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Zoning of tape drives with Media Server

Narrybhatia
Level 4

Hi, 

I have 4 Media servers and I want to zone my 13 tape drives with those media servers in SSO environment. Can anyone please guide me step by step procedusre to follow?

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sdo
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Initial thoughts in the spreadsheet attached.

.

Notes:

N1) Some servers have to serve four tape drives.  If the media servers have not been sized/scoped properly, they might not be able to actually achieve that.

N2) If a server was lost, then are the remaining three servers even capable of efficiently serving the additional tape drives.

N3) AFAIK, multi-pathing of tape is still not supported - so, a question to ask oneself is:   How does one manage re-configuring either zoning and/or opening ports and re-discovering tape drives in the event of any of these circumstances:

- loss of entire fabric

- loss of one server

- loss of one path to one tape drive

...what I'm trying to do... is get you thinking... what you will see below is that we implement all required zones, but because we persistently disable one of the SAN switch ports facing each of the tape drives, then this effectively manages the 'visibility' and thus actual usage of teh tape drives.

N4) Personally, I would implement all the zoning to support what might appear to be multi-pathing, but - N.B: - keep one of the paths to each tape drive down at all normal times by persistently disabling the SAN switch port facing the tape drive port which is not normally used.

N5) You will control which tape drive ports are visible by either persistently enabling or persistently disabling specific SAN switch ports that face tape drives.  You will NOT be controlling which tape drive ports/paths are visible by enabling/disabling the SAN switch ports facing the media servers.

N6) This initial thinking assumes that the Quantum i6000 IOSB modules will not be used as a kind of fencing gateway to tape paths.  If you do want to control tape drive 'visibility' from the Quantum i6000 itself then all my thinking in this first round is shot to pieces.

N7) In the spreadsheet you will see a couple of 'blue' names/zones - these are the ones that were manually moved to balance the distribution of tape drives.

N8) It's still not clear what models the tape drives are, thus... it may yet transpire that you simply do not have enough media server ports to fully serve 3, let alone 4, tape drives from any given media server.

.

Spreadsheet is here:   vvvVVVvvv

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13 REPLIES 13

sdo
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1) Are the media servers something uber nice like Sun M5000 or higher?   (Anything less than that and they will each be very unlikely to be able to drive all 13 tape drives.)

2) Are all 13 tape drives in one robot?

3) All at one site?

4) Is the master server also FC attached?  (because we might want to make this a robot control host - if if's not clustered)   remember - if the robot control host goes down, then all tape drives will cease to work.   Or are you using an ACLS library?

5) Is the master server clustered?

6) 13 tape drives seems a very 'specific' number.  Are you able to describe how you arrived at this number?

7) Do your tape drives need to be resilient for N+1 media servers or for N+2 media servers (more complex).

8) How many SAN switching fabrics?

9) N.B:  >>> **** I wish I could wave a flag here... and shout!!    Hey!!  Ever heard of "cut through routing"?  **** <<<   If you haven't heard of this term before, then search this forum... because... before you create a zoning plan... you have a wonderful opportunity to get your FC SAN cabling spot on... for uber maximum benefit !!        If you can tell me SAN your switch model and how many spare ports you have on each switch - then I can help you structure your SAN fibre cabling to achieve zero latency (well ok, not quite zero, but something like 2 nano-second latency) on your links between media server HBA ports and tape drives.

10) Are the tape drives dual ported?

.

I would suggest balancing the tape drives, such that each of the four media servers has six or seven tape drives, i..e the loss of any one media server will mean that all tape drives are still usable - i.e. an N+1 environment.

Some zoning tips:

i) All zones for tape need to be single initiator, single target - no ifs, no buts, no maybes - and I don't care what anyone else says, because they're definitely wrong.  N.B:  Tape is always single initiator, single target.

That's it for the tips.

.

Answer the questions above - and I may be able to help you with a cabling map and a zoning plan.  If you want.

Narrybhatia
Level 4

HI Sdo,

 

Thank you for your valuable tips . Here is some information I have:

 

1) Are the media servers something uber nice like Sun M5000 or higher?   (Anything less than that and they will each be very unlikely to be able to drive all 13 tape drives.)

Media Servers are typical Windows Servers 2008 R2

2) Are all 13 tape drives in one robot?

Yes..all tape drives are in one Robot

3) All at one site?

Yes..All are onsite

4) Is the master server also FC attached?  (because we might want to make this a robot control host - if if's not clustered)   remember - if the robot control host goes down, then all tape drives will cease to work.   Or are you using an ACLS library?

Master Server is FC attached

5) Is the master server clustered?

Yes , Master Server is Clustered

6) 13 tape drives seems a very 'specific' number.  Are you able to describe how you arrived at this number?

Tape drives are numbered from SCSI.000 - SCSI.012

7) Do your tape drives need to be resilient for N+1 media servers or for N+2 media servers (more complex).

N+1 Media Server

I have no information about SAN switch part as of now. I want atleast two Media servers to be zoned with each drive so that if one media server goes down then another media server runs the drive.

 

Douglas_A
Level 6
Partner Accredited Certified

Sdos info is good.. 

 

Simply zone the tape drives to all the media servers.. pick one for the robot controller and another for a failover.. 

 

once zoning is completed run the drive configuration wizard and it will discover all the drives and discover they are all on the same robot, you will end up seeing all 13 drives and one robot once configured and NBU will decide which host to make the scan host/control host for each drive. Once that is done you should be able to create a STU that allows access to all drives from any one of the hosts. 

Nicolai
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I am with this one also :

All zones for tape need to be single initiator, single target - no ifs, no buts, no maybes - and I don't care what anyone else says, because they're definitely wrong.  N.B:  Tape is always single initiator, single target

One tape drive, one zone, one fibre channel HBA.

Just remeber a fibre channel HBA (initiator) can be a member of many zones

mph999
Level 6
Employee Accredited

I would also suggest, as SDO, not zoning all 13 drives to each server, they cannot use that many at once.

A physical drive needs a throughput of something like 90 MB/s to stream (less if not compressed, more if 2:1 comprssed)

Can your media server push 1170 MB/s to the drives at the same time ?

No, probably not ...

In which case, work out how much data cnan be pushed through the HBA cards, and zone that many drives.

EG. If you had a 2 gig HBA port, that has a max throughput of about 200 MB/s, so that would support a maximum of x2 LTO 5 drives.  You also need to consider how much data the 'backplane' of the media server can transfer.

sdo
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8) How many fabrics?

9) How many HBA ports (not HBA cards) are available in each of the four media servers?

10) Are the tape drives dual ported?

11) Make and model of SAN switches?

12) Robot make and model?

13) Are the tape drives to be direct attached to the SAN switches - *OR* - are they obfuscated/serial-spoofed behind a module (e.g. something like an IOSB in Quantum i6000)?

.

Then we can work out a cabling map.

Then we can work out a zoning plan.

BTW Q13 above is an important question.  Cabling and zoning is impossible to get right if the answer to Q13 is not known. 

Narrybhatia
Level 4

8) How many fabrics?

Two for each Media Server

9) How many HBA ports (not HBA cards) are available in each of the four media servers?

Two HBA ports on each Media Server

10) Are the tape drives dual ported?

Yes..drives are dual ported

3) Are the tape drives to be direct attached to the SAN switches - *OR* - are they obfuscated/serial-spoofed behind a module (e.g. something like an IOSB in Quantum i6000)?

Drives are connected to the Quamtum i6000 tape library through 8Gb FC.

 

Please let me know any other information is required.

sdo
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6) Sorry, I meant how did you arrive at the conclusion that 13 tape drives are required?

11) SAN switch models?   Some vendors support cut-through routing as default (but big/dense blades still need consideration) - some vendors do not support cut through routing.  What model are your SAN switches?  I hope it is Brocade.

13) Ok - even though your tape drives are dual ported - this doesn't necessarily either rule-in or rule-out the use of an IOSB quasi-blade in the i6000.   We really need to find out if you are using an IOSB to hide/manage/present-out only one of the ports from each tape drive.  Can you find out whether your library includes IOSBs, and if so how many?

14) How did you arrive at the conclusion tha 4 media server are required?

15) What model are the tape drives?

16) Are all tape drives the same model?  If not, please clarify counts of model types?

sdo
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Ok - here's some tips:

T1) Keep the physical side of things simple, e.g. cable all first ports (usually port 0) to fabric A.     And cable all second ports (usually port 1) to fabric B.

T2) Do not leave SAN switch ports in auto-negotiate 'N8' mode.  Instead set all used ports to fixed speed 8Gb.

T3) Persistently disable all unused ports.

.

Ok - Narry... I'm now going to share with you my initial thinking - and anyone else watching, please feel free to jump in and offer any advice or raise any questions - don't be shy - we won't bite - any additional input/thinking/suggestions/advice/experience/questions/issues/problems/opportunities is always appreciated.

Caveat - Narry, please take this with a pinch of salt... only because I'm sitting here blind with no knowledge of your requirements or design, and anything I offer is only a scenario.  There is no one single way to do this.  There are many solutions to your question - and this is only the first draft.  Think of it as an example to assit in steering your thinking.  Do NOT take anything I post as "the solution", what I offer is not meant that way... and because we still have some un-answered questions - then all is still open to change, and possibly quite radically too.

sdo
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Initial thoughts in the spreadsheet attached.

.

Notes:

N1) Some servers have to serve four tape drives.  If the media servers have not been sized/scoped properly, they might not be able to actually achieve that.

N2) If a server was lost, then are the remaining three servers even capable of efficiently serving the additional tape drives.

N3) AFAIK, multi-pathing of tape is still not supported - so, a question to ask oneself is:   How does one manage re-configuring either zoning and/or opening ports and re-discovering tape drives in the event of any of these circumstances:

- loss of entire fabric

- loss of one server

- loss of one path to one tape drive

...what I'm trying to do... is get you thinking... what you will see below is that we implement all required zones, but because we persistently disable one of the SAN switch ports facing each of the tape drives, then this effectively manages the 'visibility' and thus actual usage of teh tape drives.

N4) Personally, I would implement all the zoning to support what might appear to be multi-pathing, but - N.B: - keep one of the paths to each tape drive down at all normal times by persistently disabling the SAN switch port facing the tape drive port which is not normally used.

N5) You will control which tape drive ports are visible by either persistently enabling or persistently disabling specific SAN switch ports that face tape drives.  You will NOT be controlling which tape drive ports/paths are visible by enabling/disabling the SAN switch ports facing the media servers.

N6) This initial thinking assumes that the Quantum i6000 IOSB modules will not be used as a kind of fencing gateway to tape paths.  If you do want to control tape drive 'visibility' from the Quantum i6000 itself then all my thinking in this first round is shot to pieces.

N7) In the spreadsheet you will see a couple of 'blue' names/zones - these are the ones that were manually moved to balance the distribution of tape drives.

N8) It's still not clear what models the tape drives are, thus... it may yet transpire that you simply do not have enough media server ports to fully serve 3, let alone 4, tape drives from any given media server.

.

Spreadsheet is here:   vvvVVVvvv

sdo
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N9) In the sreadsheet use the filter at the top of column D to view just one fabric.

N10) The top section of the sheet in column H, contains a countif crosscheck to detect if a WWPN appears in the list more than once.

N11) I haven't yet marked the SAN switch ports which need to be persistently disabled to avoid multi-pathing... i.e. some SAN switch ports in fabric A, and also some in fabric B, will need to be persistently disabled - so that fabric A carries about half of the workload, and so that fabric B carries about half of the workload.  But we can add that later if and when you are able to answer the remaining as yet unanswered questions.

N12) What you will see/find, is that seven tape drives are via fabric A, and six tape drives are via fabric B.

sdo
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N13) A word of caution:  (and I hope it's not negatively auspiscious that this is note number 13!)... The physical cabling decision is still very unresolved.  We need to determine exact SAN fibre switch models, because this can have a massive impact on cabling and port layout.  The terms to research are "port groups" and "over-subscription".  Until you can verify the models I would consider the physical cabling very much as pie in the sky.

sdo
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Narry - no feed back?