE. Does BBR still need to be set to none if PHKL_35970 is installed?
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NOTICE : Patch PHKL_35970 is installed. This patch disables use of BBR. If software bad block relocation is used on a Physical Volume greater than 256GB, then data corruption can occur when bad block relocation is performed on blocks outside of the 256 GB range. Software bad block relocation makes use of the bad block directory. This uses 28 bits for a block address, therefore can only support PVs up to 256 GB. When blocks above the 256GB range are mapped by the bad block directory, a truncated block address is used, causing data corruption. Modern disks and disk arrays use hardware bad block relocation. Software bad block relocation is redundant in these disks, therefore LVM will no longer create new software relocation entries in the bad block directory. LVM will continue to honor existing software relocation entries, with the exception of software relocation entries on large (>256 GB) PVs. For large PVs, we will return a MEDIA error on any blocks that have previously been relocated, since the entries can potentially map to multiple blocks.
NOTICE : LVM Bad block reallocation (BBR) should be disabled and the LVM mechanism for marking blocks defective when a medium error is returned should be disabled for all HP LVM logical volumes residing on EMC Symmetrix and EMC Clariion devices.
NOTICE : There is a difference between setting BBR to off and setting BBR to NONE :
off : Prevent bad block relocation - Upon a media failure, LVM will mark the failed block as bad in the Bad Block Directory, but will NOT attempt to relocate the bad block to a new location on disk. Future I/O requests which contain the bad block will return with an I/O error.
I can't get a definitive answer on this and was wondering could anyone give me one.
Thanks.
QUESTION:
------------------------------------
The following are comments from an EMC HP-UX HEAT Report. The first statement states the "Patch PHKL_35970" disables use of BBR. The later statements go on to say that BBR should be set to NONE. Does BBR still need to be set to none if PHKL_35970 is installed?
*************
NOTICE : Patch PHKL_35970 is installed. This patch disables use of BBR. If software bad block relocation is used on a Physical Volume greater than 256GB, then data corruption can occur when bad block relocation is performed on blocks outside of the 256 GB range. Software bad block relocation makes use of the bad block directory. This uses 28 bits for a block address, therefore can only support PVs up to 256 GB. When blocks above the 256GB range are mapped by the bad block directory, a truncated block address is used, causing data corruption. Modern disks and disk arrays use hardware bad block relocation. Software bad block relocation is redundant in these disks, therefore LVM will no longer create new software relocation entries in the bad block directory. LVM will continue to honor existing software relocation entries, with the exception of software relocation entries on large (>256 GB) PVs. For large PVs, we will return a MEDIA error on any blocks that have previously been relocated, since the entries can potentially map to multiple blocks.
NOTICE : LVM Bad block reallocation (BBR) should be disabled and the LVM mechanism for marking blocks defective when a medium error is returned should be disabled for all HP LVM logical volumes residing on EMC Symmetrix and EMC Clariion devices.
NOTICE : There is a difference between setting BBR to off and setting BBR to NONE :
off : Prevent bad block relocation - Upon a media failure, LVM will mark the failed block as bad in the Bad Block Directory, but will NOT attempt to relocate the bad block to a new location on disk. Future I/O requests which contain the bad block will return with an I/O error.
I can't get a definitive answer on this and was wondering could anyone give me one.
Thanks.