ORA-27102 問題解決

54xw

   今天上午有一個(gè)數(shù)據(jù)庫恢復(fù)的工作，目的是要把預(yù)生產(chǎn)庫的數(shù)據(jù)庫恢復(fù)到生產(chǎn)庫去。用的是ASM,磁盤組，參數(shù)文件什么都創(chuàng)建好了，嘗試啟動(dòng)instance,卻發(fā)現(xiàn)instance啟動(dòng)不了�！�

 

SQL*Plus: Release 11.2.0.1.0 Production on Thu Aug 4 22:25:08 2011

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup nomount;
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
SQL> exit

 

  首先想到是內(nèi)存不足了，于是用free查看，發(fā)現(xiàn)空閑的內(nèi)存只有876mb , 而大部份內(nèi)存是被cache了　。

root@hostname:~#free -m
             total       used       free     shared    buffers     cached
Mem:         32055      31179        876          0        443      25223
-/+ buffers/cache:       5513      26542
Swap:         8191        316       7875

  嘗試釋放cache里的內(nèi)存：

 

root@hostname:~#sync
root@hostname:~#echo 3 > /proc/sys/vm/drop_caches
root@hostname:~#free -m
             total       used       free     shared    buffers     cached
Mem:         32055       8325      23730          0          1       4214
-/+ buffers/cache:       4108      27947
Swap:         8191        316       7875

 

　比較釋放前后的值，可以發(fā)現(xiàn)已經(jīng)有近20G內(nèi)存釋放了。重新啟動(dòng)instance，發(fā)現(xiàn)仍然不能啟動(dòng)。

 

SQL*Plus: Release 11.2.0.1.0 Production on Thu Aug 4 22:25:08 2011

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup nomount;
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
SQL> exit

 

 

　先把/proc/sys/vm/drop_caches改回默認(rèn)值再說：

root@hostname:~#echo 0 > /proc/sys/vm/drop_caches

 

　又想到linux里的核心參數(shù)，于是參考了預(yù)生產(chǎn)庫的的參數(shù)配置：

# Oracle Kernal Parameters
#kernel.shmall = 2097152
#kernel.shmmax = 2147483648
kernel.shmmni = 4096
kernel.sem = 256 96000 100 1024
fs.file-max = 6553600
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 4194304
kernel.msgmni = 2878

　但發(fā)現(xiàn)參數(shù)文件設(shè)定的值和系統(tǒng)的實(shí)際完全不一樣�。�

hostname:elcaro:$ cat /proc/sys/kernel/shmall
4294967296
hostname:elcaro:$ cat /proc/sys/kernel/shmmax
68719476736

 

　于是將生產(chǎn)庫的核心參數(shù)改為和預(yù)生產(chǎn)庫一樣，問題解決：

#Oracle Kernal Parameters
#kernel.shmall = 2097152
kernel.shmall = 4294967296
#kernel.shmmax = 2147483648
kernel.shmmax = 68719476736
kernel.shmmni = 4096
#kernel.sem = 256 32000 100 142
kernel.sem = 256 96000 100 1024
fs.file-max = 6553600
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
"/etc/sysctl.conf" 70L, 2012C written

root@hostname:~#sysctl -p
net.ipv4.tcp_max_syn_backlog = 8192
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.ip_forward = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.conf.all.rp_filter = 1
kernel.sysrq = 0
kernel.core_uses_pid = 1
net.ipv4.tcp_syncookies = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.core_pattern = /var/core/core_%e_%p
kernel.shmall = 4294967296
kernel.shmmax = 68719476736
kernel.shmmni = 4096
kernel.sem = 256 96000 100 1024
fs.file-max = 6553600
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 4194304
kernel.msgmni = 2878
root@hostname:~#exit
logout
hostname:elcaro:$ dbi si

SQL*Plus: Release 11.2.0.1.0 Production on Thu Aug 4 23:33:13 2011

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup nomount;
ORACLE instance started.

Total System Global Area 4275781632 bytes
Fixed Size                  2220200 bytes
Variable Size             905973592 bytes
Database Buffers         3355443200 bytes
Redo Buffers               12144640 bytes
SQL> exit

 

 關(guān)于free 和　/proc/sys/vm/drop_caches ,可參考：

http://wenku.baidu.com/view/c203c27a31b765ce05081410.html

http://blog.csdn.net/turkeyzhou/article/details/6426738