Srik1920
2 Iron

what does IT mean in the "symdev list"out put

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E:\Program Files\EMC\SYMCLI\bin>symdev list -noport |more

Symmetrix ID:

        Device Name           Directors                  Device
--------------------------- ------------- -------------------------------------
                                                                           Cap
Sym  Physical               SA    DA :IT  Config        Attribute    Sts   (MB)
--------------------------- ------------- -------------------------------------

0053 Not Visible            ???:? 01A:D19 2-Way Mir     N/Grp'd      RW       3
0054 Not Visible            ???:? 16B:C18 2-Way Mir     N/Grp'd      RW       3
0055 Not Visible            ???:? 16A:D18 2-Way Mir     N/Grp'd      RW       3
0056 Not Visible            ???:? 01B:C15 2-Way Mir     N/Grp'd      RW       3
0073 Not Visible            ???:? 01A:D9  2-Way Mir     N/Grp'd      RW       3
0074 Not Visible            ???:? 16B:CC  2-Way Mir     N/Grp'd      RW       3
0075 Not Visible            ???:? 16A:DC  2-Way Mir     N/Grp'd      RW       3
0076 Not Visible            ???:? 01B:CD  2-Way Mir     N/Grp'd      RW       3
009B Not Visible            ???:? 16C:C1  2-Way Mir     N/Grp'd      RW       3

What does DA:IT mean in this ouput.I could figure that DA is disk director,what is IT?

Message was edited by: SymmetrixForumsModerator Removed Symmetrix ID.

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GTX1
1 Copper

Re: what does IT mean in the "symdev list"out put

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Every symmetrix director has 4 processors, Every processor has 2 ports namely (0/1 or C/D). drives are connected to these ports via fiber cables.

So for eg director 1 processor A, we have 2 ports namely 1A C port and 1A D port. the drives are connected to these ports using FC-AL technology, basically fiber channel loops, all drives are in a loop like a token ring network. thats is why ports are also called loops.Each drive carries an ALPA (Arbitrated Loop Physical address)value something simillar to wwn's.

ALso every port is controlled by 2 directors, the dual initiator, or the Rule 17 logic. So for director 1 the dual initiator is dir 16 (coz 1+16=17, called rule 17) so 1A  loops will also be controlled by 16A. But the 16A paths remain inactive, they will only become active if dir 1A fails.

ALPA addressing.png

Now Each DAE(Disk Array enclosure )in Symm has 15 drives configured.

So as said above following rule 17.

each DAE will associate with dirs either (1with 16 or 2 with 15 or 6 with 11 and 5 with 12)

Lets take an example of a DAE where C loop is configured on director 1 and 16..

So the drives are configured in such a way as eg: 01a will have drive C0 then 16a will C1, then 01a again takes drive C2 and 16a takes C3.. so it contnues..

DAE explained.bmp

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rajshekhar1
2 Bronze

Re: what does IT mean in the "symdev list"out put

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I think it stands for Interface

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dynamox
6 Thallium

Re: what does IT mean in the "symdev list"out put

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i believe it's interface

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Quincy561
4 Tellurium

Re: what does IT mean in the "symdev list"out put

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And T = Target. 

JohnToner1
2 Iron

Re: what does IT mean in the "symdev list"out put

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I is the interface and T is the TID.

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Srik1920
2 Iron

Re: what does IT mean in the "symdev list"out put

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All of you,

Thanks for reply.

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dynamox
6 Thallium

Re: what does IT mean in the "symdev list"out put

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John,

what does TID stand for ?

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Quincy561
4 Tellurium

Re: what does IT mean in the "symdev list"out put

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TID = Target ID AFAIK.

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A_J_
1 Copper

Re: what does IT mean in the "symdev list"out put

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Hi,

DA:IT refers to the drive location where your device is actually storing data on the symmetrix. IT means interface.

we have upto 16 directors on a symm. Not all will be DA directors, physical drives are accessed only by DA directors.

A drive location in a symmetirx is written in this format

Director - Processor(a,b,c,d) - Loop(Port 0/1 or C/D) - Loop interface

for a drive eg 01A:D19, 1 is the DA director, A is the processor or DA slice, D is the port or loop. 19 is the drive location on that port. therefore the drive is located on director 1A interface is D19 which means port 1 drive no. 19 on the port.

Please email me at anuj.goyal@emc.com if you have further queries on the same.

Srik1920
2 Iron

Re: what does IT mean in the "symdev list"out put

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Hi AJ,

Thanks for ur reply.But Aj can u please explain me how to identify disks in DMX.In clariion we

can identify by Busnumber,DAE number and disk number(BUS 0,DAE 1,DISK 5).In symmerix how to 

do this.If availble please explain using a picture.Also in your above explaination I could understand only upto

Director - Processor(a,b,c,d) ,I could not understand about  - Loop(Port 0/1 or C/D) - Loop interface.Because most of

the documents I read explained upto directors and 4 processor but I could not find explaination of backend

architechture between DA and disks In DAE in storage bay.Hope this ouput helps u in explaining it.

E:\Program Files\EMC\SYMCLI\bin>symdisk list -disk_group 1 |more

Symmetrix ID                 :

Disks Selected               : 216

Disk Group                   : 1

Disk Group Name              : DISK_GROUP_001

Technology                   : N/A

Speed (RPM)                  : 15000

                                                         Capacity(MB)

Ident  Symb Int TID Vendor     Type       Hypr   Total       Free      Actual

------ ---- --- --- ---------- ---------- ---- ---------- ---------- ----------

DF-1A  01A    C   0 SEAGATE    H146156      19     140014      12744     140014

DF-1A  01A    C   2 SEAGATE    H146156      19     140014      12744     140014

DF-1A  01A    C   4 SEAGATE    H146156      19     140014       6237     140014

DF-1A  01A    C   6 SEAGATE    H146156      19     140014       6237     140014

DF-1A  01A    C   8 SEAGATE    H146156      19     140014       6237     140014

DF-1A  01A    C   A SEAGATE    H146156      19     140014       6237     140014

DF-1A  01A    C   C SEAGATE    H146156      18     140014       9146     140014

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