Abstract: A method is used in managing data in a data storage system. A tiered storage pool is identified wherein the storage pool includes multiple tiers having multiple storage units. A wear indicator for each of the multiple storage units is monitored. A first storage unit having a wear indicator greater than a second storage unit is identified. High activity data on the first storage unit is also identified. The identified high activity data is migrated from the first storage unit to the second storage unit.

Abstract: A method is used in managing data deduplication in storage systems based on storage space characteristics. Characteristics of first and second storage tiers are evaluated. A first data object resides on the first storage tier and a second data object resides on the second storage tier. The first and second data objects are selected for applying a deduplicating technique. A data storage system includes the first and second storage tiers configured such that performance characteristics associated with the first storage tier is different from the second storage tier. Based on the evaluation, the deduplicating technique is applied to the first and second data objects.

Abstract: A method is used in managing storage space of storage tiers. Storage space utilization characteristics of a storage tier of a set of storage tiers in a storage system are evaluated. Based on the evaluation, reservation of headroom storage space in the storage tier is adjusted. The headroom storage space indicates an amount of the storage space reserved as unused storage space in the storage tier.

Abstract: A method is used in managing data deduplication in storage systems based on I/O activities. I/O activity of first and second data objects is evaluated. The first and second data objects are selected for applying a deduplicating technique. Based on the evaluation, the deduplicating technique is applied to the first and second data objects.

Abstract: A method is used in managing data deduplication in storage systems. Characteristics of first and second data objects are evaluated based on a set of deduplication policies. The first and second data objects are selected for deduplication. Based on the evaluation, deduplication performed on the first and second data objects is affected.

Abstract: A method is used in managing deduplication density. A deduplication density of a data object is determined. The deduplication density is indicated by a number of deduplicated data objects represented by the data object. Based on the deduplication density of the data object, the data object is skipped for applying a deduplicating technique to the data object. An association is created between the data object and another data object. The other data object is used for applying the deduplicating technique where contents of the other data object are identical to contents of the data object.

Abstract: A method is used in managing deduplication density. A deduplication density of a data object is determined. The deduplication density is indicated by a number of deduplicated data objects represented by the data object. Based on the deduplication density of the data object, a deduplicating technique is applied to the data object.

Abstract: A method is used in measuring data access activity. I/O data is analyzed that describes I/O activity for a slice of a logical volume. Based on the I/O data, a first value of data access activity is determined for the slice corresponding to a first time period, and a second value of data access activity is determined corresponding to a second time period. From the first and second values, an exponential moving average of data access activity is derived for the slice.

Abstract: A method is used in applying data access activity measurements. A slice relocation candidate list is generated which identifies slices to be relocated along with respective destination tier information. Slices in a pool are matched to respective matching tiers based on the slices' respective temperatures and tier preferences. Based on whether a current tier for a slice differs from the matching tier for the slice, the slice is listed in the relocation candidate list.

Abstract: A storage object such as a virtual disk drive or a raw logical volume is contained in a UNIX compatible file so that the file containing the storage object can be exported using the NFS or CIFS protocol and shared among UNIX and MS Windows clients or servers. The storage object can be replicated and backed up using conventional file replication and backup facilities without disruption of client access to the storage object. For client access to data of the storage object, a software driver accesses the file containing the storage object. For example, a software driver called a virtual SCSI termination is used to access a file containing a virtual SCSI disk drive. Standard storage services use the SCSI over IP protocol to access the virtual SCSI termination. An IP replication or snapshot copy facility may access the file containing the virtual SCSI disk drive using a higher-level protocol.

Abstract: The SCSI and iSCSI layers over the TCP/IP layers of the protocol stack in an IP network client and in an IP network-attached storage server are replaced with a thin network block services layer. The network block services layer 71 implements a network block services protocol having a very reduced set of commands transmitted between the client and the storage server. The network block services protocol is used in a configuration process in which logical volumes of the network-attached storage are exported to the client and become local pseudo-disk instances. The client's operating system and application programs access the local pseudo-disk instances with what appears to be a standard device driver for a local disk device. The device driver maintains a TCP connection to each open device, and responds to connection failure by re-connecting with an alternative server IP port.

Abstract: The SCSI and iSCSI layers over the TCP/IP layers of the protocol stack in an IP network client and in an IP network-attached storage server are replaced with a thin network block services layer. The network block services layer 71 implements a network block services protocol having a very reduced set of commands transmitted between the client and the storage server. The network block services protocol is used in a configuration process in which logical volumes of the network-attached storage are exported to the client and become local pseudo-disk instances. The client's operating system and application programs access the local pseudo-disk instances with what appears to be a standard device driver for a local disk device. The device driver maintains a TCP connection to each open device, and responds to connection failure by re-connecting with an alternative server IP port.