Topic
  • 6 replies
  • Latest Post - ‏2010-01-29T07:49:44Z by SystemAdmin
SystemAdmin
SystemAdmin
706 Posts

Pinned topic Using Read/Write enable Virtual Optical Device

‏2010-01-22T04:20:56Z |
Hi,

I'm thinking of way to use VIOS's file-backed virtual optical device, for backing up my data.
First I've made a read-write enabled virtual disk on my VIOS(2.1.2.10-FP-22) and load it on my virtual target device.

$ lsrep
Size(mb) Free(mb) Parent Pool Parent Size Parent Free
10126 0 vopt_vg 10168 0

Name File Size Optical Access
SLES11_DVD1 2885 None rw
SLES11_DVD2 3734 None rw
rw_device 3507 lpar510_cd rw

(the "rw_device" is the virtual disk, and "lpar510_cd" is the virtual target device)

However on when i try to format the disk on my SLES 11 machine I get the flowing error indicating me that "controller does not support CD write parameter page."

lpar510:~ # cdrecord -scanbus
scsibus0:
0,0,0 0) 'AIX ' 'VOPTA ' '' Removable CD-ROM
0,1,0 1) *
0,2,0 2) *
0,3,0 3) *
0,4,0 4) *
0,5,0 5) *
0,6,0 6) *
0,7,0 7) *
lpar510:~ # cdrecord blank=fast dev=0,0,0
WARNING: the deprecated pseudo SCSI syntax found as device specification.
Support for that may cease in the future versions of wodim. For now,
the device will be mapped to a block device file where possible.
Run "wodim --devices" for details.
Device type : Removable CD-ROM
Version : 4
Response Format: 2
Capabilities : CMDQUE
Vendor_info : 'AIX '
Identification : 'VOPTA '
Revision : ''
Device seems to be: Generic CD-ROM.
wodim: Sorry, no CD/DVD-Recorder or unsupported CD/DVD-Recorder found on this target.
Using generic SCSI-2 CD-ROM driver (scsi2_cd).
Driver flags :
Supported modes:
wodim: Warning: controller does not support CD write parameter page.
wodim: Cannot set speed/dummy.

My Question:

・ Is there any information that Linux(on Power) does not support writing on virtual disks?

Thanks,
Updated on 2010-01-29T07:49:44Z at 2010-01-29T07:49:44Z by SystemAdmin
  • SystemAdmin
    SystemAdmin
    706 Posts

    Re: Using Read/Write enable Virtual Optical Device

    ‏2010-01-24T23:37:22Z  
    a little bit of more info,
    checked the /proc directory, and it seems that writing is not supported

    1. cat /proc/sys/dev/cdrom/info
    CD-ROM information, Id: cdrom.c 3.20 2003/12/17

    drive name: sr0
    drive speed: 1
    drive # of slots: 1
    Can close tray: 1
    Can open tray: 1
    Can lock tray: 1
    Can change speed: 0
    Can select disk: 0
    Can read multisession: 1
    Can read MCN: 1
    Reports media changed: 1
    Can play audio: 1
    Can write CD-R: 0
    Can write CD-RW: 0
    Can read DVD: 0
    Can write DVD-R: 0
    Can write DVD-RAM: 0
    Can read MRW: 0
    Can write MRW: 0
    Can write RAM: 0

    from this may I conclude that you CANNOT write on a virtual disk?

    thanks,
  • SystemAdmin
    SystemAdmin
    706 Posts

    Re: Using Read/Write enable Virtual Optical Device

    ‏2010-01-26T16:53:30Z  
    a little bit of more info,
    checked the /proc directory, and it seems that writing is not supported

    1. cat /proc/sys/dev/cdrom/info
    CD-ROM information, Id: cdrom.c 3.20 2003/12/17

    drive name: sr0
    drive speed: 1
    drive # of slots: 1
    Can close tray: 1
    Can open tray: 1
    Can lock tray: 1
    Can change speed: 0
    Can select disk: 0
    Can read multisession: 1
    Can read MCN: 1
    Reports media changed: 1
    Can play audio: 1
    Can write CD-R: 0
    Can write CD-RW: 0
    Can read DVD: 0
    Can write DVD-R: 0
    Can write DVD-RAM: 0
    Can read MRW: 0
    Can write MRW: 0
    Can write RAM: 0

    from this may I conclude that you CANNOT write on a virtual disk?

    thanks,
    Hi, we're currently investigating this. We'll provide more definitive information in this thread shortly.
  • SystemAdmin
    SystemAdmin
    706 Posts

    Re: Using Read/Write enable Virtual Optical Device

    ‏2010-01-27T09:25:34Z  
    Thank you for your support,

    Here's more information if it helps.

    When mapping a physical cd drive to a virtual optical device, the driver information says that it is capable of writing DVD-RAMs. (only)

    <FROM VIOS >
    ( lp48_cd is File-backed optical device, vopt0 is a virtual scsi device mapped to a physical cd)

    lsmap -vadapter vhost5
    SVSA Physloc Client Partition ID

    --------------------------------------------
    vhost5 U9131.52A.067F69G-V1-C108 0x00000008

    VTD lp48_cd
    Status Available
    LUN 0x8100000000000000
    Backing device /var/vio/VMLibrary/RHEL53
    Physloc

    VTD lp48_sda_SAN
    Status Available
    LUN 0x8300000000000000
    Backing device hdisk8
    Physloc U7311.D20.066698B-P1-C07-T1-W200600A0B8502F3D-L6000000000000

    VTD vtopt0
    Status Available
    LUN 0x8200000000000000
    Backing device cd0
    Physloc U787F.001.DPM35L8-P4-D2

    <From RHEL 5.3 >

    lsvio -d
    300000d0 v-scsi U9131.52A.067F69G-V8-C208-T1
    1:0:2:0 sg1 sdb U9131.52A.067F69G-V8-C208-T1-L1-L0
    3000006c v-scsi U9131.52A.067F69G-V8-C108-T1
    0:0:2:0 sg3 sr1 U9131.52A.067F69G-V8-C108-T1-L0-L0
    0:0:1:0 sg2 sr0 U9131.52A.067F69G-V8-C108-T1-L0-L0
    0:0:3:0 sg0 sda U9131.52A.067F69G-V8-C108-T1-L0-L0

    cat /proc/sys/dev/cdrom/info
    CD-ROM information, Id: cdrom.c 3.20 2003/12/17

    drive name: sr1 sr0
    drive speed: 24 1
    drive # of slots: 1 1
    Can close tray: 1 1
    Can open tray: 1 1
    Can lock tray: 1 1
    Can change speed: 1 0
    Can select disk: 0 0
    Can read multisession: 1 1
    Can read MCN: 1 1
    Reports media changed: 1 1
    Can play audio: 1 1
    Can write CD-R: 0 0
    Can write CD-RW: 0 0
    Can read DVD: 1 0
    Can write DVD-R: 0 0
    Can write DVD-RAM: 1 0
    Can read MRW: 1 0
    Can write MRW: 1 0
    Can write RAM: 1 1

    sr1 shows that it can handle DVD-RAM

    Thanks,
  • SystemAdmin
    SystemAdmin
    706 Posts

    Re: Using Read/Write enable Virtual Optical Device

    ‏2010-01-27T09:29:43Z  
    Thank you for your support,

    Here's more information if it helps.

    When mapping a physical cd drive to a virtual optical device, the driver information says that it is capable of writing DVD-RAMs. (only)

    <FROM VIOS >
    ( lp48_cd is File-backed optical device, vopt0 is a virtual scsi device mapped to a physical cd)

    lsmap -vadapter vhost5
    SVSA Physloc Client Partition ID

    --------------------------------------------
    vhost5 U9131.52A.067F69G-V1-C108 0x00000008

    VTD lp48_cd
    Status Available
    LUN 0x8100000000000000
    Backing device /var/vio/VMLibrary/RHEL53
    Physloc

    VTD lp48_sda_SAN
    Status Available
    LUN 0x8300000000000000
    Backing device hdisk8
    Physloc U7311.D20.066698B-P1-C07-T1-W200600A0B8502F3D-L6000000000000

    VTD vtopt0
    Status Available
    LUN 0x8200000000000000
    Backing device cd0
    Physloc U787F.001.DPM35L8-P4-D2

    <From RHEL 5.3 >

    lsvio -d
    300000d0 v-scsi U9131.52A.067F69G-V8-C208-T1
    1:0:2:0 sg1 sdb U9131.52A.067F69G-V8-C208-T1-L1-L0
    3000006c v-scsi U9131.52A.067F69G-V8-C108-T1
    0:0:2:0 sg3 sr1 U9131.52A.067F69G-V8-C108-T1-L0-L0
    0:0:1:0 sg2 sr0 U9131.52A.067F69G-V8-C108-T1-L0-L0
    0:0:3:0 sg0 sda U9131.52A.067F69G-V8-C108-T1-L0-L0

    cat /proc/sys/dev/cdrom/info
    CD-ROM information, Id: cdrom.c 3.20 2003/12/17

    drive name: sr1 sr0
    drive speed: 24 1
    drive # of slots: 1 1
    Can close tray: 1 1
    Can open tray: 1 1
    Can lock tray: 1 1
    Can change speed: 1 0
    Can select disk: 0 0
    Can read multisession: 1 1
    Can read MCN: 1 1
    Reports media changed: 1 1
    Can play audio: 1 1
    Can write CD-R: 0 0
    Can write CD-RW: 0 0
    Can read DVD: 1 0
    Can write DVD-R: 0 0
    Can write DVD-RAM: 1 0
    Can read MRW: 1 0
    Can write MRW: 1 0
    Can write RAM: 1 1

    sr1 shows that it can handle DVD-RAM

    Thanks,
    Sorry,
    forgot to explain that above was tested on a different machine, which RHEL 5.3.

    Still both, SLES11 and RHEL 5.3 reports, writing aren't supported

    thanks,
  • Brian_King
    Brian_King
    20 Posts

    Re: Using Read/Write enable Virtual Optical Device

    ‏2010-01-28T18:30:45Z  
    Sorry,
    forgot to explain that above was tested on a different machine, which RHEL 5.3.

    Still both, SLES11 and RHEL 5.3 reports, writing aren't supported

    thanks,
    After some investigation, we've been able to reproduce the problem you are having. Unfortunately, we don't currently have a fix or workaround. I would encourage you to open a PMR for this issue. As an alternative, would using a logical volume backed virtual disk for your backup be a possible solution?
  • SystemAdmin
    SystemAdmin
    706 Posts

    Re: Using Read/Write enable Virtual Optical Device

    ‏2010-01-29T07:49:44Z  
    After some investigation, we've been able to reproduce the problem you are having. Unfortunately, we don't currently have a fix or workaround. I would encourage you to open a PMR for this issue. As an alternative, would using a logical volume backed virtual disk for your backup be a possible solution?
    Thank you very much for your support!

    I understand the situation for no fix or workaround.

    As for the alternative, actually i was unaware of "logical volume backed virtual disk".
    I'll try it out, and give feedback.

    Thank you,