98
Chapter 9. Managing GFS
9.7.3.1. Usage
Setting the
inherit_directio
flag
gfs_tool setflag
inherit_directio
Directory
Setting the
inherit_directio
flag
gfs_tool clearflag
inherit_directio
Directory
Directory
Specifies the directory where the
inherit_directio
flag is set.
9.7.3.2. Example
In this example, the command sets the
inherit_directio
flag on the directory named
/gfs1/data/
.
gfs_tool setflag inherit_directio /gfs1/data/
9.8. Data Journaling
Ordinarily, GFS writes only metadata to its journal. File contents are subsequently written to disk by
the kernel’s periodic sync that flushes file system buffers. An
fsync()
call on a file causes the file’s
data to be written to disk immediately. The call returns when the disk reports that all data is safely
written.
Data journaling can result in a reduced
fsync()
time, especially for small files, because the file data
is written to the journal in addition to the metadata. An
fsync()
returns as soon as the data is written
to the journal, which can be substantially faster than the time it takes to write the file data to the main
file system.
Applications that rely on
fsync()
to sync file data may see improved performance by using data
journaling. Data journaling can be enabled automatically for any GFS files created in a flagged direc-
tory (and all its subdirectories). Existing files with zero length can also have data journaling turned on
or off.
Using the
gfs_tool
command, data journaling is enabled on a directory (and all its subdirectories)
or on a zero-length file by setting the
inherit_jdata
or
jdata
attribute flags to the directory or
file, respectively. The directory and file attribute flags can also be cleared.
9.8.1. Usage
Setting and Clearing the
inherit_jdata
Flag
gfs_tool setflag
inherit_jdata
Directory
gfs_tool clearflag
inherit_jdata
Directory
Setting and Clearing the
jdata
Flag
gfs_tool setflag
jdata
File
gfs_tool clearflag
jdata
File
Содержание GFS 5.2.1 -
Страница 1: ...Red Hat GFS 5 2 1 Administrator s Guide...
Страница 8: ......
Страница 14: ...vi Introduction...
Страница 24: ...10 Chapter 1 GFS Overview...
Страница 36: ...22 Chapter 4 Initial Configuration...
Страница 84: ...70 Chapter 6 Creating the Cluster Configuration System Files...
Страница 96: ...82 Chapter 8 Using Clustering and Locking Systems...
Страница 126: ...112 Chapter 10 Using the Fencing System...
Страница 132: ...118 Chapter 11 Using GNBD...
Страница 144: ...130 Appendix A Upgrading GFS...
Страница 184: ...170 Appendix B Basic GFS Examples...
Страница 190: ......
Страница 192: ...178...