Limit on the number of concurrent SnapVault targets

Starting with Data ONTAP 7.3, the maximum possible number of concurrent SnapVault transfers of individual qtrees on a storage system is greater than the maximum number in Data ONTAP 7.2. However, maximum number of concurrent SnapVault targets did not change between release families.

Before Data ONTAP 7.3, the maximum number of concurrent SnapVault targets supported by a storage system was equal to the maximum number of concurrent SnapVault transfers possible for the system. A SnapVault target is a process that controls the creation of a scheduled SnapVault Snapshot copy on a SnapVault destination volume. For each SnapVault destination volume that has qtrees being updated, there will be a SnapVault target.

The maximum number of concurrent SnapVault targets for each platform is described in the following table. At any point in time, no more than the listed number of volumes can have their qtrees updated concurrently. If the number of SnapVault targets exceeds the limit mentioned in the table, the excess SnapVault targets are queued and executed after the active SnapVault targets complete their backups.

Table 1. Maximum number of concurrent SnapVault targets
Model	Maximum number of concurrent SnapVault targets
FAS250	4
FAS270	8
FAS920	8
FAS940	16
FAS960	16
FAS980	16
FAS2020	16
FAS2050	32
FAS3020	32
FAS3040	64
FAS3050	64
FAS3070	128
FAS3140	64
FAS3160	128
FAS3170	128
FAS6030	96
FAS6040	96
FAS6070	128
FAS6080	128

Note: These maximum numbers apply only to SnapVault targets, and therefore to SnapVault qtrees. There is no restriction on the number of volumes that can be updated concurrently for SnapMirror qtrees.

Although there is a maximum number of concurrent SnapVault targets, you can configure SnapVault relationships in as many volumes as required. However, at any point in time, only the qtrees in the limited number of volumes can be updated.

If the SnapVault backup throughput is limited by the bandwidth or latency of individual links between multiple primary storage systems and the secondary storage system, you can use the enhanced number of concurrent transfer limits available in Data ONTAP 7.3 to get higher overall throughput. You can use the higher limits by spreading the qtrees in the specified number of volumes.