Is RMAN backup directly to tape faster then to disk?

A coworker claims that performing a full backup to tape is twice as fast as opposed to disk. I cant find any documentation to support this claim. Any thoughts one way or another?

user10784896 wrote:
A coworker claims that performing a full backup to tape is twice as fast as opposed to disk. I cant find any documentation to support this claim. Any thoughts one way or another?Tell him to prove it. There are too many variables for someone to just make a claim like that without qualification. I'd say that - at best - he once clocked one paticular backup to tape as faster than one particular backup to disk.
That said, if the tape really were faster (even incrementally faster, not to mention "twice as fast") I'd say there was some serious mis-configuration in the disk backup - either in the specification or the layout of the disk system itself, because left to its on devices disk is inherently faster. Look at the published I/O specs of the disk vendor vs. the tape vendor.

Similar Messages

  • RMAN Backup Direct To Tape

    Hi,
    Can anyone out there give me assistance with setting up my database in order to backup it up directly to tape, via RMAN. We have the following setup:
    MS-Windows NT4.0 SP6.0a
    Oracle 8.1.7
    Veritas Backup Exec for Windows NT Ver7.3
    Tape drive is a Compaq DLT 40/80 (x2) with a TL891 mini library.
    Any help in this matter would be greatly appreciated.
    Many thanks
    Carl Scotson
    DBA - West Of Scotland Water

    If you don't already know the syntax for allocating a channel for a backup to tape here it is:
    ALLOCATE CHANNEL <channel_name> type 'sbt_tape';
    As for sending the backup to tape instead of the storage pool that will have to be setup on the media manager side. We do that for our backups with Tivoli, but it was setup to go directly to tape through the Tivoli media manager software.

  • Disadvantages of taking user manged backup directly on tape

    Hi,
    I have oracle 10.2.0.4 database on aix 5.3 Operating system.
    My all the datafiles,controlfiles,logfiles reside on /oradb filesystem.
    I have shut down the database & listner, & without copying all the database files into another file system.
    I have inform to backup team to take backup directly on tape by giving database file liocation /oradb.
    Please let me know the disadvantages of taking backup directly on tape by using user managed backup.
    Regards,

    All the list points are advantage of rman and are not available in user-managed so are the disadvantage of user-managed.
    ==> There are simpler backup and recovery commands.
    ==> It automatically manages the backup files without DBA intervention.
    ==> It automatically deletes unnecessary backup datafiles and archived redo log files both from disk and tape.
    ==> It provides you with detailed reporting of backup actions.
    ==> It provides considerable help in duplicating a database or creating a standby database.
    ==> It lets you test whether you can recover your database, without actually restoring data.
    ==> It lets you verify that available backups are usable for recovery.
    ==> It lets you make incremental backups, which isn’t possible by any other means of backup.
    ==> It lets you perform database duplication without backups by using the network-enabled database duplication feature, also known as active duplication.
    ==> It automatically detects corrupt data blocks during backups, with the corruption relevant information recorded in the V$DATABASE_BLOCK_CORRUPTION view.
    ==> When only a few data blocks are corrupted, you can recover at the data block level, instead of recovering an entire datafile.
    ==> You can take advantage of the unused block compression feature, wherein RMAN skips unused data blocks during a backup.
    ==> Only RMAN provides the ability to perform encrypted backups.
    ==> You can use RMAN with a variety of third-party storage systems.
    ==> You can use a powerful yet easy-to-use scripting language, which lets you write custom
    backup and recovery scripts quickly.
    Hope this may help u ..
    --neeraj                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

  • RMAN Backup Restore from tape

    Hello Gurus
    We have lvl0 RMAN database backup restored from tape but due to some reasons we could not apply recovery on it. On checking the information in controlfile, it identified only the system file and no other file. So, we recreated the controlfile and decided to recover using backup controlfile option (until cancel or until change or until time). However, to my surprise, when I listed the checkpointchange# and checkpoint_time columns of v$datafile_header, I found the difference in timestamps ranging 24 hrs -- which menat we had to apply 24 hrs of archiving to bring all dbfs to a consistent state (before it allowed us to open the db) -- so far so good, it worked that way.
    My question is that, while I trigger a lvl0 RMAN backup at say 4PM on 27th July and it finishes on 4PM on 28th July (as I am directly pushing around 1 TB data to tapes) -- what is the consistency timestamp of this backup. In other words, is this backup available for a restore of 4PM 27th July? Or is it available only for a restore of 4PM 28th July and later ...?
    Isn't it that RMAN works at block level and when I fire a backup it should give me all the dbf's of that timestamp..?
    Appreciate your inputs/comments.

    When taking a online backup with RMAN, the datafiles backup is always inconsistent because it needs the archived redo logs generated during the backup to be consistent: http://download.oracle.com/docs/cd/B19306_01/backup.102/b14192/intro005.htm#sthref70.
    A full online backup can only be used to restore the database to a point in time starting after backup end: if a backup starts at 4PM on 27th July and it finishes on 4PM on 28th July you can use it to restore the database to a point in time after 28-JUL 4PM.

  • RMAN backup compression and tape hardware compression

    Hello,
    Should tape backup compression be ON and RMAN compression OFF? What is the correct Oracle answer?
    Common knowledge says that if both hardware and software compression were allowed to be enabled at the same time the resulting file in some cases may actually be bigger than the original file. Hardware data compression is done by specialized chips and faster than software compression and increases the tape performance.
    I was reading somewhere some time ago that tape hardware will actually not attempt to compress data if the the data being processed cannot be compressed any further. But even if this is a hoax, wouldn't rman compression, at the cost of CPU, save I/O bandwidth?
    Thanks.
    Edited by: MaC on Dec 19, 2010 4:00 PM

    MaC wrote:
    I just located Oracle document ID 1018242.1, which outlines:
    Use either hardware or software compression, but NOT both. Using both will actually increase the size of the resulting file. The rule of thumb is: compression + compression = no_compression.
    Sounds kind a logic.I was actually going to post the same sentence but you did find it on your own :) . Another thing which is worth to mention that from 11.2, the RMAN backup compression is licensed with 4 options, High, Medium and Low . These all three options requires you to have Advanced Compression License to buy. There is another 4th option, Default which is free from license and the compression ratio of that lies in between of Medium and Low.
    HTH
    Aman....

  • Rman backup on TEVOLI tape

    Hi,
    Can anybody help me.TSM tape configured for linux RAC oracle database for rman backups.once i start backup its giving me followng error.can anybody provide me help
    Recovery Manager: Release 10.2.0.1.0 - Production on Fri Aug 18 20:49:36 2006
    Copyright (c) 1982, 2005, Oracle. All rights reserved.
    RMAN> connect target;
    connected to target database: IPO (DBID=1999149714)
    RMAN> BACKUP DATABASE PLUS ARCHIVELOG;
    Starting backup at 18-AUG-06
    current log archived
    using target database control file instead of recovery catalog
    RMAN-00571: ===========================================================
    RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
    RMAN-00571: ===========================================================
    RMAN-03002: failure of backup plus archivelog command at 08/18/2006 20:50:19
    ORA-19554: error allocating device, device type: SBT_TAPE, device name:
    ORA-27000: skgfqsbi: failed to initialize storage subsystem (SBT) layer
    Linux Error: 2534: Unknown system error
    Additional information: 7011
    ORA-19511: Error received from media manager layer, error text:
    SBT error = 7011, errno = 2534, sbtopen: system error
    RMAN>

    Possible solution is:
    The default path where TDPO looks at is '/usr/tivoli/tsm/client/api/bin64'
    even if the file DSM.SYS exists in another directory.
    The read permission of the file '/usr/tivoli/tsm/client/api/bin64/dsm.sys'
    was incorrect:
    -rw-r----- i.e. "OTHERS" which is Oracle isn't allowed to read the
    file /usr/tivoli/tsm/client/api/bin64/dsm.sys
    After changing permissions on /usr/tivoli/tsm/client/api/bin64/dsm.sys in order
    to allow oracle to use it then the backup works fine.
    $ chmod +r /usr/tivoli/tsm/client/api/bin64/dsm.sys
    The problem is on the TSM side. If the solution does not work you have to check TSM logs for further error messages.
    Werner

  • RMAN :  Backup to a tape.

    Hi every Body,
    I need please help on how to backup to a tape.
    Exactly how to configure the MML interface ?

    You can consider Oracle Secure Backup or a vendor from Oracle Backup Solutions Program.
    Check Configuring RMAN to Make Backups to a Media Manager for configuration of RMAN and the vendor specific documentation for the media management configuration.

  • RMAN BACKUP ERROR in TAPE

    Dear Friends,
    I am taking a RMAN BACKUP of ORACLE 9i with AIX4.3 with TAPE DRIVE
    When i execute the script
    RMAN> RUN{
    allocate channel c1 type 'SBT_TAPE';
    backup tablespace users;
    It gets struckup for more than two hours it didn't prompt any errors.
    allocated channel: c1
    channel c1: sid=13 devtype=SBT_TAPE
    channel c1: MMS Version 2.2.0.1
    Starting backup at 11-APR-02
    channel c1: starting full datafile backupset
    channel c1: specifying datafile(s) in backupset
    input datafile fno=00007 name=/gloqm/oradata/ORA9011/users01.dbf
    channel c1: starting piece 1 at 11-APR-02
    LSM was intalled, Is it right to mention the tape is 'SBT_TAPE' or i will have to mention something different.
    Could any one help
    Thanks in Advance
    gandhi

    For RMAN topics, please use: {forum:id=74}.

  • RMAN Backup to TSM

    I am looking into Oracle Database which use RMAN backup directly to tape (TSM). Before I never worked with TMS (Tivoli) and looking for simple command which I could run from UNIX prompt to see what is available on tape what files, directories…
    Any help would be appreciated.
    My Oracle version 8.1.7 and OS: AIX

    Unfortunately there's no 'simple command'. You have to study the documentation for this TSM API:
    http://www.redbooks.ibm.com/abstracts/sg246249.html
    Werner

  • RMAN restore from monthly tape backup

    hello!
    i have one more question regarding rman and tape backups: we don't want to store the rman recovery information in a separate database, so all the information is in the control files. but for revision we need to save one full backup per month. in addition to the databases we need files from different servers etc. on this tape-backups. so we decided to keep one tape set per month in a safe place -> is it possible to restore a rman backup from this tapes, e.g. 3 years afterwards (on a different machine)? thanks.
    bye,
    christian

    Hi christian,
    Can you give more info?
    As I understand it you do not want to use a recovery catalog ("we don't want to store the rman recovery information in a separate database").
    But if you store the rman backup info in the controlfile only you will limit the amount of rman information to your init parameter control_file_record_keep_time.
    Do you make rman backups to tape directly using a MML or do you make rman backups to disk which than get copied to tape (OS backup)?
    Regards,
    Tycho

  • Restoring RMAN backup from tape beyond retention policy ??

    Hello Friends,
    I just stuck in some basic finding. Need your help to resolve the questions.
    How we can use RMAN backup to restore oracle database when the RMAN backup pushed to tape already and being a OLD backup ( before retention policy date).
    Just to elaborate a more..  Say my retention policy is 3 days. I want to restore from a old backup  like 30 days old.
    So surely the requesting backup is behind retention date and has been pushed to tape.
    Please suggest.
    Thanks in advance.
    Regards
    Sinha.

    dba.arnab wrote:
    Hello Friends,
    I just stuck in some basic finding. Need your help to resolve the questions.
    How we can use RMAN backup to restore oracle database when the RMAN backup pushed to tape already and being a OLD backup ( before retention policy date).
    Just to elaborate a more..  Say my retention policy is 3 days. I want to restore from a old backup  like 30 days old.
    So surely the requesting backup is behind retention date and has been pushed to tape.
    Please suggest.
    Thanks in advance.
    Regards
    Sinha.
    Assuming the actual backup files still exist (the only thing actually deleted is the record of them in the catalog), you can make those files available and use the rman 'catalog' command to re-catalog them.

  • How to check the size of rman backups to tape

    instead of asking tsm person to check, how do I check how big is a rman backup sent to tape?

    query to find the backupset sizes
    SQL> select ctime "Date"
      2       , decode(backup_type, 'L', 'Archive Log', 'D', 'Full', 'Incremental') backup_type
      3       , bsize "Size MB"
      4  from (select trunc(bp.completion_time) ctime
      5          , backup_type
      6          , round(sum(bp.bytes/1024/1024),2) bsize
      7     from v$backup_set bs, v$backup_piece bp
      8     where bs.set_stamp = bp.set_stamp
      9     and bs.set_count  = bp.set_count
    10     and bp.status = 'A'
    11     group by trunc(bp.completion_time), backup_type)
    12  order by 1, 2;
    Date      BACKUP_TYPE    Size MB
    03-JUL-10 Archive Log       7.31
    03-JUL-10 Full             29.81
    03-JUL-10 Incremental    2853.85
    04-JUL-10 Archive Log       3.59
    04-JUL-10 Full              7.45
    04-JUL-10 Incremental       3.05

  • RMAN backup slow

    Hi,
    I have a Production Database (10204) running on HP Unix (B.11.11).
    Daily morning 6AM, a full RMAN backup runs. The db size is only around 225GB. But it takes 4.5 hours to complete.
    The syntax which I use is given below.
    RMAN> run {
         allocate channel ch1 type "sbt_tape";
         allocate channel ch2 type "sbt_tape";
         allocate channel ch3 type "sbt_tape";
    send
    'NB_ORA_CLIENT=jjcprd04-back.backup.ncsus.jnj.com,NB_ORA_POLICY=JJCPRD04-RMAN';
         backup
         format 'bk_%s_%p_%t'
         (database include current controlfile);
         sql 'alter system archive log current';
         backup
         format 'arch_%d_%s_%p_%t'
         (archivelog all delete input );
    Is there a way to increase the speed of this backup? Currently the backup is way too slow as it takes 4.5 hours to copy 225GB of data!
    Thanks!

    I'll start by stating that backups directly to tape are generally quite slow.
    I'd still recommend moving to disk backups though... and just archiving it to a tape...Hi Jony,
    You can of course backup to disk. Thats a common solution. But you have to deal with space more than everything. In addition to that backing up to disk does not free you from moving/copying your data - depending on your backup strategy - to a long-term storage.
    So you have two different and not conjunct backup operations: the rman backup itself and the job which backups the rman area to another media.
    In recovery cases you might end up with RMAN requesting older backupsets which are not on disk anymore. This will most probably lead to recovery failures and manual intervention which is not desirable in recovery scenarios.
    Another point is the control of the data flow. Backing up via a MML (i.e. "to tape") does not necessarily mean "to tape". Instead it means "to the backup software" which is responsible for managing the backup data. Common scenarios involve backing up the full backups via SAN directly to tape and backing up the archivelogs or incremental backups over LAN which will be stored by the backup software on a hard disk and later copied and/or moved on to tape. The data flow (to SAN / to disk / whereever) is solely controlled by the backup software.
    The advantage here is one continuous backup and restore job. The backup software deals with "where is my saveset located" and requests automatically the needed tapes or disks in recovery scenarios. This makes recoveries far more flexible and comfortable.
    Regarding the throughput i have set up a rather large OLTP database ( 12 TB currently) which is backed up with EMC Networker. Full backups are written via SAN directly to tape. The average speed with four LTO-3 drives is approx. 550 MB/s (the tape drives compress the data in hardware; the database itself is text-only and seems rather good compressable). I guess thats not too bad.
    you can also compress the BACKUPSETS (this generates a little more CPU but less network IO)He said he is on HP-UX. These kind of CPUs tend to be not that fast. Using compression is an option worth testing but there is another point to test when doing compressed backups: The RESTORE TIME.
    Ronny Egner
    My Blog: http://blog.ronnyegner-consulting.de

  • Need Advice on RMAN backup script

    Hi;
    Can any one advice if any error or guide to make RMAN backup proper :
    Backup Policy are:
    1.     0 level backup
    2.     current log file is arvhived before backing up
    3.     backup whole database (datafiles)
    4.     backup separate control file
    5.     backup is done on disk
    6.     control file auto backup ON
    7.     only 7 days archive log are need to be preserve ; old need to be deleted
    ### one time paramters seting
    RMAN> CONFIGURE DEFAULT DEVICE TYPE TO DISK;
    RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 2;
    RMAN> CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO 'O:\rman\backup\Auto_Ctrl_weekly_%F';
    RMAN> CONFIGURE CONTROLFILE AUTOBACKUP ON;
    ### Command for weekly 0 level backup
    run {
    allocate channel c1 type disk;
    sql 'alter system archive log current';
    backup incremental level 0 tag = weekly_database format 'o:\rman\backup\full_weekly_%d_%s_%p_%t'(database);
    release channel c1;
    configure controlfile autobackup format for device type disk to 'o:\rman\backup\auto_ctrl_weekly_%f';
    allocate channel c1 type disk;
    backup tag = weekly_arch archivelog until time 'sysdate-7' format 'o:\rman\backup\archive_weekly_%d_%s_%p_%t';
    delete archivelog until time 'sysdate-7';
    release channel c1;
    Regards
    Smith

    Dear Pierre F.;
    Actually, I just added in my backup plan to have daily backup through RMAN, instead of COLD backup.
    I have planned to take cold backup once a week. here is the side of data:
    *** datafile 410
    *** size of database : 86 GM
    *** relog files size : 250MB
    *** daily archive logs are : 250MB * 4(number of files) = 1GM aprox.
    yes, time constraint is there; just because of the size of database. and we r going for 24/7
    Is this script going to run only one per week ?
    Ans: no I this was level 0 backup; i will take level 1 incremental backup with same script daily too.
    Do you have any other RMAN script ?
    ANS: no, I will modify same script for incremental.
    after local copy of backup all backup files (RMAN) will be copy over network to backup server or we can install LTO tape device to copy directly from database server.
    kindly advise me I am new in RMAN.
    regards;
    SMITH

  • How to ensure the rman backup is successful?

    Hi,
    we have scheduled rman backup jobs.
    1. But how do we ensure all the rman backups are successful?
    2. if the rman writes directly to tape, how do we ensure all tape backups are successful?
    thanks
    andrew

    But what is incremental merge, couldn't find in the 10g manual?check it out on http://download.oracle.com/docs/cd/B28359_01/backup.111/b28270/rcmquick.htm#BRADV89354
    do you use image backup in real production environment?Of course. We have a standard to to use image copies that way.
    what do you suggest to do with rman normal way of backup or go for image backup?Depends on your specific situation. Like anything else, I prefer to provide some rationale on the recommendation.
    Image Copies with Incremental Merge
    Pros:
    (1) one one full backup taken ever; no need to take another full backup
    (2) the restore time is the same, regardless of the day of the week the db failed
    (3) every day the incremental merge's success means the backup was good - an automatic validation
    (4) it allows you to quickly switch to copy, rather than restore
    Cons:
    (1) Space requirement is more (since it's a bit to bit copy)
    (2) can't do a point in time recovery from the disk alone
    (3) can't go to the tape directly; must be a disk based backup.
    Backupsets with Incremental Backup
    Pros:
    (1) space requirement is lower (since only never-used blocks are not copied)
    (2) point in time recovery is possible
    (3) direct backup to tape possible (no need for disk backup)
    Cons:
    (1) restore time varies depending on the day of the week the db failed
    (2) you have to take a full backup regularly, perhaps once a week
    (3) no validation unless you use validate backupset (takes resources)
    So, as you can see, there are pros and cons to each approach. You have to decide for yourself which one weighs more (or less) to come to a conclusion.
    Hope this helps.
    Arup Nanda

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