ASM or not?

Similar Questions

• GoldenGate extract with ASM does not

  Hi experts,

  I have config GoldenGate with ASM and extract process works do not.

  Source:

  GoldenGate version: 12.1.2.1.0

  Oracle version: 11.2.0.4

  I have config ASM is standardalone

  Settings file:

  extract crosshead

  SETENV ("ORACLE_SID = orcl")

  SETENV ("ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1")

  exttrail ./dirdat/aa

  gguser@ORCL username, password gguser

  tranlogoptions asmuser sys@ASM, password ASMPASSWORD

  table testgg.*.

  Report file:

  ***********************************************************************

  * In the course of a run with the following parameters *.

  ***********************************************************************

  2015-04-03 10:43:20 identifies the character set of INFO-OGG-03059 in operating system

  d as US-ASCII.

  2015-04-03 10:43:20 parameter INFO OGG-02695 ANSI SQL syntax is used for pa

  rameter analysis.

  extract crosshead

  SETENV ("ORACLE_SID = orcl")

  2015-04-03 10:43:20 INFO OGG-02095 successfully set environment variable "O".

  RACLE_SID = orcl ".

  SETENV ("ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1")

  2015-04-03 10:43:20 INFO OGG-02095 successfully set environment variable "O".

  RACLE_HOME=/U01/app/Oracle/product/11.2.0/dbhome_1 ".

  exttrail ./dirdat/aa

  gguser@ORCL username, password *.

  Thank you

  T N

  Hello

  In the present can running in the extraction process.

  I reinstall GoldenGate. This success.

  I assumed install file is not complete.

  Thank you

  T N

• ASM does not come after the operating system upgrade

  Hi all

  I am very new to Oracle, I had a test environment perfectly work on a virtual machine running RHEL5.8 and Oracle 11.2.0.4 on env single node.

  I then did an upgrade of the OS (with option of linux upgradeany) of RHEL5.8 to RHEL6.4. Update went well and on the side of the BONE, everything worked as expected.

  However, the ASM has no start (check with ps - ef | grep smon & pmon) and both returned nothing.

  Please suggest any difficulty which could help solve this problem. I'm willing to try any suggestions of command since it is a test area.

  Thank you

  Hello

  You must re-bind all the shared library. Take a look at this note: how to create a link to The Oracle Grid Infrastructure independent (reboot) Installation or Oracle Grid Infrastructure Installation/RAC of Cluster (11.2 or 12 c). (Doc ID 1536057.1)

  Kind regards.

• Oracle ASM or not?

  Hi all!

  I just read document VMware, titled "Oracle Database on VMware best practices Guide"... It is a very good document, but I wonder why it only addresses configuration using Oracle ASM database.

  I understand that for better flow, it would be preferable to use ASM...

  (I also understant as raw device mapping is the best configuration for performance - BUT I certainly would not recommend using RDM for the complexity of management he added..).

  It seems simple to implement ASM here because of responsibilities (sysadmins vs s/n).

  So my question is:

  1 - at - it someone * NOT * using DSO for their Oracle on VMware database successfully?

  What I mean by that, no instance ASM, data files on VMFS file system...

  2 - does anyone actually measured the performance difference (between ASM and DO NOT ASM use)?

  3. I know that it is recommended as a best practice (for the best flow) to separate online redo logs and data files - but not really NOT bad to do?

  In other words, how is harm to merge the logs with data files.

  All thoughts/references are welcome...

  Jocelyn

  See https://community.oracle.com/message/12273470#12273470

  1 & 2: ASM or non - difference performance wise is not that big

  2 - reasons to log files & data separate are for caching of the locations (i.e. EMC Fast Cache) & recovery.

• urgent asm does not start with ora 1031. !!!

  Hi guys,.
  Stuck with a problem who are unsure how to proceed... cluster services doesnot comeup... tried to watch using crsctl start - n node cluster gives me error... below I'm missing something here... Can someone help me please on this...
  
  [node + ASM1:root] crsctl start - n node of cluster
  CRS-2672: attempt to start 'ora.asm' on 'node '.
  ORA-01031: insufficient privileges
  CRS-5017: the action "ora.asm start" resource has met the following error:
  ORA-01031: insufficient privileges
  . For details, refer to "(:CLSN00107:))" "in ' / u01/app/11.2.0.3/grid/log/node/agent/ohasd/oraagent_grid/oraagent_grid.log '.
  CRS-2674: beginning of 'ora.asm', the 'node' failed
  CRS-2679: attempt to clean the 'ora.asm' on 'node '.
  ORA-01031: insufficient privileges
  CRS-2681: clean 'ora.asm' on 'node' successful
  CRS-4705: beginning of the Clusterware failed on the node.
  CRS-4000: Start command has failed, or completed with errors.
  
  
  crsctl check crs shows me the following...
  
  CRS-4638: Oracle high availability Services is online
  CRS-4535: cannot communicate with Cluster Ready Services
  CRS-4529: Cluster Synchronization Services is online
  CRS-4534: can not communicate with the event Manager
  
  tried from asm manually... but not sufficient privileges said...
  
  
  [node: + ASM1:grid] echo $ORACLE_HOME
  /U01/app/11.2.0.3/grid
  [node: + ASM1:grid] echo $ORACLE_SID
  + ASM1
  
  
  
  [node: + ASM1:grid] sqlplus "virtue sysdba".
  
  SQL * more: Production of liberation 11.2.0.3.0 sam 8 15:21:21 dec 2012
  
  Copyright (c) 1982, 2011, Oracle. All rights reserved.
  
  Connect to an instance is idle.
  
  SQL > startup
  ORA-01031: insufficient privileges
  
  Grid has the following privileges
  
  [node: + ASM1:grid] id
  UID = 501 (Grid) gid = 501 (oinstall) groups = 501 (oinstall), 502 (dba), 504 (asmadmin), 506 (asmdba), 507 (asmoper)
  
  ID [node: ipdexdev1:oracle]
  UID = 502 (Oracle) gid = 501 (oinstall) groups = 10 (wheel), 501 (oinstall), 502 (dba), 506 (asmdba)
  
  The other node works very well... against the privileges that they are the same on the other node too...

  sys / ACE sysasm

  then start

• ASM does not work after kernel upgrade

  We have recently updated (only updates security - yum update of security) our RHEL 5.6 (Tikanga) + Oracle 11G and ASM.
  (1) the first thing we saw him after that restart was this error:
  
  [+[Oracle@hostname ~] $ sqlplus +.
  
  SQL * more: version 11.1.0.7.0 - Production Wed Jul 27 12:57:36 2011
  
  Copyright (c) 1982, 2008, Oracle.  All rights reserved.
  
  Enter the user name: user name
  Enter the password:
  ERROR:
  ORA-01034: ORACLE not available
  ORA-27101: shared memory realm does not exist
  Linux-x86_64 error: 2: no such file or directory
  Process ID: 0
  Session IDs: serial number 0: 0
  
  
  I tried to start it but to no avail:
  [+[Oracle@hostname ~] $ sqlplus / as sysdba.
  
  SQL * more: version 11.1.0.7.0 - Production Wed Jul 27 15:47:06 2011
  
  Copyright (c) 1982, 2008, Oracle.  All rights reserved.
  
  Connect to an instance is idle.
  
  SQL > Select * from v$ instance;
  Select * from v$ instance
  *+
  ERROR on line 1:
  ORA-01034: ORACLE not available
  Process ID: 0
  Session IDs: serial number 0: 0
  
  SQL > the judgment
  ORACLE instance stops.
  SQL > startup nomount
  ORA-01078: failure in the treatment of system settings
  ORA-01565: error in the identification of file ' DG1/ourdb/ourdb.ora'+
  ORA-17503: ksfdopn:2 could not open the file DG1/ourdb/ourdb.ora+
  ORA-15077: could not locate instance ASM serving a required diskgroup
  SQL > alter database mounting
  + 2 +
  SQL > alter the editing of the database;
  change the database editing
  *+
  ERROR on line 1:
  ORA-01034: ORACLE not available
  Process ID: 0
  Session IDs: serial number 0: 0
  
  Then we checked ASM:
  
  [+[root@hostname ~] # /etc/init.d/oracleasm listdisks +.
  [+[root@hostname ~] #+.
  
  
  that didn't work because the "oracleasm" kernel module has not been loaded.
  
  [+[root@hostname ~] # lsmod | grep oracleasm +.
  [+[root@hostname ~] #+.
  
  This is most likely due to the recent update of the kernel
  Of
  + 2.6.18 - 238.5.1.el5 +.
  TO
  + 2.6.18 - 274.el5 +.
  
  I think that modules of Oracle for some particular kernel versions and our version is not supported:
  
  [+[root@hostname ~] # oracleasm update-driver +.
  Kernel: 2.6.18 - 274.el5 x86_64
  Driver name: oracleasm - 2.6.18 - 274.el5
  There is no driver for kernel 2.6.18 - 274.el5
  [+[root@hostname ~] #+.
  
  Y at - it a script that can generate for our version of the kernel module (something similar like vmware offer)? Or put the oracleasm pilot is the only way?
  
  We have workaround copy old kernel module to new kernel directory:
  
  [+[root@hostname ~] #cp /lib/modules/2.6.18-238.5.1.el5/kernel/drivers/addon/oracleasm/oracleasm.ko /lib/modules/2.6.18-274.el5/kernel/drivers/addon/oracleasm/+
  [+[root@hostname ~] #+.
  
  and charge of this module in memory:
  
  [+[root@hostname ~] # insmod /lib/modules/2.6.18-274.el5/kernel/drivers/addon/oracleasm/oracleasm.ko+
  [+[root@hostname ~] # lsmod | grep oracleasm +.
  oracleasm 84136 0
  [+[root@hostname ~] #+.
  
  and then the ASM began to display the disks:
  
  [+[root@hostname ~] # /etc/init.d/oracleasm status.
  Check if the DSO is responsible: Yes
  Check if/dev/oracleasm is mounted: no
  [+[root@hostname ~] # /etc/init.d/oracleasm stop +.
  + Deletion of Oracle ASMLib discs: [OK] +.
  + Stop the Oracle ASMLib driver: [FAILURE] +.
  [+[root@hostname ~] # /etc/init.d/oracleasm start +.
  + The Oracle ASMLib driver initialization: [OK] +.
  + Analysis of the system for Oracle ASMLib discs: [OK] +.
  [+[root@hostname ~] # /etc/init.d/oracleasm listdisks +.
  ASM01
  ASM02
  [+[root@hostname ~] #+.
  
  All this is perfect until you restart. How do I load this module oracleasm automatically?
  
  
  (2) then we tried to boot from the previous version of the kernel "2.6.18 - 238.5.1.el5. ASM works very well here and the 'oracleasm' module is loaded automatically after reboot.
  However we are still facing in the original question in the beginning:
  
  [+[Oracle@hostname ~] $ sqlplus +.
  
  SQL * more: version 11.1.0.7.0 - Production Wed Jul 27 12:57:36 2011
  
  Copyright (c) 1982, 2008, Oracle.  All rights reserved.
  
  Enter the user name: user name
  Enter the password:
  ERROR:
  ORA-01034: ORACLE not available
  ORA-27101: shared memory realm does not exist
  Linux-x86_64 error: 2: no such file or directory
  Process ID: 0
  Session IDs: serial number 0: 0
  
  It was working fine before. How to fix with old or new core please?
  Thank you
  
  Published by: 872550 on July 28, 2011 01:39

  872550 wrote:
  We have recently updated (only updates security - yum update of security) our RHEL 5.6 (Tikanga) + Oracle 11G and ASM.

  It was working fine before. How to fix with old or new core please?
  Thank you

  Hello

  Try to download and install this oracleasm
  http://OSS.Oracle.com/projects/oracleasm/dist/files/rpms/RHEL5/AMD64/2.0.5/2.6.18-274.EL5/oracleasm-2.6.18-274.EL5-2.0.5-1.EL5.x86_64.rpm

  See you soon

• ASM is not getting up on a single node

  Dear all,
  
  I got two runing Oracle RAC from nodes in the last 2 years, now the system admin guy that they have updated the OS version.after filling when I tried to launch oracle RAC services. The ASM instance does not start on Node2.
  Node1 ASM and the instance database is runing fine. You can guide me please.
  
  
  [root@node2 ~] # uname - a
  Linux node2 2.6.18 - 238.12.1.el5xen #1 SMP Sat may 7 20:42:11 EDT 2011 ia64 ia64 GNU/Linux ia64
  [root@node2 ~] # rpm - qa - qf '% {NAME}-%{VERSION}-%{RELEASE}.%{ARCH}.rpm\n | grep asm
  oracleasm - 2.6.18 - 92.el5xen - 2.0.5 - 1.el5.ia64.rpm
  oracleasm-support - 2.1.2 - 1.el5.ia64.rpm
  oracleasmlib - 2.0.3 - 1.el5.ia64.rpm
  [root@node2 ~] #.
  
  I have same RPM ASM on node1 who is runing fine.
  
  ASM alerts log error is
  ORA-15183: error initializing the ASMLIB [driver or not installed the agent]
  ORA-15183: error initializing ASMLIB
  
  
  
  Thank you

  Hello

  Your asm package does not match with your OS kernel 2.6.18 - 238.12.1.el5xen

  Try to install the exact same version with kernel and try again

  or

  Compare/etc/sysconfig/oracleasm of two nodes

  See you soon

• ASM does not start after you restart the system.

  OS = Linux 5
  Grid = 11 GR 2
  
  I've successfully installed grid for a stand-alone server. However, after I restarted the server and commissioning upward the clusterware (crsctl start has), I got the following error message when you try to start ASM
  
  sqlplus / as sysasm
  SQL > startup
  ORA-27154: post/wait create failed
  ORA-27300: OS dependent operating system: semget failed with status: 28
  ORA-27301: OS error: no space is available on the device
  ORA-27302: an error occurred at: sskgpsemsper

  kernel semaphore seems insufficient, increase last kernel.sem value in /etc/sysctl.conf and try to run to the top of the DSO.

  REF the link to follow the steps below:

  http://blog.ronnyegner-consulting.de/2011/04/11/ora-27154-postwait-create-failed-ora-27301-OS-failure-message-no-space-left-on-device-when-starting-ASM-or-database-instance/

• Create the ASM disk groups instance is not found

  
  Hello

  I just started to learn Oracle, very inexperienced database in Oracle.

  I have a problem to create an ASM instance. My environment is SUSe Linux Enterprise 11 64-bit, I am creating an instance ASM 11.2.0

  1. when I create ASM instance, I couldn't find ASM disks, if an ASM Instance could not be created.

  2. when I search on the internet on the creation of the ASM disk, it seems that I need to connect to the instance ASM as ASMSYS, but I have not an ASM instance is runing so ASM DISK groups has not can be created.

  I feel that I'm at an impasse.

  Could someone help me?

  Thank you.

  You may need to configure the udev subsystem to set permissions of the device and configure the parameter diskstring ASM or install Linux ASMLib, that supports both and more.  In any case, you will need to provide more details and probably do some research to learn more about the basic concepts. To install Oracle ASM is not click and play.

• Disks / start transposition ASM

  Hi all

  Db1 size: 700 GB +.

  Size of DB2: 2.8 TB +.

  + ASM_DG_DATA is > for CRD files

  + ASM_DG_FRA is > for rman backups / archive files in logs/EXPDP...

  > > All recommended options?

  How many drives / starts, we can keep transposition ASM (for good e/s)?

  I suggest you consult the documentation:

  https://docs.Oracle.com/CD/E11882_01/server.112/e18951/asmprepare.htm#OSTMG11000

  You can find more useful 'Recommendations for the preparation of storage'.

  For example:

  A minimum of four (Oracle ASM disks) LUNS of equal size and performance is recommended for each disk group.

  Using Oracle ASM mirroring redundancy when using no hardware RAID, or when you need host-based volume management features.

  
  

  I suggest to keep in mind that ASM is not RAID. RAID uses a fixed allocation size and reflects the data at the level of the block device. ASM reflects files by using a size of distribution variable patterns of files, which gives an advantage of performance when writing to newspapers in recovery, for example.  You can combine ASM and RAID to increase performance and features, but what you choose depends on your budget and your requirements, which is anyone's guess.

  About disk groups ASM how you create, my answer is that there is no performance gain unless you can redirect i/o to separate physical disks. At a minimum, it is best to separate the DATA and FRA, but otherwise, if all the data is on the same storage device and the path of I/O, additional disk groups will not give you improve performance.

  Unless you know exactly how you size your drive includes and how you want to limit the occupation of space by a specific disk group, several groups of disks have the potential for management fees and complications, for example when executing space in one group, while having "too much" in another.

• Is have RAID (1 + 0) so that Failgroups for all ASM ASM starts is a well-known best practice?

  Dear Experts,

  Is have RAID (1 + 0) so that Failgroups for all ASM ASM starts is a well-known best practice?

  Having both is the best practice

  • RAID (1 + 0)
  • ASM Failgroups for all ASM starts

  Thank you

  IVW

  You can create groups of ASM disks with normal or high redundancy or specify external redundancy. It depends on your reliability requirements and storage performance. Remember that ASM is not RAID and redundancy is the base file. ASM uses alternating devices. Oracle is generally recommended to have redundancy of storage. If you have RAID redundancy at the level of hardware controller or storage, Oracle recommends to configure ASM disks with external redundancy groups. Redundancy of the DSO is only between groups of disk failure and by default, each device's own failure group. Of course, you always want to make sure that you do not rely on redundancy of data between logical devices or partitions residing on a single physical unit. Compared to external RAID redundancy redundancy ASM using will give the DBA more control and transparency on the setting of the underlying.

• Backup the ASM itsself

  Hello

  I have just setup an ASM instance.

  Referring to my Docs as DBA2 training I get this message:
  There is a process of ARC redolog backup information, known as an instance of database.

  However, the manual also says "there is that no BUFFER in SGA and ASM does not use online redo logs. LGWR writes the information to an ASM Diskgroup".

  Now I'm a little confused:

  Does make sense to put the instance ASM itself in archivelog one mode run backups via RMAN?

  Or should I use md_backup instead?

  Concerning

  Christian

  11 GR 2

  If there ANY configuration changes - vote data disk is automatically saved in the OCR.

  BACKUP OF THE OCR IS AUTO-

  one) oracle Clusterware (CRSD) automatically creates backups of OCR every 4 hours.

  (b) a backup is created for each full day.

  (c) a backup is created at the end of each week.

  (d) oracle database retains the last three copies of OCR.

  But you can also make manual backups

  Example:

  To display the backup, type the commands: ocrconfig - showbackup

  Perform a manual backup: ocrconfig - manualbackup

  Logical backup: #ocrconfig-/home/oracle/ocr.backup export

  Backup only manual display: ocrconfig - showbackup manual

  The RSC (Oracle registry Local) location: #ocrcheck - local

  Logical backup of OLR: ocrconfig-local - export /... /OLR. Backup

• ASM files using RMAN backupset backup system migration

  my script to backup daily as below

  backup in the format of compressed backupset "$BACKUP_DIR/db_%U" database

  backup current controlfile "$BACKUP_DIR/Cont_%U" format

  backup as backupset archivelog Tablet format all '$BACKUP_DIR/arch_%U ';

  It is possible to migrate the database ASM uses above backup backupset RMAN?

  because I restore the database is restored, the problem is when he try to recover it, unable to understand the archivelog and redlog files.

  Hello

  in fact, after I moved the pieces to another server and called with RMAN (including the archivelog files)

  1. When you have moved to another server, then at this stage - my hypothesis, you have restored the controlfile to fileystem and mounted

  2. as you said moved to another server, the parts are on file system or (ASM location - still the second server can see)? If your answer is no, when you catalog now, controfile must save it with the file system path but not ASM

  Note - If you're still see ASM path then. the migration of the ASM to no - asm (the steps are not correct) logically you went wrong and implementation/execution thrown.

  3. provide the plan and execution - what you did (while we can fix). To be honest, while on the move DB to non - asm, why you need first to recovery? Tell me about your backup procedure itself is gone bad.

  To be honest, you try to database host of ASM no - asm as backup in function (but no real process of moving).  Therefore, in spite of the use of rman backup in dual function duplication... you have implemented in the wrong approach.

  This is the reason why I have provided the link and examples to understand.

  Hope you understand now.

  -Pavan Kumar N

• How to set permissions for drives avoid the ORA-15063 start-up ASM?

  Hello

  When I try to reboot the DSO after a reboot of the server, I get

  ERROR: diskgroup DATA was not mounted

  ORA-15032: not all changes made

  ORA-15017: diskgroup 'DATA' cannot be mounted

  ORA-15063: ASM discovered an insufficient number of drives for diskgroup "DATA".

  It seems the permission of disks have changed after the reboot. I guess the spfile is inside the DATA diskgroup because it can not even start ASM. When I create a file with values asm_diskgroup and asm_diskstring pfile and 777 on the drive, I managed to start the ASM.

  * .asm_diskgroups = "INDX", "DATA".

  * .asm_diskstring = "/ dev / *'"

  $ oracleasm querydisk p - DATA

  Disk 'DATA' is a valid ASM disk

  / dev/sdb4: LABEL = 'DATA' TYPE = 'oracleasm.

  $ ls-la/dev/sdb *.

  ...

  BRW - rw - 1 root disk 8, 19, 29 mai 10:42 / dev/sdb3 it

  brwxrwxrwx 1 root disk 8, 20, 29 mai 15:17 / dev/sdb4

  ...

  And when I read the documentation I see this ' that the owner of the ORACLE binary file has permissions to read/write on the discs"(so do not run required) but the problem is that this test server should have the same parameters as in production. And the production server has brw - r - for the corresponding disk. So my questions are

  Can it be handled somehow in a different way? How can this have been reached production without the same settings I put in test? Is there an other way around for me in test to achieve?

  The network user (who owns the infrastructue grid) belongs to the same group of test and production. Test and production have ASM version 11.2.0.3, but the different operating system.

  production: 2.6.18 - 274.12.1.el5

  test: 2.6.32 - 504.16.2.el6.x86_64

  As this is my first ASM/grid infrastructure, I don't even know where to begin this review except the support.oracle.com search but I've not found anything except the Action for the error code (which is perhaps the only way around it)

  Any help is appreciated

  Thank you

  / Jenny

  Remember that the permissions of the device must be configured so that the owner of the Oracle database or the process has full access to the appropriate device files. It is not enough to only give ASM full authorization for devices files. ASM provides management for volume, but the database has direct access to device files and ASM does not interfere with inputs and outputs. You can set up groups and owner accordingly. If you have a different owner for ASM, you must assign appropriate groups to give full access ASM configuring oracleasm.

• Redundancy of the Normal ASM - three stores, three groups of failure

  Hello

  I have a question about groups of failure in ASM. I have an ASM diskgroup with normal redundancy and records of three different preparations. Each storage disks are in separate groups of failure (see screen below). I know what ASM allocates to a point as it allocates a copy of copy and the primary mirror and mirror copy is placed on a different disk that is part of a group of different failure. And it is understood for the configuration with two storage (or controllers) and two different groups of failure. But what with configuration where are three storages and failure groups? My question is: If I failed three groups if new extensions are allocated are mirrored are placed on the other two discs are it is a part of a group of different failure? Or maybe this kind of configuration (with three groups of normal redundancy ASM failure) is not supported?

  

  I know what ASM allocates to a point as it allocates a copy of copy and the primary mirror and mirror copy is placed on a different disk that is part of a group of different failure. And it is understood for the configuration with two storage (or controllers) and two different groups of failure. But what with configuration where are three storages and failure groups? My question is: if I have three groups of failure, if new extensions are allocated are mirrored are placed on the other two discs are it is a part of a group of different failure? Or maybe this kind of configuration (with three groups of normal redundancy ASM failure) is not supported?

  No matter how much you failgroup. Normal redundancy requires at least 2 Failgroup.

  Oracle will allocate primary measure in a failgroup and place the mirror of the scopes in an another failgroup.

  The order does not matter since you always have a copy in a different failgroup.

  See example below (d = data extended)

  FG1 |   FG2 | FG3

  ========|===============|=========
  

  d1      |   d1_copy:

  |   d2          | d2_copy

  d3_copy |               | d3

  When you create a Diskgroup without specifying the failgroup, Oracle will automatically create a failgroup to each diskgroup. So, if you create a normal with normal redundancy Diskgroup and ASMDISK 10, ASM will create 10 failgroups.

  You have 3 warehouses and 3 Failgroup

  If you loss storage (h/f) ASM will tolerate because you measure mirror in any other failgroup (h, l, square).

  If you loss both storage (h/f) or two different storage disk/controller at the same time ASM will not tolerate. (Need to restore a backup database)

  Your point of failure: you must make sure that the two storages/controllers/disks will still be available.

  If your concern is: can I have a situation where two storage can do fail (or cut) at the same time. Then, you need high redundancy, because this configuration will tolerate you two storages loss (h/f) at the same time and Diskgroup will remain active.