An issue exists in Storwize V7000 and SAN Volume Controller V18.104.22.168 and V22.214.171.124 that can cause severe performance impacts to iSCSI-connected hosts that use SCSI-2 reservations.
Examples of iSCSI host types that are known to use SCSI-2 reservations include VMware and some host clustering technologies.
Host types that use SCSI-2 reservations will be unable to clear these reservations when connected via iSCSI to a Storwize V7000 or SAN Volume Controller system running V126.96.36.199 or V188.8.131.52.
This may lead to severe performance impacts on an affected host as it repeatedly attempts and fails to clear reservations.
V6.3.0.x and earlier are unaffected by this issue.
This issue was resolved by APAR IC84909 in the V184.108.40.206 PTF release.