Re: What partition should the MTMKPART argument specify? Was: Re: st driver doesn't seem to grok LTO partitioning

[Douglas Gilbert <dgilbert@interlog.com>]

Hi,
With a HP Ultrium 3000 tape drive (LTO-5) and a HP C7975A
tape cartridge (LTO-5 and partition capable) and mt as
patched by Shane:

# lsscsi -g
[1:0:0:0]  disk    ATA    ST3320620AS      K     /dev/sda   /dev/sg0
[6:0:0:0]  tape    HP     Ultrium 5-SCSI   Z64D  /dev/st0   /dev/sg1

# sg_read_attr -s 3 /dev/sg1
Partition number list:
   First partition number: 0
   Number of partitions available: 1

# mt -f /dev/st0 stsetoption debug
# mt -f /dev/st0 stsetoption can-partitions
# mt -f /dev/st0 mkpartition 10000

The following was cut and pasted from /var/log/messages

st 6:0:0:0: [st0] Block limits 1 - 16777215 bytes.
[st0] Mode sense. Length 11, medium 0, WBS 10, BLL 8
[st0] Density 58, tape length: 0, drv buffer: 1
[st0] Block size: 0, buffer size: 4096 (1 blocks).
[st0] Updating partition number in status.
[st0] Got tape pos. blk 0 part 0.
[st0] Loading tape.
[st0] Block limits 1 - 16777215 bytes.
[st0] Mode sense. Length 11, medium 0, WBS 10, BLL 8
[st0] Density 58, tape length: 0, drv buffer: 1
[st0] Block size: 0, buffer size: 4096 (1 blocks).
[st0] Partition page length is 12 bytes.
[st0] PP: max 1, add 0, xdp 1, psum 03, pofmetc 4, rec 03, units 09, sizes: 1529 0
[st0] MP: 11 0a 01 00 3c 03 09 00 05 f9 00 00
[st0] psd_cnt 2, max.parts 1, nbr_parts 0
[st0] Formatting tape with two partitions (1 = 10000 MB).
[st0] Sent partition page length is 12 bytes. needs_format: 1
[st0] PP: max 1, add 1, xdp 1, psum 03, pofmetc 4, rec 03, units 09, sizes: 65535 10
[st0] MP: 11 0a 01 01 3c 03 09 00 ff ff 00 0a
[st0] Sending FORMAT MEDIUM
[st0] Rewinding tape.

# sg_read_attr -s 3 /dev/sg1
Partition number list:
   First partition number: 0
   Number of partitions available: 2

Looks good.

Tested-by: Douglas Gilbert <dgilbert@interlog.com>


On 16-02-04 12:54 PM, "Kai Mäkisara (Kolumbus)" wrote:
>
>> On 4.2.2016, at 3.43, Seymour, Shane M <shane.seymour@hpe.com> wrote:
>>
>> Hi Kai,
>>
>> Tested with patched kernel 4.5.0-rc2-next-20160202+. It's looking good everything partition related passed with DDS5 and LTO6. You can definitely add me as a tested-by. I did find one issue below but it's not related to the partitioning changes.
>>
> Thanks for testing. It would be interesting to get confirmation from a LTO-5 user that partitioning
> works. Even without that I will make the final patch within a few days (remove some debugging
> and update the documentation).
>
> ...
>> I did find one issue in testing unrelated to the changes, the tell option didn't work with my LTO-6 drive:
>>
>> # ./mt -f /dev/st0 tell
>> /dev/st0: Input/output error
>>
>> [ 2045.974642] st 3:0:0:0: [st0] Block limits 1 - 16777215 bytes.
>> [ 2045.975221] st 3:0:0:0: [st0] Mode sense. Length 11, medium 0, WBS 10, BLL 8
>> [ 2045.975224] st 3:0:0:0: [st0] Density 5a, tape length: 0, drv buffer: 1
>> [ 2045.975226] st 3:0:0:0: [st0] Block size: 0, buffer size: 4096 (1 blocks).
>> [ 2045.975718] st 3:0:0:0: [st0] Error: 8000002, cmd: 34 1 0 0 0 0
>> [ 2045.975723] st 3:0:0:0: [st0] Sense Key : Illegal Request [current]
>> [ 2045.975726] st 3:0:0:0: [st0] Add. Sense: Invalid field in cdb
>> [ 2045.975729] st 3:0:0:0: [st0]  Can't read tape position.
>> [ 2045.975857] st 3:0:0:0: [st0] Rewinding tape.
>>
>> I believe that in get_location() we're doing this:
>>
>> static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
>>                         int logical)
>> {
>>         int result;
>>         unsigned char scmd[MAX_COMMAND_SIZE];
>>         struct st_request *SRpnt;
>>
>>         if (STp->ready != ST_READY)
>>                 return (-EIO);
>>
>>         memset(scmd, 0, MAX_COMMAND_SIZE);
>>         if ((STp->device)->scsi_level < SCSI_2) {
>>                 scmd[0] = QFA_REQUEST_BLOCK;
>>                 scmd[4] = 3;
>>         } else {
>>                 scmd[0] = READ_POSITION;
>>                 if (!logical && !STp->scsi2_logical)
>>                         scmd[1] = 1; <<<<<<<<<<<<<<
>>         }
>>
>> When called from the ioctl that the tell option uses the variable logical is passed in as 0 (from what I could see everything else sets it to 1). For a READ_POSITION the drive I'm using only supports 0, 6, or 8 in the service action field of the second byte:
>>
> I think you have not set the scsi2_logical option bit with mt or stinit or some other tool.
> The default of device-specific addresses is a historical mistake but we have to live with
> it. I don’t see this as a big problem because any user of current drives should enable
> some driver options anyway.
>
> Thanks,
> Kai
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html