如果logfile被删除

eagle_fan

原帖由 Yong Huang 于 2010-4-9 04:44 发表


I was referring to the fact that on UNIX/Linux, when you use LGWR to transport redo, "lgwr进程每时每刻都获得所有logfile的文件句柄". Because the logfiles are all held open, deleting their filesystem entries is not a problem. You can simply restore the files from the pseudo files on /proc.

> 如果是普通的文件的话，可以通过metalink note "Retrieve deleted files on Unix / Linux using File Descriptors "恢复
> 不过我们使用的是veritas qio文件，目前没有找到办法

Isn't it the same? That is, copy the pseudo file from /proc to where it should be, e.g. /oracle/SCRATCH/data03/XFAN/redo/.redo1.log::cdev:vxfs: ?

Yong Huang

It's different. It's character file and you can't cat or dd it.

For example:

pfiles 18161
272: S_IFCHR mode:0660 dev:53,101003 ino:14 uid:32000 gid:101 rdev:58,355
      O_RDWR|O_DSYNC|O_LARGEFILE FD_CLOEXEC
      advisory write lock set by process 18153
      /oracle/MOT/data01/.MOT_temp01b.dbf::cdev:vxfs:
273: S_IFREG mode:0660 dev:53,101003 ino:1345 uid:32000 gid:101 size:524296192
      O_RDWR|O_DSYNC|O_LARGEFILE FD_CLOEXEC
      advisory write lock set by process 18153
      /oracle/MOT/data01/MOT_temp02a.dbf

cd /proc/18161/fd
ls -al 272
c--------- 1 oracle dba 58, 355 Apr  9 09:52 272
ls -al 273
-rw-rw---- 1 oracle dba 524296192 Apr  9 11:48 273

I opened a veritas case and the support told me it was impossible to recover the deleted qio file.

But I don't believe it

[ 本帖最后由 eagle_fan 于 2010-4-13 18:20 编辑 ]