VMWare causes journal aborted on ext3 file systems

VMWARE造成AS4 EXT3文件系统不能写入的例子:
 
Issue:
客户报告其服务器上安装AS4,在其上安装了VMWare,创建若干虚拟机,近段时间发现系统常常不能对某些分区进行写入操作.
 
Analysis:
从客户的message日志里 ,发现如下信息:
Apr 26 18:19:45 svr66 kernel: journal_get_undo_access: No memory for committed data
Apr 26 18:19:45 svr66 kernel: ext3_try_to_allocate_with_rsv: aborting transaction: Out of memory in __ext3_journal_get_undo_access
Apr 26 18:19:45 svr66 kernel: EXT3-fs error (device sdb1) in ext3_new_block: Out of memory
Apr 26 18:19:45 svr66 kernel: Aborting journal on device sdb1.
Apr 26 18:19:45 svr66 kernel: ext3_abort called.
Apr 26 18:19:45 svr66 kernel: EXT3-fs error (device sdb1): ext3_journal_start_sb: Detected aborted journal
Apr 26 18:19:45 svr66 kernel: Remounting filesystem read-only
Apr 26 18:19:45 svr66 kernel: EXT3-fs error (device sdb1) in ext3_ordered_writepage: Out of memory
Apr 26 18:19:45 svr66 kernel: EXT3-fs error (device sdb1) in ext3_new_block: Journal has aborted
由此可以看出,正是由于journal_get_undo_access: No memory for committed data,导致文件系统的日志信息不能被更新,进一步导致该文件系统被重新加载为"只读".联想到客户装有虚拟机,很可能是由于空闲内存不足造成.我们从VMWARE论坛里也能发现很多就此问题的讨论:
 
 
Solution:
修改/etc/sysctl.conf文件,加入:
 vm.min_free_kbytes = 10240
以便让系统释放出更多的可用内存 .修改后,客户测试了一段时间,再没有出现类似的问题.