EMC ! EMC ! , Knowing about EMC Data Domain Filesystem

Hey all now a days there's lot of buzz about EMC i see lot of my customers switching to EMC , I have already started working on Data Domain and VNX i just wanted to share some of my experience and understanding.

The Data Domain file system resides on ddvar directory and it is like a root directory.  It can be shared as NFS/CIFS share but one cannot rename or delete it because it holds the operating environment binaries and configuration.

And you will have a Data Directory followed by sub-directory called collection 1 which will be like /data/col1 and by default there is only one collection i.e., collection #1 under col1 you will have folders or MTrees , the default is called backup where all your backups will be stored however you can create more Mtrees under /col1 and each Mtree can be managed individually it has its own permissions and quota settings ( If needed to restrict ). The maximum number of Mtrees is 100. Any Mtree can be mounted as NFS shares or Mapped as CIFS shares.

Also Quotas can be set on Mtrees where we have two types Hard and Soft quotas, Hard Quotas will restrict the users from writing any data once the limit is reached and Soft quota will send the warnings and alerts.

Each MTree can be individually managed with its own policies and permissions.  The max number of MTrees is 100, however after 14 there is a performance degradation in environments where there is a lot of read/write streams to each MTree.  Best practice dictates that you keep MTrees to 14 and to aggregate operations to one MTree where possible.  You can mount MTrees like any other CIFS/NFS share, however it is not recommended to mix protocol type.  VTL and DDBoost clients create their own MTree, as well.

Netapp Snap Restore at Volume Level

Today i have performed snap restore on few production volume reverting to the snapshot of dated 20-May-2014. Here i share the procedure with you all.

I have restored snapshot of all 12 prod volumes. Please be noted snap restore can be performed both at VOLUME LEVEL and FILE LEVEL.

Volume level is to revert back the volume to whatever the date you want based on the snapshot in my case my latest snapshot is on 20-May-2014 so I’m  reverting back to it

File level is to restore a single file , we have to mention  type   –t  (vol | file )  while restore.

Im doing at volume level....

Example:-


snap restore -t vol  <vol-name>

snap restore -t vol snap_prodcli_prod_fb

WARNING! This will revert the volume to a previous snapshot.

All modifications to the volume after the snapshot will be

irrevocably lost.

Volume snap_prodcli_prod_fb will be made restricted briefly before coming back online.

Are you sure you want to do this? yes

The following snapshots are available for volume snap_prodcli_prod_fb:

     date            name
------------    ---------

May 20 17:12    20140520_bkup  -->  I am Reverting to this Snapshot

May 12 05:50    20140512_bkup

May 09 18:35    filervltp1(0151751825)_snap_prodcli_prod_fb.1

May 09 17:55    20140509_coldbkup

Apr 10 15:41    20140410_coldbkup

Which snapshot would you like to revert volumesnap_prodcli_prod_fb to?  20140520_bkup   ( Here mention the snapshot name to which you want to revert )

You have selected snap_prodcli_prod_fb,  snapshot 20140520_bkup

Proceed with revert? yes

Thu May 22 10:58:39 SGT [filervltp1:wafl.snaprestore.revert:notice]: Reverting volume snap_prodcli_prod_fb to a previous snapshot.

Volume snap_prodcli_prod_fb : revert successful.

It’s been successful :)

Restoring Oracle Archive Logs using RMAN from Tapes

I got a request from my client asking to restore Archivelogs of  particular sequence. let me brief you all our Oracle using ASM and our backup software is Netbackup.

Generally you can restore archive logs from the OS backup by starting the BAR utility from Netbackup MASTER SERVER but in my case these are ASM files so it cannot be seen from the OS backups so have to invoke the BAR from the CLIENT but i faced an error when i tried to list the files in BAR " Library Binaries Error" something strange so i have opened a case with Netbackup but Netbackup denied support as my NBU version is 6.5.4 which is EOS ( End of Support ) already , So now i have only one way to restore is through RMAN , After some struggle with google  i was able to build a script to restore my archivelogs



Note:- I am going to restore the archivelogs to an alternate location on the same server may be /tmp in my case but please check if you have enough space in the particular directory before proceeding with the restore and also get the LOGSEQUENCE  from your DBA

Login to the Host then switch to oracle

prdbclient:~ #  su - oracle

prdbclient: : oracle:>

Now go to the instance for which you want to restore Archivelogs

 prdbclient: : oracle:> prdb1



 prdbclient:prdb1: oracle:>



Once you are logged in to the instance now go to the RECOVERY MANAGER ( RMAN )   PROMPT ( Check with your DBA for the home directory of Oracle to be set )

/OraBase/V10010/bin -->  Is my Oracle Home directory

prdb1/prdb1 -->  Oracle Userid and Password ( You can get userID and Password from you RMAN SCRIPT )

Now type in as below to go to RMAN prompt of instance prdb1

prdbclient:prdb1: oracle:> /OraBase/V10010/bin/rman target / catalog prdb1/prdb1@rman

Once done run the restoration script

RMAN>

 run {

set archivelog destination to '/tmp/PRDB1_Archlogs';

ALLOCATE CHANNEL t1 TYPE 'SBT_TAPE';

SEND 'NB_ORA_CLIENT=prdbclient, NB_ORA_SERV=masbak, NB_ORA_POLICY=prdbclient_prdb1_archlog_daily';

restore archivelog from logseq=443196 until logseq=433299;

RELEASE CHANNEL t1;

}


Monitor the Restoration Job from the Netbackup Console

 Once completed successfully let the DBA do his job :)