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如果oracle进程已经关闭，无法再通过利用ora_进程跟踪文件句柄进行恢复，那么还有无方法来对误删除的文件进行恢复呢?下面介绍一下用第三方软件进行恢复--首先确保已经安装了e2fsprogs包[root@ora10g ext3grep-0.10.2]# rpm -qa | grep e2fsprogse2fsprogs-1.39-20.el5e2fsprogs-devel-1.39-20.el5e2fsprogs-libs-1.39-20.el5--软件下载：http://ext3grep.googlecode.com/files/ext3grep-0.10.2.tar.gz--用Xshell复制到/opt目录下后编译安装[root@ora10g ~]# cd /opt/[root@ora10g opt]# lltotal 500drwxr-xr-x 3 1000 1000 4096 Aug 26 09:09 ext3grep-0.10.2-rw-r--r-- 1 root root 236364 Aug 26 09:08 ext3grep-0.10.2.tar.gzdrwxr-xr-x 3 root root 4096 Aug 22 16:44 ORCLfmapdrwxrwxr-x 8 oracle oinstall 4096 Aug 25 11:39 rlwrap-0.37-rw-r--r-- 1 root root 251438 Aug 25 11:37 rlwrap-0.37.tar.gz[root@ora10g opt]# cd ext3grep-0.10.2[root@ora10g ext3grep-0.10.2]# ./configure&&make&&make install编译过程略……--查看软件命令使用方法[root@ora10g ext3grep-0.10.2]# ext3grep --helpRunning ext3grep version 0.10.2Usage: ext3grep [options] [--] device-fileOptions:--version, -[vV] Print version and exit successfully.--help, Print this help and exit successfully.--superblock Print contents of superblock in addition to the rest.If no action is specified then this option is implied.--print Print content of block or inode, if any.--ls Print directories with only one line per entry.This option is often needed to turn on filtering.--accept filen Accept 'filen' as a legal filename. Can be used multi-ple times. If you change any --accept you must removeBOTH stage* files!--accept-all Simply accept everything as filename.--journal Show content of journal.--show-path-inodes Show the inode of each directory component in paths.Filters:--group grp Only process group 'grp'.--directory Only process directory inodes.--after dtime Only entries deleted on or after 'dtime'.--before dtime Only entries deleted before 'dtime'.--deleted Only show/process deleted entries.--allocated Only show/process allocated inodes/blocks.--unallocated Only show/process unallocated inodes/blocks.--reallocated Do not suppress entries with reallocated inodes.Inodes are considered 'reallocated' if the entryis deleted but the inode is allocated, but also whenthe file type in the dir entry and the inode aredifferent.--zeroed-inodes Do not suppress entries with zeroed inodes. Linkedentries are always shown, regardless of this option.--depth depth Process directories recursively up till a depthof 'depth'.Actions:--inode-to-block ino Print the block that contains inode 'ino'.--inode ino Show info on inode 'ino'.If --ls is used and the inode is a directory, thenthe filters apply to the entries of the directory.If you do not use --ls then --print is implied.--block blk Show info on block 'blk'.If --ls is used and the block is the first blockof a directory, then the filters apply to entriesof the directory.If you do not use --ls then --print is implied.--histogram=[atime|ctime|mtime|dtime|group]Generate a histogram based on the given specs.Using atime, ctime or mtime will change themeaning of --after and --before to those times.--journal-block jblk Show info on journal block 'jblk'.--journal-transaction seqShow info on transaction with sequence number 'seq'.--dump-names Write the path of files to stdout.This implies --ls but suppresses it's output.--search-start str Find blocks that start with the fixed string 'str'.--search str Find blocks that contain the fixed string 'str'.--search-inode blk Find inodes that refer to block 'blk'.--search-zeroed-inodes Return allocated inode table entries that are zeroed.--inode-dirblock-table dirPrint a table for directory path 'dir' of directoryblock numbers found and the inodes used for each file.--show-journal-inodes inoShow copies of inode 'ino' still in the journal.--restore-inode ino[@seqnr][,ino[@seqnr],...]Restore the file(s) with known inode number 'ino'.The restored files are created in ./RESTORED_FILES/with their inode number as extension (ie, inode.12345).If '@seqnr' is provided then (only) the journal entrywith that sequence number is used, otherwise the latestentry is used (if any). You can use that in the case aa file was overwritten or truncated, rather than deleted.--restore-file 'path' [--restore-file 'path' ...]Will restore file 'path'. 'path' is relative to theroot of the partition and does not start with a '/' (itmust be one of the paths returned by --dump-names).The restored directory, file or symbolic link iscreated in the current directory as 'RESTORED_FILES/path'.--restore-all As --restore-file but attempts to restore everything.The use of --after is highly recommended because theattempt to restore very old files will only result inthem being hard linked to a more recently deleted fileand as such polute the output.--show-hardlinks Show all inodes that are shared by two or more files.我们看到，还是有很多功能可以用的，这里我们只需用到3个参数：--ls --inode --restore-all--开始测试[root@ora10g ~]# mkdir /zlm[root@ora10g ~]# cd /zlm[root@ora10g zlm]# dd if=/dev/zero of=test1 bs=8096 count=1280012800+0 records in12800+0 records out103628800 bytes (104 MB) copied, 0.586624 seconds, 177 MB/s[root@ora10g zlm]# mkfs.ext3 test1mke2fs 1.39 (29-May-2006)test1 is not a block special device.Proceed anyway? (y,n) yFilesystem label=OS type: LinuxBlock size=1024 (log=0)Fragment size=1024 (log=0)25376 inodes, 101200 blocks5060 blocks (5.00%) reserved for the super userFirst data block=1Maximum filesystem blocks=6737100813 block groups8192 blocks per group, 8192 fragments per group1952 inodes per groupSuperblock backups stored on blocks:8193, 24577, 40961, 57345, 73729Writing inode tables: doneCreating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: doneThis filesystem will be automatically checked every 27 mounts or180 days, whichever comes first. Use tune2fs -c or -i to override.[root@ora10g zlm]# mkdir /oradata/ora10g -p[root@ora10g zlm]# mount -o loop /zlm/test1 /oradata/ora10g[root@ora10g zlm]# df -ThFilesystem Type Size Used Avail Use% Mounted on/dev/mapper/VolGroup00-LogVol00ext3 7.7G 5.6G 1.7G 77% //dev/sda1 ext3 99M 12M 82M 13% /boottmpfs tmpfs 506M 0 506M 0% /dev/shm/zlm/test1 ext3 96M 5.6M 86M 7% /oradata/ora10g--在挂载好的目录/oradata/ora10g中创建测试文件[root@ora10g ora10g]# touch redo01.log redo02.log redo03.log[root@ora10g ora10g]# lltotal 12drwx------ 2 root root 12288 Aug 27 13:59 lost+found-rw-r--r-- 1 root root 0 Aug 27 14:11 redo01.log-rw-r--r-- 1 root root 0 Aug 27 14:11 redo02.log-rw-r--r-- 1 root root 0 Aug 27 14:11 redo03.log[root@ora10g ora10g]# cat >> redo01.log << EOF> AB> EOF[root@ora10g ora10g]# cat >> redo02.log << EOF> CD> EOF[root@ora10g ora10g]# cat >> redo03.log << EOF> EF> EOF[root@ora10g ora10g]# lltotal 15drwx------ 2 root root 12288 Aug 27 13:59 lost+found-rw-r--r-- 1 root root 3 Aug 27 14:12 redo01.log-rw-r--r-- 1 root root 3 Aug 27 14:12 redo02.log-rw-r--r-- 1 root root 3 Aug 27 14:12 redo03.log--模拟误操作，删除/oradata/ora10g下所有文件[root@ora10g ora10g]# rm -rf *.*[root@ora10g ora10g]# lltotal 12drwx------ 2 root root 12288 Aug 27 13:59 lost+found[root@ora10g ora10g]# umount /zlm/test1umount: /oradata/ora10g: device is busyumount: /oradata/ora10g: device is busy[root@ora10g ora10g]# cd ~[root@ora10g ~]# umount /zlm/test1[root@ora10g ~]# df -ThFilesystem Type Size Used Avail Use% Mounted on/dev/mapper/VolGroup00-LogVol00ext3 7.7G 5.6G 1.7G 77% //dev/sda1 ext3 99M 12M 82M 13% /boottmpfs tmpfs 506M 0 506M 0% /dev/shm[root@ora10g ~]# ext3grep /zlm/test1 --ls --inode 2Running ext3grep version 0.10.2Number of groups: 13Loading group metadata... doneMinimum / maximum journal block: 519 / 4633Loading journal descriptors... sorting... doneThe oldest inode block that is still in the journal, appears to be from 1409119917 = Wed Aug 27 14:11:57 2014Number of descriptors in journal: 32; min / max sequence numbers: 2 / 10Inode is AllocatedFinding all blocks that might be directories.D: block containing directory start, d: block containing more directory entries.Each plus represents a directory start that references the same inode as a directory start that we found previously.Searching group 0: DD++Searching group 1:Searching group 2:Searching group 3:Searching group 4:Searching group 5:Searching group 6:Searching group 7:Searching group 8:Searching group 9:Searching group 10:Searching group 11:Searching group 12:Writing analysis so far to 'test1.ext3grep.stage1'. Delete that file if you want to do this stage again.Result of stage one:2 inodes are referenced by one or more directory blocks, 2 of those inodes are still allocated.1 inodes are referenced by more than one directory block, 1 of those inodes is still allocated.0 blocks contain an extended directory.Result of stage two:2 of those inodes could be resolved because they are still allocated.All directory inodes are accounted for!Writing analysis so far to 'test1.ext3grep.stage2'. Delete that file if you want to do this stage again.The first block of the directory is 505.Inode 2 is directory "".Directory block 505:.-- File type in dir_entry (r=regular file, d=directory, l=symlink)| .-- D: Deleted ; R: ReallocatedIndx Next | Inode | Deletion time Mode File name==========+==========+----------------data-from-inode------+-----------+=========0 1 d 2 drwxr-xr-x .1 2 d 2 drwxr-xr-x ..2 end d 11 drwx------ lost+found3 4 r 12 D 1409120047 Wed Aug 27 14:14:07 2014 rrw-r--r-- redo01.log4 5 r 13 D 1409120047 Wed Aug 27 14:14:07 2014 rrw-r--r-- redo02.log5 end r 14 D 1409120047 Wed Aug 27 14:14:07 2014 rrw-r--r-- redo03.log[root@ora10g ~]# lltotal 80-rw------- 1 root root 1618 Aug 22 11:19 anaconda-ks.cfgdrwxr-xr-x 2 root root 4096 Aug 22 12:58 Desktop-rw-r--r-- 1 root root 39989 Aug 22 11:19 install.log-rw-r--r-- 1 root root 4270 Aug 22 11:19 install.log.syslogdrwxr-xr-x 3 root root 4096 Aug 27 14:17 RESTORED_FILES-rw-r--r-- 1 root root 186 Aug 27 14:16 test1.ext3grep.stage1-rw-r--r-- 1 root root 133 Aug 27 14:16 test1.ext3grep.stage2test1.ext3grep.stage文件是执行命令后生成的，用来存放扫描信息--把扫描到的已删除文件恢复出来[root@ora10g ~]# ext3grep /zlm/test1 --restore-allRunning ext3grep version 0.10.2Number of groups: 13Minimum / maximum journal block: 519 / 4633Loading journal descriptors... sorting... doneThe oldest inode block that is still in the journal, appears to be from 1409119917 = Wed Aug 27 14:11:57 2014Number of descriptors in journal: 32; min / max sequence numbers: 2 / 10Writing output to directory RESTORED_FILES/Loading test1.ext3grep.stage2... doneRestoring redo01.logRestoring redo02.logRestoring redo03.log[root@ora10g ~]# ls -la RESTORED_FILES/total 28drwxr-xr-x 3 root root 4096 Aug 27 14:17 .drwxr-x--- 17 root root 4096 Aug 27 14:17 ..drwx------ 2 root root 4096 Aug 27 13:59 lost+found-rw-r--r-- 1 root root 3 Aug 27 14:12 redo01.log-rw-r--r-- 1 root root 3 Aug 27 14:12 redo02.log-rw-r--r-- 1 root root 3 Aug 27 14:12 redo03.log如果不想全部恢复，那么可以使用--resotre-file filename的方式来恢复，前提是你必须知道哪些是你需要恢复的文件--重新挂载磁盘并确认已经挂载成功[root@ora10g ~]# mount -o loop /zlm/test1 /oradata/ora10g[root@ora10g ~]# df -ThFilesystem Type Size Used Avail Use% Mounted on/dev/mapper/VolGroup00-LogVol00ext3 7.7G 5.6G 1.7G 77% //dev/sda1 ext3 99M 12M 82M 13% /boottmpfs tmpfs 506M 0 506M 0% /dev/shm/zlm/test1 ext3 96M 5.6M 86M 7% /oradata/ora10g--把丢失的文件从RESTORED_FILES中复制到源路径中[root@ora10g ~]# cp RESTORED_FILES/*.log /oradata/ora10g[root@ora10g ~]# cd /oradata/ora10g/[root@ora10g ora10g]# lltotal 15drwx------ 2 root root 12288 Aug 27 13:59 lost+found-rw-r--r-- 1 root root 3 Aug 27 14:21 redo01.log-rw-r--r-- 1 root root 3 Aug 27 14:21 redo02.log-rw-r--r-- 1 root root 3 Aug 27 14:21 redo03.log[root@ora10g ora10g]# cat redo01.log redo02.log redo03.logABCDEF[root@ora10g ora10g]#总结：可以看到，之前模拟在文件系统类型为ext3的/zlm/test1分区下rm -f误删除掉的数据文件都是可以恢复出来的，但前提是删除后没有写入操作，如同我们window中删除磁盘上的数据的原理一样，就算是误格式化了分区，只要没有写入过新的数据，还是能通过Easy Recovery之类的软件对数据进行恢复的。所以，当我们在Linux下误删文件，如果这个文件是挂载在某个分区下的，那么请立即卸载该分区，然后通过以上介绍的方法，对数据进行恢复。不过用这种方法恢复，需要你的数据库文件单独挂在在一个分区下，如果是直接用默认的放在/dev/mapper/VolGroup00-LogVol00，我测试过，是无法恢复出文件的，扫描会失败。在我的实验中，由于是测试环境，没有单独给数据文件分区，只是默认地安装，测试效果可能与实际环境有很大的区别，这里只是提供数据恢复的一种思路。先用创建了一个文件模拟一个磁盘，如：/zlm/test1并把它格式化成ext3grep的文件系统，ext3grep顾名思义，就是用在对ext3文件系统上进行数据文件恢复的工具，对于ext2、xfs等文件系统而言，它就爱莫能助了。当然，我相信还是能有其他方法或工具可以恢复数据的，这里就暂且不研究了。所以对于数据库系统而言，极力推荐把数据文件单独挂在在磁盘的分区中，而不是采用默认的磁盘分区，如果要使挂载永久生效，还要修改/etc/fstab文件，加入你要挂载的分区和目录信息。一旦发生误删除，而你的文件系统又恰巧是ext3，而数据库又意外地被关闭了。那么，ext3grep也许就是你最后的机会了！
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