Originally posted by: nelson1978

i have a 2 fcs0,fcs1 adapter in p520 server which connected to DS4800 in my environment .
lsdev -C | grep dar
dar0 Available 1815 DS4800 Disk Array Router
en0 Available 00-08 Standard Ethernet Network Interface
en1 Defined 09-08 Standard Ethernet Network Interface
en2 Defined 09-09 Standard Ethernet Network Interface
en3 Defined 0A-08 Standard Ethernet Network Interface
en4 Available Standard Ethernet Network Interface

fget_config -l dar0
dac2 ACTIVE dac3 ACTIVE
hdisk3 dac2
hdisk2 dac3
hdisk4 dac3
hdisk5 dac2
hdisk6 dac3
hdisk7 dac2
hdisk8 dac2
hdisk9 dac3
hdisk10 dac2
hdisk11 dac3

fget_config -v -A

---dar0---

User array name = 'Cadence_DS4800'
dac2 ACTIVE dac3 ACTIVE

Disk DAC LUN Logical Drive
utm 31
hdisk3 dac2 0 o_backup
hdisk2 dac3 1 o_nimvg
hdisk4 dac3 2 o_backup2
hdisk5 dac2 3 o_backup3
hdisk6 dac3 4 o_backup4
hdisk7 dac2 5 o_backup5
hdisk8 dac2 6 o_veritasvg
hdisk9 dac3 7 o_veritasvg2
hdisk10 dac2 8 o_veritasvg3
hdisk11 dac3 9 o_backup6
hdisk12 dac2 10 o_backupvg7

can anyone please tell me it has redundancy ?
or is there any command to find out that it has multipath to the SAN?
#AIX-Forum

Originally posted by: hdkutz

Hello,
<snip>
fget_config -v -A

---dar0---

User array name = 'Cadence_DS4800'
dac2 ACTIVE dac3 ACTIVE

Disk DAC LUN Logical Drive
utm 31
hdisk3 dac2 0 o_backup
hdisk2 dac3 1 o_nimvg
hdisk4 dac3 2 o_backup2
hdisk5 dac2 3 o_backup3
hdisk6 dac3 4 o_backup4
hdisk7 dac2 5 o_backup5
hdisk8 dac2 6 o_veritasvg
hdisk9 dac3 7 o_veritasvg2
hdisk10 dac2 8 o_veritasvg3
hdisk11 dac3 9 o_backup6
hdisk12 dac2 10 o_backupvg7
<snip>
indicates to me, that you are using 2 DAC's under dar0 Device (ac2 and dac3) which are both active.
Lucky guy.
Seems that you are redundant.

Cheers,
ku
#AIX-Forum

Originally posted by: bhimsingh

Even if it shows dac2 and dac3 are active does not mean that each disk is redundant , it will still show both the dacs active if any of the disk is mapped with both disk array controller or there are two disk array controller in one dar .

as per my knowledge , there is no command at OS side which can show if the disk is redundant if you are only using rdac .But if you multipathing software install ( MPIO ) then you can see with lspath command . Two paths should be there for each disk
bash-2.04# lsdev -Cc disk|grep hdisk185
hdisk185 Available 05-00-02 MPIO Other DS4K Array Disk

bash-2.04# lspath -l hdisk185
Enabled hdisk185 fscsi0
Enabled hdisk185 fscsi1

Hope it helps .
#AIX-Forum

Originally posted by: bhimsingh

Even if it shows dac2 and dac3 are active does not mean that each disk is redundant , it will still show both the dacs active if any of the disk is mapped with both disk array controller or there are two disk array controller in one dar .

as per my knowledge , there is no command at OS side which can show if the disk is redundant if you are only using rdac .But if you multipathing software install ( MPIO ) then you can see with lspath command . Two paths should be there for each disk
bash-2.04# lsdev -Cc disk|grep hdisk185
hdisk185 Available 05-00-02 MPIO Other DS4K Array Disk

bash-2.04# lspath -l hdisk185
Enabled hdisk185 fscsi0
Enabled hdisk185 fscsi1

Also , you can check with "manage_disk_drivers" which drivers are installed to support your DS4K storage and run appropriate command

bash-2.04# manage_disk_drivers
1: DS4100: currently MPIO; supported: RDAC/fcparray, MPIO
2: DS4300: currently MPIO; supported: RDAC/fcparray, MPIO
3: DS4500: currently MPIO; supported: RDAC/fcparray, MPIO
4: DS4700/DS4200: currently MPIO; supported: RDAC/fcparray, MPIO
5: DS4800: currently MPIO; supported: RDAC/fcparray, MPIO
bash-2.04#

MPIO is supported on this machine hence you can use lspath as well as mpio_get_config -Av to get the similiar output as produced by fget_config -Av

root@CNDABBCUDBDP11:/$ manage_disk_drivers
1: DS4100: currently RDAC; supported: RDAC/fcparray, MPIO
2: DS4300: currently RDAC; supported: RDAC/fcparray, MPIO
3: DS4500: currently RDAC; supported: RDAC/fcparray, MPIO
4: DS4700/DS4200: currently RDAC; supported: RDAC/fcparray, MPIO
5: DS4800: currently RDAC; supported: RDAC/fcparray, MPIO
root@CNDABBCUDBDP11:/$

RDAC is the supported software , so you can use only fget_config -Av and no other option to see the disk redundancy .
#AIX-Forum

Originally posted by: jvk

He is fine.
A DS4k box is an "active-passive" box so only one path at time per hdisk is used. One can spread disks between two controllers but still only one path at time per hdisk is used. If something happens to one path, then all hdisks who have a preferred path there should fail-over to the second controller/path.
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