Results 1 to 6 of 6
  1. #1
    Join Date
    May 2003
    Posts
    369

    Unanswered: Time for restore of 500Gb database?

    We are planning to test our restore for disaster recovery tests this year. The environment is running DB2 UDB 7.2 32bit with Fixpack6 on AIX 5.2L 32 bit. The database size is 500Gb. We have a good backup image stored on our IBM Tivoli TSM server on disk. Questions:

    1. How long would the restore process take to restore from TSM if the image is on an ESS Shark disk array?

    2. Granted that we also back up onto tape, how long would it take to restore the database (500Gb) from tape?

    I need to include these time estimates into our DR project plan.

    Thanks!
    Scott

  2. #2
    Join Date
    Aug 2001
    Location
    UK
    Posts
    4,650

    Re: Time for restore of 500Gb database?

    Personally, I would say there is no definitive answer .. A good DR plan should always be tested to get these details ... You should also make a note of the command you use(which will include the performace parameters) .

    The restore could depend on

    1. Your TSM Tape Libraries
    2. How much your database containers are spread across disks
    3. Your processor speed
    4. Your RAM
    5. BUFFERSIZE, NUMBUFFERS, UTIL_HEAP_SZ etc.

    Sorry for not being of much help

    Sathyaram


    Originally posted by mixxalot
    We are planning to test our restore for disaster recovery tests this year. The environment is running DB2 UDB 7.2 32bit with Fixpack6 on AIX 5.2L 32 bit. The database size is 500Gb. We have a good backup image stored on our IBM Tivoli TSM server on disk. Questions:

    1. How long would the restore process take to restore from TSM if the image is on an ESS Shark disk array?

    2. Granted that we also back up onto tape, how long would it take to restore the database (500Gb) from tape?

    I need to include these time estimates into our DR project plan.

    Thanks!
    Scott
    Visit the new-look IDUG Website , register to gain access to the excellent content.

  3. #3
    Join Date
    Apr 2003
    Location
    Phoenix, AZ
    Posts
    177
    Start with the question "how long does it take to perform a full level 0 backup? From there you need other factors:

    1. If it's coming from TSM diskpool you can have multiple threads.
    2. If it's tape, it will "single stream".

    I've found that all other factors being equal, like network traffic, server(s) busy, etc. That a tablespace takes 1.5 times as long to restore as to backup.
    Fred Prose

  4. #4
    Join Date
    May 2003
    Posts
    369

    restore parameters and restore time?

    Here are more details:

    1. database size: 500Gb, DB2 UDB 7.2+FP6 (32 bit) on AIX 5.2L 32 bit

    2. backup method: full online DB2 backup to TSM
    db2 backup db mydb online use tsm

    2b. Hardware configuration: 4xCPU, 4Gb RAM memory for server
    IBM AIX 5.2L 32 bit

    3. the backup uses no special parameters and is backed up to an
    ESS SAN "Shark" disk array

    4. db2 restore db mydb
    db2 rollforward db to end of logs and stop

    We can put the tape restore aside for now and focus on time required for a simple restore from the ESS Shark using TSM and a simple full online backup. Any good time estimates to restore this db with the above parameters? Thanks! I need to incorporate this into a project plan for senior management and need some rough numbers.
    When I ran db2adutl verify full taken at ... it takes about 2 hours to verify that my restore image is good. Should I multiple this by a factor of 10 to get a good time estimate? So would it take 20hrs to restore this database from a full online backup from the ESS via TSM? Thanks!

    Scott

  5. #5
    Join Date
    Oct 2003
    Posts
    93
    Scott,
    My database is around 30 GB only.
    It takes me 40 min for offline backup and 1hr to restore.
    Like Fred said, your backup time will give you an good estimate how long it will take to restore...

  6. #6
    Join Date
    May 2003
    Posts
    369

    thanks

    My estimate would be for online restore of the 500Gb since backups take
    3hrs to run, the restore about 5-6hours. Will test to see.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •