摘要:
A method and a storage system are provided for implementing a sustained large block random write performance mechanism for shingled magnetic recording (SMR) drives in a redundant array of inexpensive disks (RAID). A Solid State Drive (SSD) is provided with the SMR drives in the RAID. The SSD is used in a hot spare mode, which is activated when a large block random-write event is identified for a SMR drive in the RAID. In the hot spare mode, the SSD temporarily receives new incoming writes for the identified SMR drive. Then the identified SMR drive is updated from the SSD to restore the state of the identified SMR drive, and operations continue with normal writing only using the SMR drives in the RAID.
摘要:
A method and a storage system are provided for implementing a sustained large block random write performance mechanism for shingled magnetic recording (SMR) drives in a redundant array of inexpensive disks (RAID). A Solid State Drive (SSD) is provided with the SMR drives in the RAID. The SSD is used in a hot spare mode, which is activated when a large block random-write event is identified for a SMR drive in the RAID. In the hot spare mode, the SSD temporarily receives new incoming writes for the identified SMR drive. Then the identified SMR drive is updated from the SSD to restore the state of the identified SMR drive, and operations continue with normal writing only using the SMR drives in the RAID.
摘要:
A shingled magnetic recording hard disk drive that uses writeable cache tracks in the inter-band gaps between the annular data bands minimizes the effect of far track erasure (FTE) in the boundary regions of annular data bands caused by writing to the cache tracks. Based on the relative FTE effect for all the tracks in a range of tracks of the cache track being written, a count increment (CI) table or a cumulative count increment (CCI) table is maintained. For every writing to a cache track, a count for each track in an adjacent boundary region, or a cumulative count for each adjacent boundary region, is increased. When the count value for a track, or the cumulative count for a boundary region, reaches a predetermined threshold the data is read from that band and rewritten to the same band.
摘要:
A shingled magnetic recording (SMR) hard disk drive (HDD) essentially eliminates the effect of far track erasure (FTE) in the boundary regions of annular data bands caused by writing in the boundary regions of adjacent annular data bands. The extent of the FTE effect is determined for each track within a range of tracks of the track being written. Based on the relative FTE effect for all the tracks in the range, a count increment (CI) table or a cumulative count increment (CCI) table is maintained for all the tracks in the range. For every writing to a track in a boundary region, a count for each track in an adjacent boundary region, or a cumulative count for the adjacent boundary region, is increased. When the count reaches a predetermined threshold the data is read from that band and rewritten to the same band.
摘要:
A shingled magnetic recording hard disk drive that uses writeable cache tracks in the inter-band gaps between the annular data bands minimizes the effect of far track erasure (FTE) in the boundary regions of annular data bands caused by writing to the cache tracks. Based on the relative FTE effect for all the tracks in a range of tracks of the cache track being written, a count increment (CI) table or a cumulative count increment (CCI) table is maintained. For every writing to a cache track, a count for each track in an adjacent boundary region, or a cumulative count for each adjacent boundary region, is increased. When the count value for a track, or the cumulative count for a boundary region, reaches a predetermined threshold the data is read from that band and rewritten to the same band.
摘要:
A shingled magnetic recording (SMR) hard disk drive (HDD) essentially eliminates the effect of far track erasure (FTE) in the boundary regions of annular data bands caused by writing in the boundary regions of adjacent annular data bands. The extent of the FTE effect is determined for each track within a range of tracks of the track being written. Based on the relative FTE effect for all the tracks in the range, a count increment (CI) table or a cumulative count increment (CCI) table is maintained for all the tracks in the range. For every writing to a track in a boundary region, a count for each track in an adjacent boundary region, or a cumulative count for the adjacent boundary region, is increased. When the count reaches a predetermined threshold the data is read from that band and rewritten to the same band.
摘要:
ICC-NCQ priority and deadline information in conjunction with an estimation of command access time that is specific to SMR drives are used improve command queue optimization. Estimated completion times are determined based on the internal subcommands that the drive has to execute to complete the host read or write command taking into account whether all or part of the data will be or already is stored in write-twice cache, E-region and/or I-region. The command processor selects the next command for execution based on calculated access times with adjusted priority based on the specified deadline for the command. As the deadline approaches, the priority of the command increases. For high priority data writes as specified by a host, an optimized storage plan is selected as appropriate using the “write-twice cache” (WTC) region, E-region or I-region.
摘要:
Approaches are provided for a hard-disk drive (HDD) and techniques for using multiple LUNs per HDD where each LUN is mapped to a head/disk interface. In one example, a HDD generates multiple LUNs and assigns each to a single head, such that data written by a first head is only associated to a first LUN, and so forth.
摘要:
A method and apparatus are provided for implementing enhanced performance for multi-level cell (MLC) memory using threshold-voltage-drift or resistance-drift tolerant moving baseline memory data encoding. A voltage baseline of a prior write is identified, and a data write uses the threshold-voltage-drift or resistance-drift tolerant moving baseline memory data encoding for data being written to the MLC memory responsive to the identified voltage baseline.
摘要:
A method and apparatus are provided for implementing secure erase for solid state drives (SSDs). An encryption key is used to encrypt data being written to SSD. A controller identifies a key storage option, and responsive to the identified key storage option, stores a key for data encryption and decryption. The controller deletes the key within the SSD responsive to the identified key storage option, ensuring that once the key is deleted, the key is not recoverable and data is effectively erased.