Solaris10如何确认DirectIO是否已经启用

对于Oracle而言，如果数据库存储在UFS文件系统上，启用DirectIO能够提高数据库性能。Oracle有个参数filesystemio_options可以控制数据库是否使用DirectIO. 如果在Oracle已经设置了使用DirectIO，怎样才能确认DirectIO是否真起作用了呢？在Solaris10上，可以通过dtrace来确认DirectIO是否已经启用。

1. DirectIO未启用的情况

检查filesystemio_options参数设置

SQL> show parameter filesystem NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ filesystemio_options string ASYNCH

ASYNCH表示数据库只启用了异步IO, 没有启用DirectIO.

Dtrace检查控制文件是否启用DirectIO

root@ofs001 # dtrace -n io:::start'/(args[0]->b_flags & B_READ) == 0 && args[2]->fi_pathname == "/oracle/data1/ACC010C1/control01.dbf"/{@[stack()] = count()}' dtrace: description 'io:::start' matched 6 probes ^C ufs`lufs_write_strategy+0x100 ufs`ufs_putapage+0x4f1 ufs`ufs_putpages+0x308 ufs`ufs_putpage+0x82 genunix`fop_putpage+0x28 genunix`vpm_sync_pages+0xa3 ufs`wrip+0x6f7 ufs`ufs_write+0x211 genunix`fop_write+0x31 genunix`pwrite+0x14f unix`sys_syscall+0x17b 44

系统调用了ufs_write, 表示DirectIO未启用

Dtrace检查数据文件是否启用DirectIO

在一个session上执行dtrace命令，另一session执行一个create table … as select * from xx;的命令.

root@ofs001 # dtrace -n io:::start'/(args[0]->b_flags & B_READ) == 0 && args[2]->fi_pathname == "/oracle/data2/ACC010C1/users01.dbf"/{@[stack()] = count()}'
dtrace: description 'io:::start' matched 6 probes
^Cufs`lufs_write_strategy+0x100ufs`ufs_putapage+0x501ufs`ufs_putpages+0x308ufs`ufs_putpage+0x82genunix`fop_putpage+0x28genunix`vpm_sync_pages+0xa3ufs`wrip+0x6f7ufs`ufs_write+0x211genunix`fop_write+0x31genunix`pwrite+0x14funix`sys_syscall+0x17b4ufs`lufs_write_strategy+0x100ufs`ufs_putapage+0x4f1genunix`pvn_vplist_dirty+0x3aaufs`ufs_putpages+0x1c2ufs`ufs_putpage+0x82genunix`fop_putpage+0x28ufs`ufs_fsync+0x1c4genunix`fop_fsync+0x28genunix`fdsync+0x28unix`sys_syscall+0x17b20系统调用ufs_write, 表示DirectIO未启用

2. DirectIO启用的情况

检查filesystemio_options参数设置

SQL> show parameter filesystem NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ filesystemio_options string SETALL

SETALL表示数据库同时启用了异步IO和DirectIO.

Dtrace检查控制文件是否启用DirectIO

root@ofs001 # dtrace -n io:::start'/(args[0]->b_flags & B_READ) == 0 && args[2]->fi_pathname == "/oracle/data1/ACC010C1/control01.dbf"/{@[stack()] = count()}'
dtrace: description 'io:::start' matched 6 probes
^Cufs`directio_start+0x12cufs`ufs_directio_write+0x788ufs`ufs_write+0x383genunix`fop_write+0x31genunix`pwrite+0x14funix`sys_syscall+0x17b39系统调用ufs_directio_write, 表示启用了directio.

Dtrace检查数据文件是否启用DirectIO

在一个session上执行dtrace命令，另一session执行一个create table … as select * from xx;的命令.

root@ofs001 # dtrace -n io:::start'/(args[0]->b_flags & B_READ) == 0 && args[2]->fi_pathname == "/oracle/data2/ACC010C1/users01.dbf"/{@[stack()] = count()}'
dtrace: description 'io:::start' matched 6 probes^Cufs`directio_start+0x12cufs`ufs_directio_write+0x788ufs`ufs_write+0x383genunix`fop_write+0x31genunix`pwrite+0x14funix`sys_syscall+0x17b17系统调用ufs_directio_write, 表示启用了directio.

转载于:https://www.cnblogs.com/cqubityj/p/3666775.html