IO Timeout in pvdisplay

[Hananeel]

what is the default IO Timeout for a disk in pvdisplay? how to change the default value?

what happens if we can change the IO value? Do we get any performance on Disk level?

[g3jza]

Hi,
this attribute can be tuned with #scsimgr in 11.31. It is called path_fail_secs.

#man scsimgr_esdisk.

[g3jza]

for example:

scsimgr get_attr -D /dev/rdisk/disk58 -a path_fail_secs

SCSI ATTRIBUTES FOR LUN : /dev/rdisk/disk58

name = path_fail_secs
current = 120
default = 120
saved =

so it should by 120sec by default

[Duncan Edmonstone]

Default IO timeout on HP-UX is 30 seconds - playing with it is unlilely to change performance - generally you should change it only if advised to do so by your storage vendor.

HTH

Duncan

[Hananeel]

Thanks .. now it is cleared... :-)

[Duncan Edmonstone]

g3jza,

path_fail_secs is not I think the same thing as the default IO timeout that you see from a pvdisplay command... this is specific to declaring a lunpath as offline... I think the one you were thinking of is probably esd_secs.

If not set seperately via the pvchange command, LVM will inherit the default for the undelying disk subsystem - which is usally 30 seconds on HP-UX

HTH

Duncan