Operating system and file system capacity
Operating systems and file systems when initializing a P-VOL will consume some Dynamic Provisioning pool space. Some combinations will initially take up little pool space, while other combinations will take as much pool space as the virtual capacity of the DP-VOL.
The following table shows the effects of some combinations of operating system and file system capacity. For more information, contact your Hitachi Data Systems representative.
|
OS |
File System |
Metadata Writing |
Pool Capacity Consumed |
|---|---|---|---|
|
Windows Server 2003 and Windows Server 2008* |
NTFS |
Writes metadata to first block. |
O Small (one page) If file update is repeated, allocated capacity increases when files are updated (overwritten). Therefore, the effectiveness of reducing the pool capacity consumption decreases. |
|
Linux |
XFS |
Writes metadata in Allocation Group Size intervals. |
O Depends upon allocation group size. The amount of pool space consumed will be approximately [DP-VOL Size]*[42 MB/Allocation Group Size] |
|
Ext2 Ext3 |
Writes metadata in 128-MB increments. |
O About 33% of the size of the DP-VOL. The default block size for these file systems is 4 KB. This results in 33% of the DP-VOL acquiring HDP pool pages. If the file system block size is changed to 2 KB or less then the DP-VOL Page consumption becomes 100%. |
|
|
Solaris |
UFS |
Writes metadata in 52-MB increments. |
X Size of DP-VOL. |
|
VxFS |
Writes metadata to the first block. |
O Small (one page). |
|
|
AIX |
JFS |
Writes metadata in 8-MB increments. |
X Size of DP-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. |
|
JFS2 |
Writes metadata to the first block. |
O Small (one page). |
|
|
VxFS |
Writes metadata to the first block. |
O Small (one page). |
|
|
HP-UX |
JFS (VxFs) |
Writes metadata to the first block. |
O Small (one page). |
|
HFS |
Writes metadata in 10-MB increments. |
X Size of DP-VOL. |
|
|
Explanatory notes: O: Indicates an effective reduction of pool capacity. X: Indicates no effective reduction of pool capacity. |
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