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SCSI-3 reservations
Can anyone advise if there is a risk for setting the reserve policy to "no reserve" for disks in a cluster (POWER HA) environment.
And if there is a risk what type of remediation should be adopted.
EdwinVanMierlo
39 Posts
0
November 25th, 2014 01:00
Hi Steve,
It is a matter of knowing what the disk is being used for.
It depends on the Operating System and Application using the disk, if this [the OS & app] perform SCSI-3 Persistent Reservations then you need to set the bit (which is on by default in the latest code)
However, if the OS & app do not need SCSI-3 Persistent Reservations then it is no harm leaving it on.
So, IF:
- OS & app need it: ON (else you might impair functionality of OS & app)
- OS & app not need it: OFF or ON (it doesn't matter for functionality)
Hence we have chosen to have it on by default, as it does no harm.
It will only do harm when you turn it off and you need it....
HTH,
Edwin.
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Steve0_2012
73 Posts
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November 10th, 2014 05:00
It was'nt a recommendation from the vendor but the delivery team want to understand the risks for disabling or enabling the PER and how to remediate against same risks.
sauravrohilla
859 Posts
1
November 10th, 2014 05:00
is it a recommendation from the vendor? if vendor says they dont need PER bit on devices then just unset it...
Steve0_2012
73 Posts
1
November 25th, 2014 03:00
Thanks for the great feedback as always.