bobr5

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bobr5

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April 24th, 2008 12:00

Changing RAID level

I have a couple LUNs created as RAID 1/0 (unused, not going to be used). Can I just change them to RAID 5 for another server we want to attach or do I need to destroy those LUNs and recreate them?
TIA
  • kelleg

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    Posted April 25th, 2008 12:00

    Once you bind the first LUN in a new Raid Group, the Raid Group gets set to the raid type of the LUN. To change the raid type for a LUN, you can unbind all the LUNs in the raid group and the bind new LUNs with a different raid type. Or you can migrate the LUNs to a different LUN in a different Raid Group with the raid type you want.

    regards,

    glen kelley
  • dynamox

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    Posted April 24th, 2008 12:00

    you could migrate them to RAID-5 LUNs using Lun Migrator in NaviSphere ..or like you said delete/recreate.
  • Kiran3

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    Posted April 24th, 2008 20:00

  • RRR

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    Posted May 7th, 2008 06:00

    Is your question answered by now ?

    I guess you only have 2 options:
    - migrate RAID10 LUN's to RAID5 LUN's to preserve data
    - unbind RAID10 LUN's and recreate RAID5 LUN's if data isn't needed anymore.
  • dynamox

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    Posted December 17th, 2009 07:00

    you could delete spare and create LUNs on one disk but are you willing to take the chance of losing data if that drive fails ?
  • Lynny1

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    Posted December 17th, 2009 07:00

    I'm sorry please explain I dont understand. What do you mean loosing a chance of loosing data that resides in spare drive?

    I am not too familiar on how to use the spare drive never use it before. Please explain and answer.

    Can you create a regular disk drive Raid 10 or Raid 5 on a spare drive?

    Can I create a multiple disk of Raid 5 or 10 using the spare drive?

    I just want to move the data from a bad performing disk temporarily to a good disk until I reformated the orginal disk?

    I am thinking to perform LUN migration just to move the Data to the newly created disk which is the spare disk when the data is there intact with no problem

    reformat the original Disk Raid 10 and perform another LUN migration from the spare disk, what problem do you foreseen on this scenario because I have

    to do this in Production drive. Thank you for your help and let me know.

  • Lynny1

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    Posted December 17th, 2009 07:00

    Can you tell me if can I LUN migrate Raid 10 disk with data to a Spare drive? No available disk in the Clariion except the Spare Drive.

    Can I make the spare drive usuable like a normal disk like RAid 5?

    EMC says that the current disk have a preformance problem due a problem so this RAID 10 disk needs to be reformated and migrate

    the data first to a new LUN but I do not have anything available except the Spare.

    What should I do?

  • dynamox

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    Posted December 17th, 2009 07:00

    before we go down the road of deleting the spare drive, can you explain what EMC told you regarding performance and what did they advice you do ? Move to raid-5 configuration, different drives, more drive ?
  • Lynny1

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    Posted December 17th, 2009 10:00

    Wait I am trying to find the EMC case # stating t backup and restore this current V-drive (2.3 TB) create a new disk make it Raid 10 and restore the data due to performance problem. Description finding by EMC- I have the printed report by EMC here I will type it in I have no soft copy Im waiting for the case# too.

    UPS United Parcel Service - Clarion sn# APM00062603769- site ID 17736

    Case number? still waiting who opened this call Manish Arora of UPS

    He is from CPM Group in UPS - Capacity Performance Management

    CX3-80 Metalun Drive V LUN of meta of 7 luns each 468 GB made of 8 15krph FC disks

    Total IOPS this LUN can handle is 10,080 IOPS showing low IOPS

    LUN response time - graphs spiking

    LUN itulization the graphs looks spiking up high to 106

    Current Disk Utilization - its says Backend Disks are up to 60% MAX utilized

    number of stripe crossing - 783639393

    number un-used blocks prefetched 784735716

    EMC Analysis of Cluster server 0014\0015 Windows 2003 SP2 SAN switch going to Clarion CX3-80

    * Increase number of IOPS by 1000 IO's as compare to the last time

    * SPA utilization has increased from 44% MAX to 64% MAX

    * The IO type is still heavy Random Reads

    *The Read Cache hit is almost equals to 30% to 40%

    *Pre-fetched blocks are not been used due to random read IOPS

    *The drives are MAX 60% utilized

    *Disk crossing is occuring while reading or writing data as alignment offset is set to default zero

    Previous recommendation by EMC:

    *Due to the extreme amount of random reads, the Application needs to tune their Application

    *Current Recommendation:

    *Due to the extreme amount of random reads, the application needs to tune their application

    * Set the alignement offset to 64 KB in order to stop disk crossing

    *Can set the pre-fetch Multiplier to 2 or 0 on LUN 17 in order to stop pre-fetching blocks to read

    Note: there us a down-time required on both activities. For setting the alignment offset data needs ti backed up and restored.

    MY Question to EMC right now is - instead of backup and restore I want to do a LUN Migration instead but I do not have a 3.2

    TB on CX3--80 all I have are all spare drives. Can I use the spare drives to create a 2.3 LUNS to move the data temporary ONLY.

    Once the data is migrated from LUN 17 Raid 5 to the Spare disks - I will format the orginal disk LUN 17run diskpart and perform

    another lun migration move data from Spare disk to the newly formated LUN 17. Can you answer my question please,

    Can I create a 3.3 TB of metalun out of a sparedisk? YES or No?

  • Lynny1

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    Posted December 17th, 2009 10:00

    Got you thank you.