求助：smc初级问题

zoneg

菜鸟，初接触itdt，现有带库TS3500，两个机械臂，据集成商说是全双工，均可访问全带库，用sudo ./itdt -f /dev/smcx inventory|more命令对smc0和smc1查看，发现robot address和Import/Export Station Address是一样的，但是driver address和slot address不完全相同，且相同address的内含的 Volume Tag却不同，有些迷惑，如何理解？

还有，我用 java -jar TS3500CLI.jar -a 192.168.x.x --viewLogicalLibraryDetails SYSTEM -u hpc -p xxxx命令查看分别查看各虚拟带库的信息，发现driver element address range和storage element address range都相差很近，比如1026~4278和1027~4279，但实际两个虚拟带库的assigned cartridges只有15和143个，这个range只是一个很粗的范围？

Sun_Up

I guess your TS3500 is partitioned to two logical libraies.

In the example below, you can see that smc0 and smc1 have the same a library serial number T0039 but the different 1st slot address 0403 on smc0 and 0402 on smc1, so smc0 and smc1 are the different logical library.

> itdt -f/dev/smc0 inquiry 80
Issuing inquiry for page 0x80...
Inquiry Page 0x80,  Length 20

            0 1  2 3  4 5  6 7  8 9  A B  C D  E F   0123456789ABCDEF
    0000 - 0880 0010 3030 3030 3030 3054 3030 3339  [...0000000T0039]
    0010 - 3034 3033                                                        [0403            ]



Exit with code: 0
> itdt -f/dev/smc1 inquiry 80
Issuing inquiry for page 0x80...
Inquiry Page 0x80,  Length 20

            0 1  2 3  4 5  6 7  8 9  A B  C D  E F   0123456789ABCDEF
    0000 - 0880 0010 3030 3030 3030 3054 3030 3339  [...0000000T0039]
    0010 - 3034 3032                                                        [0402            ]



Exit with code: 0

zoneg

继续请教：smc可以固定分派给不同的逻辑带库？而实际上我这里是分了4个逻辑带库，其中一个逻辑带库给TSM进行管理,做了多路径，通过命令查看信息，smc0、2、4、6的各种信息一样，smc1、3、5、7的一样：
# sudo ./itdt -f /dev/smc6 inquiry 80
……
    0000 - 0880 0010 3030 3030 3037 3832 3433 3038  [...000007824308]
    0010 - 3034 3031                                [0401            ]
*********************
# sudo ./itdt -f /dev/smc7 inquiry 80
……
    0000 - 0880 0010 3030 3030 3037 3832 3433 3038  [...000007824308]
    0010 - 3034 3032                                [0402            ]
他们的serial number一样，那他们是同一个机械臂吗？
我想知道的是，为何smc1和smc2的slot address不完全一样，即使地址一样的，对应的volume tag又不一样，是说address不是全局的？smc+address才能唯一确定一个slot？

zoneg

回复 2# Sun_Up


    smc到底该怎么理解啊……

无牙

AIX下的机械手

zoneg

回复 5# 无牙


    我知道是机械手，但是查两个机械手的inventory信息不一致，address在带库中是唯一的吗？为什么两个smc的slot信息里同一个ddress却对应不同的volume tag

Sun_Up

It is easy to understand if you assume the two logical libraries as two streets in same an area. For example, the street 1 can has the addresses 1,2,3,4,5, the Street 2 can has the addresses 2,3,4,5,6. The address assigment isn't same at the two streets. Even for the same address 2, the person (volume tag) who lives in the house at street 1 is different than that one (volume tag) in the house at street 2.

For TS3500, Advanced Library Management System (ALMS) is enable by default. With the Advanced Library Management System (ALMS) enabled in the TS3500
Tape Library, each storage element address is no longer associated with a specific storage slot. Instead, storage slots are virtualized by dynamically associating
element addresses to them, as required. An element address is associated with a storage slot that is selected by the library as cartridges are moved and inventoried.
In the case of a storage element that is empty due to a move, that source element address will be unassociated. Association of storage element addresses is
accomplished in a way that is completely transparent to the application software.

With ALMS enabled, the first storage element address of any logical library is equal to 1024 plus the logical library number. For example in your case, logical library smc6 and smc7 will
have the starting storage element addresses of 1025 (X’401’) and 1026(X'402').

To learn more on ALMS, refer to the document "IBM System Storage TS3500 Tape Library with ALMS  -- Introduction and Planning Guide"
http://publib.boulder.ibm.com/in ... oc/GA32-0593-03.pdf

zoneg

回复 7# Sun_Up
非常感谢
还有点疑惑：我的smc1、3、5、7的信息是一样的，smc0、2、4、6是一样的，我现在可以确认smc0是逻辑带库1的control path，smc1是逻辑带库2的，但是我还有两个逻辑带库找不到对应的control path，/dev下倒是还有smc8、9、10、11四个设备文件，但是用itdt查询都报IO error，我想知道这四个逻辑带库的control path与物理上的两个机械手是如何对应的？

还有，control path是啥意思？就是指设备文件名吗？比如smc和rmt？
谢谢

Sun_Up

Run the command to show how any control path is in the library. In my example, you can see that smc0 and smc2 are same in a logical library. It means the logical library has two control pathes.

> ./itdt -f /dev/smc0 qrypath
Querying SCSI paths...
Total paths configured........... 2

Primary Path Number 1
  Logical Device................. smc0
  Product Identification......... 03584L22
  Serial Number.................. 0000000T0039040
  Host Bus Adapter............... fscsi0
  Dynamic Tracking Enabled....... Yes
  SCSI Channel................... 0
  FCP SCSI ID.................... 0x611400
  FCP Logical Unit............... 0x1000000000000
  FCP World Wide Port Name....... 0x500507630099f011
  FCP World Wide Node Name....... 0x500507630019f011
  Path Enabled................... Yes
  Path Manually Disabled......... No

Alternate Path Number 2
  Logical Device................. smc2
  Product Identification......... 03584L22
  Serial Number.................. 0000000T0039040
  Host Bus Adapter............... fscsi0
  Dynamic Tracking Enabled....... Yes
  SCSI Channel................... 0
  FCP SCSI ID.................... 0x6119b1
  FCP Logical Unit............... 0x1000000000000
  FCP World Wide Port Name....... 0x500507630059f011
  FCP World Wide Node Name....... 0x500507630019f011
  Path Enabled................... Yes
  Path Manually Disabled......... No


Exit with code: 0

What is the control path? A tape drive in library can own Lun 0 (data path (rmt) for read and write and other I/O for tape) and Lun 1 (control path (smc) to manage tape library). Usually, only a control path is enable for a logical library. To setup the mutliple control path for a logical library, you must enable the control path (Lun 1) on other tape drive via the web Gui or operate panel of the library.  In the tapeutil command, it shows the control path for smc0 and smc2 is from rmt1 and rmt3.


> tapeutil -f /dev/smc0 path
Querying device paths...

Primary Path Number 1
  Logical Device................. smc0
  Product Identification......... 03584L22
  Serial Number.................. 0000000T00390403
  Control Path Drive............. rmt1              <----
  SCSI Parent.................... fscsi0
  Dynamic Tracking Enabled....... Yes
  FCP SCSI ID.................... 0x611400
  FCP Logical Unit............... 0x1000000000000
  FCP World Wide Port Name....... 0x500507630099f011
  FCP World Wide Node Name....... 0x500507630019f011
  Path Enabled................... Yes
  Path Manually Disabled......... No

Alternate Path Number 2
  Logical Device................. smc2
  Product Identification......... 03584L22
  Serial Number.................. 0000000T00390403
  Control Path Drive............. rmt3  
  SCSI Parent.................... fscsi0
  Dynamic Tracking Enabled....... Yes
  FCP SCSI ID.................... 0x6119b1
  FCP Logical Unit............... 0x1000000000000
  FCP World Wide Port Name....... 0x500507630059f011
  FCP World Wide Node Name....... 0x500507630019f011
  Path Enabled................... Yes
  Path Manually Disabled......... No

Current path..................... 1
Total paths configured........... 2

A smc device is a medium changer which manages the robots, I/O slots, Storage Slots and tape drives in the logical library, and not just a robot.

The robots in a physical library are shared for all of the logical libraries.

I guess smc8, 9, 10,11 aren't configured and are in define state. What is the output of lsdev -Cc tape?

In your case, "smc1、3、5、7的信息是一样的，smc0、2、4、6是一样的". Your physical library is partitioned to two logical libraries and each logical library has 4 control pathes.

zoneg

终于接近真相了，豁然开朗，非常感谢大牛！既然robot可以在逻辑带库之间共享，那对两个robot，可以自动负载均衡吗？我一共四个逻辑带库，smc0~7是前两个逻辑带库的control path，我是否需要把任务分派到每一个control path上，才能最大可能的做到负载均衡？还是多control path只是用来做备份而已？对我这里俩robot，该怎样用才能价值最大化？对每个带库都只用primary control path的话，带库可以自动分派给两个robot？