[dm-devel] state we don't understand

Fri Aug 2 04:45:01 UTC 2013

A thought:

In checking the model, only SCSI_PRODUCT_SIZE chars will be returned from
sysfs_get_model.  If the entire model strings are:

FlashArray:FC048517648240BB00010003
FlashArray:FC048517648240BB00010005

that's 36 characters, of which the first 35 look identical to me.

Even if "FlashArray:" is ignored, and the hex digits represent the product,
that's still 25 hex digits of which the first 24 look identical.

On Thu, Aug 1, 2013 at 4:16 PM, Brian Bunker <brian at purestorage.com> wrote:

> Hello all,
>
> Every once in a while we run into a situation like this and we have caught
> a machine in this state to hopefully gain some insight into what is wrong
> where causing this. We have a 'multipath -l' output like this:
>
> [root at r17init5 ~]# multipath -l
> ...
> mpathguk (3624a9370fc048517648240bb00010005) dm-4 PURE,FlashArray
> size=500G features='0' hwhandler='0' wp=rw
> `-+- policy='round-robin 0' prio=0 status=active
>   |- 2:0:0:7  sdar 66:176 active undef running
>   |- 0:0:0:7  sdba 67:64  active undef running
>   |- 3:0:0:5  sde  8:64   active undef running
>   `- 1:0:0:5  sdt  65:48  active undef running
> ...
> mpathgui (3624a9370fc048517648240bb00010004) dm-5 PURE,FlashArray
> size=500G features='0' hwhandler='0' wp=rw
> `-+- policy='round-robin 0' prio=0 status=active
>   |- 2:0:0:6  sdaq 66:160 active undef running
>   |- 0:0:0:6  sday 67:32  active undef running
>   |- 3:0:0:4  sdd  8:48   active undef running
>   `- 1:0:0:4  sds  65:32  active undef running
> ....
>
> You can see that the dm device is combining different LUN numbers under
> the same dm device which is obviously leading to data corruption. Some dm
> devices in the list do not have this problem. You can see that these should
> not be getting combined since their page 0x83 inquiry data is not the same:
>
> [root at r17init5 ~]# sg_inq -p 0x83 /dev/sdar
> VPD INQUIRY: Device Identification page
>   Designation descriptor number 1, descriptor length: 20
>     designator_type: NAA,  code_set: Binary
>     associated with the addressed logical unit
>       NAA 6, IEEE Company_id: 0x24a937
>       Vendor Specific Identifier: 0xfc048517
>       Vendor Specific Identifier Extension: 0x648240bb00010005
>       [0x624a9370fc048517648240bb00010005]
>   Designation descriptor number 2, descriptor length: 47
>     designator_type: T10 vendor identification,  code_set: ASCII
>     associated with the addressed logical unit
>       vendor id: PURE
>       vendor specific: FlashArray:FC048517648240BB00010005
>   Designation descriptor number 3, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Relative target port,  code_set: Binary
>     associated with the target port
>       Relative target port: 0x17
>   Designation descriptor number 4, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Target port group,  code_set: Binary
>     associated with the target port
>       Target port group: 0x0
>   Designation descriptor number 5, descriptor length: 8
>     designator_type: Logical unit group,  code_set: Binary
>     associated with the addressed logical unit
>       Logical unit group: 0x0
>   Designation descriptor number 6, descriptor length: 36
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: SCSI name string,  code_set: UTF-8
>     associated with the target port
>       SCSI name string:
>       naa.524a937000013316,t,0x0001
>   Designation descriptor number 7, descriptor length: 16
>     designator_type: vendor specific [0x0],  code_set: ASCII
>     associated with the addressed logical unit
>       vendor specific: validation4
>
> [root at r17init5 ~]# sg_inq -p 0x83 /dev/sdba
> VPD INQUIRY: Device Identification page
>   Designation descriptor number 1, descriptor length: 20
>     designator_type: NAA,  code_set: Binary
>     associated with the addressed logical unit
>       NAA 6, IEEE Company_id: 0x24a937
>       Vendor Specific Identifier: 0xfc048517
>       Vendor Specific Identifier Extension: 0x648240bb00010005
>       [0x624a9370fc048517648240bb00010005]
>   Designation descriptor number 2, descriptor length: 47
>     designator_type: T10 vendor identification,  code_set: ASCII
>     associated with the addressed logical unit
>       vendor id: PURE
>       vendor specific: FlashArray:FC048517648240BB00010005
>   Designation descriptor number 3, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Relative target port,  code_set: Binary
>     associated with the target port
>       Relative target port: 0x13
>   Designation descriptor number 4, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Target port group,  code_set: Binary
>     associated with the target port
>       Target port group: 0x0
>   Designation descriptor number 5, descriptor length: 8
>     designator_type: Logical unit group,  code_set: Binary
>     associated with the addressed logical unit
>       Logical unit group: 0x0
>   Designation descriptor number 6, descriptor length: 36
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: SCSI name string,  code_set: UTF-8
>     associated with the target port
>       SCSI name string:
>       naa.524a937000013312,t,0x0001
>   Designation descriptor number 7, descriptor length: 16
>     designator_type: vendor specific [0x0],  code_set: ASCII
>     associated with the addressed logical unit
>       vendor specific: validation4
>
> [root at r17init5 ~]# sg_inq -p 0x83 /dev/sde
> VPD INQUIRY: Device Identification page
>   Designation descriptor number 1, descriptor length: 20
>     designator_type: NAA,  code_set: Binary
>     associated with the addressed logical unit
>       NAA 6, IEEE Company_id: 0x24a937
>       Vendor Specific Identifier: 0xfc048517
>       Vendor Specific Identifier Extension: 0x648240bb00010003
>       [0x624a9370fc048517648240bb00010003]
>   Designation descriptor number 2, descriptor length: 47
>     designator_type: T10 vendor identification,  code_set: ASCII
>     associated with the addressed logical unit
>       vendor id: PURE
>       vendor specific: FlashArray:FC048517648240BB00010003
>   Designation descriptor number 3, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Relative target port,  code_set: Binary
>     associated with the target port
>       Relative target port: 0x7
>   Designation descriptor number 4, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Target port group,  code_set: Binary
>     associated with the target port
>       Target port group: 0x0
>   Designation descriptor number 5, descriptor length: 8
>     designator_type: Logical unit group,  code_set: Binary
>     associated with the addressed logical unit
>       Logical unit group: 0x0
>   Designation descriptor number 6, descriptor length: 36
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: SCSI name string,  code_set: UTF-8
>     associated with the target port
>       SCSI name string:
>       naa.524a937000013306,t,0x0001
>   Designation descriptor number 7, descriptor length: 16
>     designator_type: vendor specific [0x0],  code_set: ASCII
>     associated with the addressed logical unit
>       vendor specific: validation2
>
> [root at r17init5 ~]# sg_inq -p 0x83 /dev/sdt
> VPD INQUIRY: Device Identification page
>   Designation descriptor number 1, descriptor length: 20
>     designator_type: NAA,  code_set: Binary
>     associated with the addressed logical unit
>       NAA 6, IEEE Company_id: 0x24a937
>       Vendor Specific Identifier: 0xfc048517
>       Vendor Specific Identifier Extension: 0x648240bb00010003
>       [0x624a9370fc048517648240bb00010003]
>   Designation descriptor number 2, descriptor length: 47
>     designator_type: T10 vendor identification,  code_set: ASCII
>     associated with the addressed logical unit
>       vendor id: PURE
>       vendor specific: FlashArray:FC048517648240BB00010003
>   Designation descriptor number 3, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Relative target port,  code_set: Binary
>     associated with the target port
>       Relative target port: 0x3
>   Designation descriptor number 4, descriptor length: 8
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: Target port group,  code_set: Binary
>     associated with the target port
>       Target port group: 0x0
>   Designation descriptor number 5, descriptor length: 8
>     designator_type: Logical unit group,  code_set: Binary
>     associated with the addressed logical unit
>       Logical unit group: 0x0
>   Designation descriptor number 6, descriptor length: 36
>     transport: Fibre Channel Protocol for SCSI (FCP-2)
>     designator_type: SCSI name string,  code_set: UTF-8
>     associated with the target port
>       SCSI name string:
>       naa.524a937000013302,t,0x0001
>   Designation descriptor number 7, descriptor length: 16
>     designator_type: vendor specific [0x0],  code_set: ASCII
>     associated with the addressed logical unit
>       vendor specific: validation2
>
> So the first two have 0x624a9370fc048517648240bb00010005 and the second
> two have the 0x624a9370fc048517648240bb00010003. Is there some caching here
> that causes this? What could get us here?
>
> I have the server in the state currently so if there is any further output
> that would help figure out what happened here then let me know.
>
> Thanks,
> Brian
>
> Brian Bunker
> brian at purestorage.com
>
>
>
>
> --
> dm-devel mailing list
> dm-devel at redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>
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