Technical White Paper Dell EMC PowerStore: File Capabilities Abstract This document discusses the features, functionality, and protocols supported by the Dell EMC™ PowerStore™ file architecture. April 2021 H18155.3 Revisions Revisions Date Description April 2020 Initial release: PowerStoreOS 1.0 July 2020 Minor updates September 2020 PowerStoreOS 1.0.2 updates April 2021 PowerStoreOS 2.0 updates Acknowledgments Author: Wei Chen The information in this publication is provided “as is.” Dell Inc. makes no representations or warranties of any kind with respect to the information in this publication, and specifically disclaims implied warranties of merchantability or fitness for a particular purpose. Use, copying, and distribution of any software described in this publication requires an applicable software license. This document may contain certain words that are not consistent with Dell's current language guidelines. 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[4/13/2021] [Technical White Paper] [H18155.3] 2 Dell EMC PowerStore: File Capabilities | H18155.3 Table of contents Table of contents Revisions............................................................................................................................................................................. 2 Acknowledgments ............................................................................................................................................................... 2 Table of contents ................................................................................................................................................................ 3 Executive summary ............................................................................................................................................................. 6 Audience ............................................................................................................................................................................. 6 1 Introduction ................................................................................................................................................................... 7 1.1 PowerStore file capabilities ................................................................................................................................ 7 1.2 Terminology ........................................................................................................................................................ 7 2 Unified appliances ........................................................................................................................................................ 8 3 NAS servers ............................................................................................................................................................... 10 3.1 Multitenancy ...................................................................................................................................................... 10 3.2 High availability ................................................................................................................................................. 10 3.3 Interfaces .......................................................................................................................................................... 10 3.4 NAS server parameters .................................................................................................................................... 11 4 Protocols ..................................................................................................................................................................... 13 4.1 SMB .................................................................................................................................................................. 13 4.1.1 Sync writes ....................................................................................................................................................... 14 4.1.2 Oplocks ............................................................................................................................................................. 14 4.1.3 Notify on write or access enabled ..................................................................................................................... 15 4.1.4 Continuous availability ...................................................................................................................................... 15 4.1.5 Protocol encryption ........................................................................................................................................... 15 4.1.6 Access-based enumeration .............................................................................................................................. 16 4.1.7 BranchCache .................................................................................................................................................... 16 4.1.8 Offline availability .............................................................................................................................................. 16 4.1.9 DFS ................................................................................................................................................................... 17 4.1.10 File extension filtering................................................................................................................................... 17 4.2 NFS ................................................................................................................................................................... 18 4.2.1 NFSv4 ............................................................................................................................................................... 18 4.2.2 Secure NFS ...................................................................................................................................................... 19 4.2.3 Minimum security .............................................................................................................................................. 19 4.2.4 Default host access .......................................................................................................................................... 19 4.3 FTP and SFTP .................................................................................................................................................. 21 5 Multiprotocol ............................................................................................................................................................... 23 5.1 User mapping ................................................................................................................................................... 23 3 Dell EMC PowerStore: File Capabilities | H18155.3 Table of contents 5.1.1 SMB mapping ................................................................................................................................................... 25 5.1.2 NFS mapping .................................................................................................................................................... 25 5.1.3 Secure mapping cache ..................................................................................................................................... 25 5.1.4 Ntxmap ............................................................................................................................................................. 26 5.1.5 Automatic mapping for unmapped Windows accounts .................................................................................... 26 5.1.6 Default accounts for unmapped users .............................................................................................................. 26 5.1.7 Mapping process .............................................................................................................................................. 27 5.2 Permissions ...................................................................................................................................................... 30 5.2.1 Access policy .................................................................................................................................................... 30 5.2.2 UMASK ............................................................................................................................................................. 31 5.3 Multiprotocol policies ........................................................................................................................................ 32 5.3.1 Locking policy ..................................................................................................................................................