PRM-SCAN extract datafile from corrupted asm disk group
let ‘s go !
asmcmd
lsdsk
lsdg
let corrupt the asm disk header by manual
dd if=/dev/zero of=/dev/vdb1 bs=1024k count=10 conv=notrunc
this will write zero to asm header 10M
SQL> alter diskgroup data mount;
alter diskgroup data mount
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15017: diskgroup “DATA” cannot be mounted
ORA-15040: diskgroup is incomplete
fail to mount the corrupted asm disk group
ok
use PRMSCAN to scan the failed asm diskgroup’s disk
this only require read-only permission
it will take long time to scan , up to the disk size
java -jar PRMScan.jar –outputsh o1.sh
this command will output lots of dd command , help you extract datafiles blocks and merge them into datafiles
let see it
some datafiles may need to be ignored , find out your datafiles !!
execute the shell will generate datafiles under your current directory !
if you have multiple db’s system01.dbf store on same diskgroup , you may need to distinguish them by yourself, or you can call parnassusData service
let’s extract data from the datafile using prm !!
prm scan can work on
1. corrupted asm diskgroup ,failed to mount
2. corrupted / formatted filesystem
3. deleted datafile from asm diskgroup
4. deleted datafile from filesystem
filesystem(ntfs,ext 2/3/4,xfs whatever filesystem type)
we provide prm scan as a product (bundle with prm) or a service .
contact us service@parnassusdata.com !!
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