RMAN very slow
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  1. #1
    Join Date
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    RMAN very slow

    Hi Friends,
    Oracle version 8.1.7.4, sun 2.8

    We are using RMAN to backup the DB, our DB size is 500GB and have totally 610 DB files, most of them are 1GB in size.

    During backup, backup of each files takes close to 10 Min. The backup is on a SAN storage and are in RAID-5.The storage is interconnected using FIBRE CHANNEL.

    Right now to increase the speed of backup i am analyze the BACKUP schema.

    Is there any way that i can do to increase the speed of backup.

    RMAN CATALOG is on a different m/c

    regards
    anandkl
    anandkl

  2. #2
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    HOw many channels are you opening? Have you tried backup with multiple channels simulataneously..
    Sanjay G.
    Oracle Certified Professional 8i, 9i.

    "The degree of normality in a database is inversely proportional to that of its DBA"

  3. #3
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    Hi Sanjay,
    Initial i tried with 8 channels, then i tried with 2 and finally i tried with one , but the result is same.

    regards
    anandkl
    anandkl

  4. #4
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    I wonder using different no. of channels produce same result, can you post your RMAN script. Also, writing backup to RAID5 is not a very good choice.
    Sanjay G.
    Oracle Certified Professional 8i, 9i.

    "The degree of normality in a database is inversely proportional to that of its DBA"

  5. #5
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    Hi Sanjay
    This is the command i used and used the same to take backup by reducing the number of channels.
    run {
    allocate channel d1 type disk format='/bkdisk/rmanbkup/u01/db_t%t_s%s_p%p';
    allocate channel d2 type disk format='/bkdisk/rmanbkup/u02/db_t%t_s%s_p%p';
    allocate channel d3 type disk format='/bkdisk/rmanbkup/u03/db_t%t_s%s_p%p';
    allocate channel d4 type disk format='/bkdisk/rmanbkup/u04/db_t%t_s%s_p%p';
    allocate channel d5 type disk format='/bkdisk/rmanbkup/u05/db_t%t_s%s_p%p';
    allocate channel d6 type disk format='/bkdisk/rmanbkup/u06/db_t%t_s%s_p%p';
    allocate channel d7 type disk format='/bkdisk/rmanbkup/u07/db_t%t_s%s_p%p';
    allocate channel d9 type disk format='/bkdisk/rmanbkup/u09/db_t%t_s%s_p%p';
    set maxcorrupt for datafile

    212,1,2,3,4,5,6,7,8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35
    , 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,
    67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 82, 81, 86, 83, 84, 85, 87, 88, 90, 89, 92, 91, 96, 93, 94, 95,103,
    97, 98, 99,100,101,102,112,104,105,106,107,108,109,110,111,127,113,114,115,116,117,118,119,120,121,122,123,1 24,125,126,129,12
    8,131,130,134,132,133,135,138,136,137,139,140,142,141,145,143,144,162,146,147,148,149,150,151,152,15 3,154,155,156,157,158,159
    ,160,161,165,163,164,181,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,184,182,183,185 ,186,188,187,189,190,191,
    192,194,193,195,196,197,202,198,199,200,201,205,203,204,206,215,207,208,209,210,214,216,217,218,220, 219,221,222,223,211,213,2
    24,225,226,227,229,228,230,231,232,233,234,235,236,237,263,238,239,240,241,242,243,244,245,246,247,2 48,249,250,251,252,253,25
    4,255,256,257,258,259,260,261,262,265,264,266,268,267,270,278,279,280,281,283,284,271,272,269,273,27 4,275,282,285,286,276,277
    ,287,288,289,290,291,292,293,294,295,296,297,298,299,300,301,302,303,304,305,306,307,308,309,310,311 ,312,313,314,315,316,317,
    318,319,320,321,322,323,324,325,326,327,328,329,330,331,332,333,334,335,336,337,338,339,340,341,342, 343,344,345,346,347,348,3
    49,350,351,352,353,354,355,356,357,358,359,360,361,362,363,364,365,366,367,368,369,370,371,372,373,3 74,375,376,377,378,379,38
    0,381,382,383,384,385,386,387,388,389,390,391,392,393,394,395,396,397,398,399,400,401,402,403,404,40 5,406,407,408,409,410,411
    ,412,413,414,415,416,417,418,419,420,421,422,423,424,425,426,427,428,429,430,431,432,433,434,435,436 ,437,438,439,440,441,442,
    443,444,445,446,447,448,449,450,451,452,453,454,455,456,457,458,459,460,461,462,463,464,465,466,467, 468,469,470,471,472,473,4
    74,475,476,477,478,479,480,481,482,483,484,485,486,487,488,489,490,491,492,493,494,495,496,497,498,4 99,501,505,506,508,511,51
    2,515,516,517,520,521,525,530,533,534,536,538,542,545,546,549,553,554,555,557,558,560,561,562,563,56 4,565,566,567,568,569,570
    ,572,573,574,575,576,577,578,579,580,581,582,583,584,585,586,587,588,591,592,593,594,595,596,599,602 ,605,606,610,611 to 100;

    backup
    full
    filesperset 1
    tag full_us
    (database);

    release channel d9;
    release channel d7;
    release channel d6;
    release channel d5;
    release channel d4;
    release channel d3;
    release channel d2;
    release channel d1;
    }
    anandkl

  6. #6
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    First Time in my life I see backup is stored on RAID 5.

    When RAID 5 is not even suitable for Oracle datafiles, how did you find out it is a good backup media ?

    Get rid of RAID 5. Stripe the disks that are used for backups. Use Stripe size 512KB or 1MB per disk.

    You will be OK.

    Tamil

  7. #7
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    Originally posted by tamilselvan
    First Time in my life I see backup is stored on RAID 5.

    My what a sheltered life you have.


    When RAID 5 is not even suitable for Oracle datafiles, how did you find out it is a good backup media ?
    RAID 5 is great, when used appropriately. If your host can't drive the RAID 5 to capicity (like over NFS or on a really busy host), RAID 5 is more than adequate.


    You don't mention what your bottleneck is.
    Backup Disks 100% busy: No - RAID 5 fine. Yes - rethink RAID 5.
    Database Disks 100% busy: Yes - Less threads, limit readrate, reduce multiplexing.
    CPU Swamped: Yes - less threads. No - more threads.
    Fibre Flooded: Yes - less threads, No - more threads.
    etc, etc, etc.
    Jeff Hunter
    marist89@yahoo.com
    http://marist89.blogspot.com/
    Get Firefox!
    "I pledge to stop eating sharks fin soup and will not do so under any circumstances."

  8. #8
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    What about increasing the value of

    filesperset 1 to a higher one ( to 3 or 4)?

    Thomas
    Thomas Saviour(royxavier@yahoo.com)
    Technical Lead (Databases)
    Thomson Reuters (Markets)

    http://ora600tom.wordpress.com/

  9. #9
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    Hi Marist89,
    What do you mean by SHELTERED life.

    I will try these options and will get back.

    regards
    anandkl
    anandkl

  10. #10
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    In this sense, sheltered = "not exposed to very much"
    Jeff Hunter
    marist89@yahoo.com
    http://marist89.blogspot.com/
    Get Firefox!
    "I pledge to stop eating sharks fin soup and will not do so under any circumstances."

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