Advanced Technical Skills (ATS) North America€¦ · SAN1 SAN2 SVC node1 SVC node2 Power Server...
Transcript of Advanced Technical Skills (ATS) North America€¦ · SAN1 SAN2 SVC node1 SVC node2 Power Server...
Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
Overview
Dan Braden and Bill WiegandIBM Advanced Technical SkillsMay 29, 2012
Dienstag, 29. Mai 12
Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation2
Dienstag, 29. Mai 12
Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
Power VIO and SVC Disk Path Design
Dan Braden – IBM Power ATSBill Wiegand – IBM Storage ATS
December 14, 2011
Dienstag, 29. Mai 12
Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
Agenda
Determine and examine all possible 4 path designs Dual VIOS, dual SAN fabric and SVC Examine each for availability characteristics
Handling multiple VIOCsExtend to more SVC IO groupsIncreasing bandwidth
Dienstag, 29. Mai 12
Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
Objective
The objective of this presentation is to show alternative disk path designs to setup a dual VIOS environment with SVC storage, and their availability characteristics.
This will examine zoning with 4 vFCs, each connected to a single SVC port to generate 4 paths/LUN.
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Advanced Technical Skills (ATS) North America
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Definitions
SAN link – a cable connecting a storage port to the SAN or a server port to the SAN Disk path – a logical path from a specific host port to a specific storage port WWPN – World Wide Port Name – unique 16 digit ID for a host or storage port Active/passive disk subsystem – a disk subsystem with dual controller/processors
where a controller handles all IOs for a LUN except under failure scenarios Half the LUNs are typically owned by each controller to use all resources
VIOS – Virtual IO Server VIOC – Virtual IO Client vFC – Virtual Fibre Channel adapter created with VIO for a VIOC
Tied to a specific real FC adapter in a VIOS Has an online and offline WWPN to facilitate LPM The active WWPN changes with each LPM
LPM – Live Partition Mobility – the ability to move a running VIOC LPAR from one Power system to another Requires all IO for the VIOC to be virtualized thru VIOSs
WWPN zone: Typically a single initiator (host port) zone indicating which storage ports with which the host port may communicate: host port WWPN, storage port WWPN, storage port WWPN, ….
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Zoning nomenclature
Single initiator zone – a zone with one host port, and one or more storage ports A best practice
Alias – Used to give a descriptive name to WWPNs Samples:
vFC0_myhost – the first virtual adapter port on the myhost LPARLPARa_fcs0 - fcs0 on a LPAR representing a host portN1_P3 – SVC Node 1 Port 3
This presentation assumes WWPN zoning
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Availability Requirements
We’d like to setup the zoning such that we can survive a double failure Failure of two of : VIOS, SAN fabric or SVC node
But not failure of both VIOSs, both SAN fabrics or both SVC nodes which will always cause an outage
With 2 ports per VIOS or SVC node, we can ignore failure of individual ports Two ports failing in a VIOS or SVC is equivalent to the VIOS/SVC failing
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Why 4 paths?
Minimizing the number of paths minimizes the time needed by AIX to determine paths have failed and to recover AIX must distinguish between a slow IO and a path failure
We don’t want to mark paths as failed if the IO is just slow
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© 2012 IBM Corporation
VIOC
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
Power Server
server port 1
server port 4
SVC IO Group
N1P1Node 1 Port 1
Assumes 2 host ports per VIOSAdditional ports can be used for additional bandwidth
One may create up to 4 vFCs here per VIOC
Availble host HBAs have 1, 2 or 4 ports
Each SVC node has 4 ports
SAN cabling
N2P3Node 2 Port 3
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Given 4 host ports and 4 storage ports we have 16 potential paths Paths reduced by half due to dual SAN fabric Can be further reduced by SAN zoning at the switch Can be further reduced by LUN masking at the SVC
A LUN served from the SVC is served from one IO group only Connections to other IO groups do not increase the number of paths
Options for 4 paths: 4 vFCs each connected to a different storage port 2 vFCs each connected to two storage ports
Doesn’t meet availability requirements as each vFC only uses one SAN fabric, so failure of a SAN fabric and the real adapter the other vFC uses causes an outage
1 vFC connected to 4 storage portsDoesn’t meet availability requirements as this can only use one SAN fabric
Thus we’ll use sets of ports that include 4 unique host ports and 4 unique storage ports
We’ll examine all the possible ways to use 4 vFCs connected to 4 storage ports
Skip to slide 28 to see designs meeting the requirement Or go thru them to understand what designs to avoid and why
How do we get 4 paths?
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Given 4 host ports and 4 storage ports, with one host port connected to one storge port, there are 24 ways to pair up the ports 4!=24 Not all can use all 4 storage ports Many are equivalent
How many ways are there to set this up?
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 11 11 11 11 11 11 11 11 11 11 11 11 12 12 12 12 12 12 12 12 12 12 12 1211 11 12 12 12 12 11 11 12 12 12 12 11 11 11 11 12 12 11 11 11 11 12 1222 22 21 22 21 22 22 22 21 22 21 22 21 22 21 22 21 21 21 22 21 22 21 2122 22 22 21 22 21 22 22 22 21 22 21 22 21 22 21 21 21 22 21 22 21 21 21
Table entries are VIOS#, SVC node#
Design#
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 11 11 11 11 11 11 12 12 12 12 12 12 13 13 13 13 13 13 14 14 14 14 14 1422 22 23 23 24 24 21 21 23 23 24 24 21 21 22 22 24 24 21 21 22 22 23 2333 34 32 34 32 33 33 34 31 34 31 33 32 34 31 34 31 32 32 33 31 33 31 3244 43 44 42 43 32 44 43 44 41 43 41 44 42 44 41 42 41 43 42 43 41 42 41
Design#
Table entries are host port#, storage port#
Since there’s no difference between ports on a VIOS, or ports on a SVC node, we can redo the table showing VIOS# and SVC node# for the ports
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How many ways are there to set this up?
Examining each design for unique ones, and reducing the design name to (SVCN#, SVCN#, SVCN#, SVCN#) for connection to VIOS1, VIOS1, VIOS2, VIOS2 respectively yields these 6 designs:
1. 1122 2. 12123. 12214. 21125. 21216. 2211
VIOS1 port 1Connected to
VIOS1 port 2Connected to
VIOS2 port1Connected to
VIOS2 port2Connected to
Design SVCN# SVCN# SVCN# SVCN#
1 1 1 2 2
2 1 2 1 2
3 1 2 2 1
4 2 1 1 2
5 2 1 2 1
6 2 2 1 1
Or simply:
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Advanced Technical Skills (ATS) North America
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LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N1P1Zone2: vFC1 WWPN2, N1P1Zone3: vFC2 WWPN1, N1P3 Zone4: vFC2 WWPN2, N1P3Zone5: vFC3 WWPN1, N2P1Zone6: vFC3 WWPN2, N2P1Zone7: vFC4 WWPN1, N2P3Zone8: vFC4 WWPN2, N2P3 Italic zones are for inactive WWPNs
Design 1 with 4 paths/LUN - 1122
vFC2
vFC3
vFC4
Disk PathsvFC1 - N1P1vFC2 – N1P3vFC3 – N2P1vFC4 – N2P3
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Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N1P1Zone2: vFC1 WWPN2, N1P1Zone3: vFC2 WWPN1, N1P3 Zone4: vFC2 WWPN2, N1P3Zone5: vFC3 WWPN1, N2P1Zone6: vFC3 WWPN2, N2P1Zone7: vFC4 WWPN1, N2P3Zone8: vFC4 WWPN2, N2P3 Italic zones are for inactive WWPNs
Design 1 with 4 paths/LUN VIOS failure
vFC2
vFC3
vFC4
Disk PathsvFC1 - N1P1vFC2 – N1P3vFC3 – N2P1vFC4 – N2P3
Lost zones and paths shown in red
Failure of SVC node2 results in an outage
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Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N1PxZone2: vFC1 WWPN2, N1PxZone3: vFC2 WWPN1, N2Px Zone4: vFC2 WWPN2, N2PxZone5: vFC3 WWPN1, N1PxZone6: vFC3 WWPN2, N1PxZone7: vFC4 WWPN1, N2PxZone8: vFC4 WWPN2, N2Px Italic zones are for inactive WWPNs
Design 2 with 4 paths/LUN - 1212
vFC2
vFC3
vFC4
Disk PathsvFC1 - N1PxvFC2 – N2PxvFC3 – N1PxvFC4 – N2Px
Not possible to zone this to use all storage ports
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SAN zoningZone1: vFC1 WWPN1, N1P1Zone2: vFC1 WWPN2, N1P1Zone3: vFC2 WWPN1, N2P3 Zone4: vFC2 WWPN2, N2P3Zone5: vFC3 WWPN1, N2P1Zone6: vFC3 WWPN2, N2P1Zone7: vFC4 WWPN1, N1P3Zone8: vFC4 WWPN2, N1P3 Italic zones are for inactive WWPNs
Design 3 with 4 paths/LUN - 1221
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO GroupvFC
2vFC
3vFC
4
Disk PathsvFC1 - N1P1vFC2 – N2P3vFC3 – N2P1vFC4 – N1P3
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Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N1P1Zone2: vFC1 WWPN2, N1P1Zone3: vFC2 WWPN1, N2P3 Zone4: vFC2 WWPN2, N2P3Zone5: vFC3 WWPN1, N2P1Zone6: vFC3 WWPN2, N2P1Zone7: vFC4 WWPN1, N1P3Zone8: vFC4 WWPN2, N1P3 Italic zones are for inactive WWPNs
Design 3 with 4 paths/LUN – VIOS failure
vFC2
vFC3
vFC4
Disk PathsvFC1 - N1P1vFC2 – N2P3vFC3 – N2P1vFC4 – N1P3
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Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N1P1Zone2: vFC1 WWPN2, N1P1Zone3: vFC2 WWPN1, N2P3 Zone4: vFC2 WWPN2, N2P3Zone5: vFC3 WWPN1, N2P1Zone6: vFC3 WWPN2, N2P1Zone7: vFC4 WWPN1, N1P3Zone8: vFC4 WWPN2, N1P3 Italic zones are for inactive WWPNs
Design 3 with 4 paths/LUN – SAN fabric failure
vFC2
vFC3
vFC4
Disk PathsvFC1 - N1P1vFC2 – N2P3vFC3 – N2P1vFC4 – N1P3
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Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N1P1Zone2: vFC1 WWPN2, N1P1Zone3: vFC2 WWPN1, N2P3 Zone4: vFC2 WWPN2, N2P3Zone5: vFC3 WWPN1, N2P1Zone6: vFC3 WWPN2, N2P1Zone7: vFC4 WWPN1, N1P3Zone8: vFC4 WWPN2, N1P3 Italic zones are for inactive WWPNs
Design 3 with 4 paths/LUN – SVC node failure
vFC2
vFC3
vFC4
Disk PathsvFC1 - N1P1vFC2 – N2P3vFC3 – N2P1vFC4 – N1P3
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LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N2P1Zone2: vFC1 WWPN2, N2P1Zone3: vFC2 WWPN1, N1P3Zone4: vFC2 WWPN2, N1P3Zone5: vFC3 WWPN1, N1P1Zone6: vFC3 WWPN2, N1P1Zone7: vFC4 WWPN1, N2P3Zone8: vFC4 WWPN2, N2P3 Italic zones are for inactive WWPNs
Design 4 with 4 paths/LUN - 2112
vFC2
vFC3
vFC4
Disk PathsvFC1 – N2P1vFC2 – N1P3vFC3 – N1P1vFC4 – N2P3
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Advanced Technical Skills (ATS) North America
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LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N2P1Zone2: vFC1 WWPN2, N2P1Zone3: vFC2 WWPN1, N1P3Zone4: vFC2 WWPN2, N1P3Zone5: vFC3 WWPN1, N1P1Zone6: vFC3 WWPN2, N1P1Zone7: vFC4 WWPN1, N2P3Zone8: vFC4 WWPN2, N2P3 Italic zones are for inactive WWPNs
Design 4 with 4 paths/LUN – VIOS failure
vFC2
vFC3
vFC4
Disk PathsvFC1 – N2P1vFC2 – N1P3vFC3 – N1P1vFC4 – N2P3
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Advanced Technical Skills (ATS) North America
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LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N2P1Zone2: vFC1 WWPN2, N2P1Zone3: vFC2 WWPN1, N1P3Zone4: vFC2 WWPN2, N1P3Zone5: vFC3 WWPN1, N1P1Zone6: vFC3 WWPN2, N1P1Zone7: vFC4 WWPN1, N2P3Zone8: vFC4 WWPN2, N2P3 Italic zones are for inactive WWPNs
Design 4 with 4 paths/LUN – SAN fabric failure
vFC2
vFC3
vFC4
Disk PathsvFC1 – N2P1vFC2 – N1P3vFC3 – N1P1vFC4 – N2P3
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Advanced Technical Skills (ATS) North America
© 2012 IBM Corporation
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N2P1Zone2: vFC1 WWPN2, N2P1Zone3: vFC2 WWPN1, N1P3Zone4: vFC2 WWPN2, N1P3Zone5: vFC3 WWPN1, N1P1Zone6: vFC3 WWPN2, N1P1Zone7: vFC4 WWPN1, N2P3Zone8: vFC4 WWPN2, N2P3 Italic zones are for inactive WWPNs
Design 4 with 4 paths/LUN – SVC node failure
vFC2
vFC3
vFC4
Disk PathsvFC1 – N2P1vFC2 – N1P3vFC3 – N1P1vFC4 – N2P3
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Advanced Technical Skills (ATS) North America
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LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N2PxZone2: vFC1 WWPN2, N2PxZone3: vFC2 WWPN1, N1PxZone4: vFC2 WWPN2, N1PxZone5: vFC3 WWPN1, N2PxZone6: vFC3 WWPN2, N2PxZone7: vFC4 WWPN1, N1PxZone8: vFC4 WWPN2, N1Px Italic zones are for inactive WWPNs
Design 5 with 4 paths/LUN - 2121
vFC2
vFC3
vFC4
Disk PathsvFC1 – N2PxvFC2 – N1PxvFC3 – N2PxvFC4 – N1Px
Not possible to zone this to use all storage ports
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Advanced Technical Skills (ATS) North America
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LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N2P1Zone2: vFC1 WWPN2, N2P1Zone3: vFC2 WWPN1, N2P3Zone4: vFC2 WWPN2, N2P3Zone5: vFC3 WWPN1, N1P1Zone6: vFC3 WWPN2, N1P1Zone7: vFC4 WWPN1, N1P3Zone8: vFC4 WWPN2, N1P3 Italic zones are for inactive WWPNs
Design 6 with 4 paths/LUN
vFC2
vFC3
vFC4
Disk PathsvFC1 – N2P1vFC2 – N2P3vFC3 – N1P1vFC4 – N1P3
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LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
SAN zoningZone1: vFC1 WWPN1, N2P1Zone2: vFC1 WWPN2, N2P1Zone3: vFC2 WWPN1, N2P3Zone4: vFC2 WWPN2, N2P3Zone5: vFC3 WWPN1, N1P1Zone6: vFC3 WWPN2, N1P1Zone7: vFC4 WWPN1, N1P3Zone8: vFC4 WWPN2, N1P3 Italic zones are for inactive WWPNs
Design 6 with 4 paths/LUN – VIOS failure
vFC2
vFC3
vFC4
Disk PathsvFC1 – N2P1vFC2 – N2P3vFC3 – N1P1vFC4 – N1P3
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Only designs 3 and 4 provide availability in case of a double failure There are inferior ways to zone
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
vFC2
vFC3
vFC4
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
vFC2
vFC3
vFC4
Design 3 Design 4
Designs meeting availability requirements
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Advanced Technical Skills (ATS) North America
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Designs meeting availability requirements
VIOS1 port 1Connected to
VIOS1 port 2Connected to
VIOS2 port1Connected to
VIOS2 port2Connected to
Design SVCN# SVCN# SVCN# SVCN#
1 1 1 2 2
2 1 2 1 2
3 1 2 2 1
4 2 1 1 2
5 2 1 2 1
6 2 2 1 1
Only designs 3 and 4 meet availability requirements – avoid the others
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Adding more VIOC LPARs
Using the same FCs on the VIOSRotate LPARs across SVC ports
Using other FCs on the VIOSRotate LPARs across port sets
Using a balanced resource approach is cost effective Where bandwidth of host ports = bandwidth of storage ports Bandwidth of ports varies depending on the model Latest HW: SVC port bandwidth of about 40,000 IOPs, Host port bandwidth around 50,000 IOPS
Option on right is more balanced
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1 SVC node2
vFC1
Power Server
SVC IO Group
vFC2
vFC3
vFC4
LPAR2
vFC1
vFC2
vFC3
vFC4
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1 SVC node2
vFC1
Power Server
SVC IO Group
vFC2
vFC3
vFC4
LPAR2
vFC1
vFC2
vFC3
vFC4
4 host ports 8 host ports
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Adding SVC IO Groups
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
vFC2
vFC3
vFC4
SVC node3
SVC node4
SVC IO Group
Allows additional SVC resources to be usedNode processors and cache
LUNs are served up from one IO group onlyStill 4 paths/LUN
The zoning changes:
Zone1: vFC1 WWPN1, N1P1, N3P1Zone2: vFC1 WWPN2, N1P1, N3P1Zone3: vFC2 WWPN1, N2P3, N4P3Zone4: vFC2 WWPN2, N2P3, N4P3Zone5: vFC3 WWPN1, N2P1, N4P1Zone6: vFC3 WWPN2, N2P1, N4P1Zone7: vFC4 WWPN1, N1P3, N3P3Zone8: vFC4 WWPN2, N1P3, N3P3 Italic zones are for inactive WWPNs
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To add bandwdith to a VIOC, one must add more physical adapter ports Add one port with 1 additional path or Add a set of ports
Adding IO bandwidth to a VIOC LPAR
LPAR1
VIOS1 VIOS2
SAN1 SAN2
SVC node1
SVC node2
vFC1
Power Server
SVC IO Group
vFC2
vFC3
vFC4
vFC5
vFC6
vFC7
vFC8
Zone the new ports like the old portsStorage administrator assigns LUNs to new host ports, orMove half or some of the LUNs to the new port set
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Error message from SVC
The GUI panel shows the 4 paths to the inactive host WWPNs used by LPM as Offline This is normal and expected behavior with LPM
The GUI panel also shows the 4 active host paths used for I/O as “Degraded” This is expected behavior but development is looking at a change in the future
The “# Nodes Logged In” column shows how many nodes in cluster see the host ports
The current SVC code (as of 12/2011) displays a “Degraded” path warning message when a host port is zoned to only one node in an I/O group, even if the second host port is zoned to the other node in the same I/O group providing path redundancy to a volume:
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Disk Path Design tech doc: http://www.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101914
SDDPCM manual: http://www-01.ibm.com/support/docview.wss?rs=540&context=ST52G7&uid=ssg1S7000303
Dynamically adding a FC adapter to a partition tech doc: http://w3-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/TD105218
vFC adapter properties using NPIV tech doc: http://w3-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/FQ128819
Systems Hardware information center: Virtual Fibre Channelhttp://publib.boulder.ibm.com/infocenter/powersys/v3r1m5/index.jsp?topic=/iphat/iphblconfigvfc.htm
References
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