Alternate path support for fibre attached drives

[cdacunha]

Env : TSM 5.1 /AIX 5.1 ML03 with latest Atape driver.



We have 6 x 3590E drives in our library, each drive has two ports and each port is connected to a different switch. The TSM server also has two hba's and each is connected to a different switch .



So at AIX level I see 12 drives ! If you enable alternate path support AIX recognizes that these are identical drives and sets the status accordingly ( either primary or alternate )



Here's the output of lsdev -Cctape



rmt1 Available 3M-08-01-PRI IBM 3590 Tape Drive and Medium Changer (FCP)

rmt2 Available 3M-08-01-PRI IBM 3590 Tape Drive and Medium Changer (FCP)

rmt3 Available 3M-08-01-PRI IBM 3590 Tape Drive and Medium Changer (FCP)

rmt4 Available 3M-08-01-PRI IBM 3590 Tape Drive and Medium Changer (FCP)

rmt5 Available 3M-08-01-PRI IBM 3590 Tape Drive and Medium Changer (FCP)

rmt6 Available 3M-08-01-PRI IBM 3590 Tape Drive and Medium Changer (FCP)

rmt7 Available 4s-08-01-ALT IBM 3590 Tape Drive and Medium Changer (FCP)

rmt8 Available 4s-08-01-ALT IBM 3590 Tape Drive and Medium Changer (FCP)

rmt9 Available 4s-08-01-ALT IBM 3590 Tape Drive and Medium Changer (FCP)

rmt10 Available 4s-08-01-ALT IBM 3590 Tape Drive and Medium Changer (FCP)

rmt11 Available 4s-08-01-ALT IBM 3590 Tape Drive and Medium Changer (FCP)

rmt12 Available 4s-08-01-ALT IBM 3590 Tape Drive and Medium Changer (FCP)



We configured the 12 drives and paths in TSM . Since there are only 6 physical drives we only put 6 of them online ( 3 on each switch ) and in case of problems we manually adapt our configuration .



But I'm not sure that this is the best way to implement this. Has anyone a similar setup and using another strategy ?

 

[heada]

I have a similar setup, but I have 9 drives (18 rmt devices) in a 3494. I only defined the 9 primary connections.(5 on one switch, 4 on the other) From what I read on the alt pathing in the latest atape, AIX will automaticly switch to using the alt connection behind the secenes (TSM is unaware of this) and continue on it's merry way. I have not tested this since I have not had any free time on my library since putting this in place (all 9 drives are busy all the time)



-Aaron