HP XP Racks - Manual (Page 66)

Pool Capacity Consumed Metadata Writing File System OS
effectiveness of reducing the pool
capacity consumption decreases.
O Writes metadata in Allocation
Group Size intervals. XFS Linux
Depends upon allocation group size.
The amount of pool space consumed
will be approximately [THP V-VOL
Size]*[42 MB/Allocation Group Size]
O Writes metadata in 128-MB
increments. Ext2
Ext3 About 33% of the size of the THP
V-VOL.
The default block size for these file
systems is 4 KB. This results in 33% of
the THP V-VOL acquiring THP pool
pages. If the file system block size is
changed to 2 KB or less then the THP
V-VOL Page consumption becomes
100%.
X Writes metadata in 52-MB
increments. UFS Solaris
Size of THP V-VOL.
O Writes metadata to the first
block. VxFS
Small (one page).
X Writes metadata in 8-MB
increments. JFS AIX
Size of THP V-VOL.
If you change the Allocation Group
Size settings when you create the file
system, the metadata can be written
to a maximum interval of 64 MB.
Approximately 65% of the pool is
used at the higher group size setting.
O Writes metadata to the first
block. JFS2
Small (one page).
O Writes metadata to the first
block. VxFS
Small (one page).
O Writes metadata to the first
block. JFS (VxFs) HP-UX
Small (one page).
X Writes metadata in 10-MB
increments. HFS
Size of THP V-VOL.
Explanatory notes:
O: Indicates an effective reduction of pool capacity.
X: Indicates no effective reduction of pool capacity.
*See “Formatting LDEVs in a Windows environment” (page 136)
66 Configuring thin provisioning