A detailed overview of creating SAN volumes on a R/Evolution RAIDar box.

We have a mix of SAN hardware: R/Evolution RAIDar boxes and Nexsan boxes. This page outlines the procedures for R/Evolution RAIDar boxes.

Terminology

R/Evolution documentation refers to volumes and vdisks - but don't confuse SAN volumes with AFS volumes! A vdisk is a container for volumes, and is equivalent to a Nexsan array. A Virtual Disk or "vdisk" (Nexsan "array") contains "volumes" (Nexsan "volumes") which contain filesystems which contain data (usually AFS volumes).

Note that R/Evolution admin can be carried out via the GUI web page (for example, http://evobox1/) or the Command Line Interface. For example, to connect to the CLI for kbevo1a:

    example% telnet evobox1.inf.ed.ac.uk
    Trying 129.xxx.yyy.zzz...
    Connected to evobox1.inf.ed.ac.uk.
    Escape character is '^]'.
    Login: ADMIN
    Password: <passwd here>

      R/Evo 2730-2R
    System Name: evobox1
    System Location: Evoland
    Version: W420P63
    #

Creating a Virtual Disk

First, identify the disk space (see below): decide on the size of the vdisk and RAID level (which will affect the amount of final data space). It may be helpful to look at the GUI enclosure view, to see how the disks are currently used.

Virtual Disks can be created "online" or "offline". When "online", you can begin using the virtual disk immediately after creating it (while the virtual disk initialization process is still running). This is the default.

Note that this process can take a long time for large vdisks (up to 3 days for 6Tb!), but the vdisk can be used during this period if created "online".

GUI method:

  • From the "Manage: create a vdisk" page, select "Manual Virtual Disk Creation"
  • Enter the Virtual Disk Name and RAID level, then hit "Create Virtual Disk" button. You'll get a "Processing..." window, and then an Enclosure View to select disks.
  • Choose disks to add to the Virtual Disk (select tick-boxes of disks - available disks are coloured green). No need to "add dedicated spare drives for this virtual disk" unless required.

Select disks with care - although you will only be able to select "Available" disks (hover over the "i" icon, and you should see "Part of Vdisk: Available", and an "A" on the disk). You can also note the serial number from the "i" information, which can be of use when checking via the CLI.

Once disks are selected, click "Continue" - this takes you to the final "Create Virtual Disk" button, where details of the not-yet-created vdisk are displayed. For example:

    Virtual Disk Name:                  Array 3a
    RAID Level:                         5
    Virtual Disk Size:                  208036.38 GBytes

    Drives Chosen:    
        Serial Number   Size (GBytes)   Encl.Slot
        JK11A8B9KEW1NF  2000.40         3.0
        JK11A8B9KETRGF  2000.40         3.1
        JK11A8B9KEU01F  2000.40         3.2
        JK11A8B9KEK1BF  2000.40         3.3

    Dedicated Spare Drives Chosen:      None Selected
    Virtual Disk Initialization:        Online

...if the details are correct, create the vdisk.

CLI method

Commands you'll need:

  • " show disks free "
  • " create vdisk level Level disks <diskM-diskN> Vdisk "

Once connected to the CLI:

  • Type "show disks free" to display available disks - this will give a list of disks, including serial number and ID

For example:

    ID Serial#               Vendor   Rev. State      Type Size(GB) Rate(Gb/s) SP Status    
    ----------------------------------------------------------------------------------------
    48 JK11A8B9KEW1NF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    49 JK11A8B9KETRGF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    50 JK11A8B9KEU01F        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    51 JK11A8B9KEK1BF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    52 JK11A8B9KB4N4F        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    53 JK11A8B9KEU02F        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    54 JK11A8B9KELKMF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    55 JK11A8B9KERVRF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    56 JK11A8B9KATMNF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    57 JK11A8B9KEHSYF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    58 JK11A8B9KEEHXF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    59 JK11A8B9KESGXF        ATA      A3EA AVAIL      SATA 2000     3.0          Up        
    ----------------------------------------------------------------------------------------
    # 
  • Choose the disks you want to use, note their IDs
  • Decide on the vdisk name and RAID level
  • Run " create vdisk level raid5 disks <diskM-diskN> Vdisk " to create a RAID 5 vdisk called "Vdisk" from disks with IDs M to N (where the disk IDs are taken from the free disks list, and can be checked with serial numbers via the GUI).

For example:

    # create vdisk level raid5 disks 48-51 "Array 3a"
    Success: Vdisk created.
    # show vdisks "Array 3a"
    Name                 Size     Free     Own RAID   Dsk Spr Chk Stat Jobs      
      Serial#                          
    -----------------------------------------------------------------------------
    Array 3a             5995.1GB 5995.1GB B   RAID5  4   0   64  CRIT INIT 0%   
      00c0ff0a6a7b0048341b184f00000000 
    -----------------------------------------------------------------------------
    # 
(this will create a vdisk "Array 3a", using four disks, with a total size of 6Tb). Note that "Stat"us is CRITical, and "Jobs" is INITialising, but the new vdisk is usable.

Be careful when using the disk size values: the suffixes TB, GB, & MB can be evaluated in binary (x1024) or decimal (x1000) mode - the latter being the default. You also need to double-check the size if duplicating an existing volume elsewhere (the Nexsan, for example, uses 729700 MB, 729.7 GB, 679.5 GiB - which are all equivalent).

Creating a volume

CLI method

Once connected to the CLI, create the volume and export ("map") it to the relevant host(s)

  • Create the volume with " create volume vdisk Vdisk size Size MB Volume "

...where Vdisk is the vdisk name, Volume is the volume name, and Size is the volume size in MB (or GB or TB). For example:

    # create volume vdisk "Array 3a" size 1143000MB pyrolisk-vicepm
    Success: volume created with no mapping
    # show volumes vdisk "Array 3a"                                
    Vdisk                Volume Name          Size     WR Policy    Class    
      Volume Serial Number              Cache Opt    Type         
    -------------------------------------------------------------------------
    Array 3a             pyrolisk-vicepm      1143.0GB writeback    standard 
      00c0ff0a6a7b00483b5d1d4f01000000  standard     standard     
    -------------------------------------------------------------------------
    # 
...this will create a volume called "pyrolisk-vicepm" within the "Array 3a" vdisk, with a size of 1.1Tb.

  • Choose host to map/export to (WWN-name)
  • Choose LUN (SCSI ID)
  • Choose port access rights (whether Read-Write or Read-Only).

...the host names used for mapping (exporting) should already be defined. Use the " show host-wwn-names " command to list available names, and choose one (or, rather, a pair - they normally come in pairs for the dual-port connections).

...the LUN (which is used as the SCSI ID by the host) should ideally be unique across the SAN, but it doesn't have to. However, it must be unique across the mapped host(s). Use something like " lsscsi " to check LUNs on corresponding host(s).

Use the " show volume-maps " command to list all volumes with associated LUNs, and choose the next available (the first one not in the list).

Assuming that you want to export RW (the default), using LUN 31, an example command would be:

    # map volume pyrolisk-vicepy mapping 0-1.31 host pyrolisk-port0
    # map volume pyrolisk-vicepy mapping 0-1.31 host pyrolisk-port1

This exports the volume "pyrolisk-vicepy" to both ports on pyrolisk, using both channels (0-1) on the SAN, with LUN (SCSI ID) 31. Once this is complete, attention shifts from the SAN to the host.

-- RogerBurroughes - 06 Feb 2012

Topic revision: r5 - 16 Jan 2013 - 12:49:05 - RogerBurroughes
 
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