《EVA Concepts - HP EVA概念与术语》由会员分享，可在线阅读，更多相关《EVA Concepts - HP EVA概念与术语（21页珍藏版）》请在金锄头文库上搜索。
1、 2006 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice EVA Concepts and terminologyYu-Sheng GuoAccount Support ConsultantHP TaiwanObjectives Define the virtual storage terms applicable to the EVA Name the primary features of a disk group
2、and default disk group Describe the ways in which disk groups are configured Name the primary features of virtual disks Differentiate between conventional RAID and distributed virtual RAID (VRAID) technologyDateHP RestrictedVirtual storage terminology Storage system (cell) An initialized pair of HSV
3、 controllers with a minimum of eight physical disk drives Disk group A group of physical disks, from which you can create virtual disks Virtual disk A logical disk with certain characteristics, residing in a disk group Virtual disk leveling Distribution of all user data within the virtual disks in a
4、 disk group across all physical disks within the disk group Distributed sparing Allocated space per disk group to recover from physical disk failure in that disk group Host A collection of host bus adapters that reside in the same (virtual) server Logical Unit Number (LUN) A virtual disk presented t
5、o one or multiple hostsDateHP RestrictedStorage system Also called a cell, an initialized pair of HSV controllers with a minimum of eight physical disk drives Requires a name up to 20 characters longSpecial characters are not allowed (for example, ?, “, /, )Two consecutive spaces are not allowedName
6、 is changeable System initializationMakes the storage system ready for useBinds the controllers together as an operational pairCreates the first disk groupEstablishes preliminary data structures on the disk array (metadata)DateHP RestrictedStorage system metadata System-level metadata is stored on q
7、uorum disks and containsController informationWWN and cell name Character map of disk groups and virtual disk membersDateHP RestrictedDisk group A group of physical disks Maximum of 16 disk groups per array (7 for an eva3000)Minimum number of physical disk drives in a disk group is 8Maximum number o
8、f physical disk drives is the number present in the system up to 240 (up to 56 for the eva3000)Unassigned or new disks can be added to an existing groupMixed drive sizes within a group are allowed Disk failure protection levelNone, single, or double disk failures (not concurrent failure)Default is n
9、one (sparing will occur from unassigned capacity) Space is allocated in 2MB segments (PSEGs) Chunk size is 256 blocks (128KB), fixedDateHP RestrictedDefault disk group First disk group created Used like any other disk group Can be deleted after another disk group is created to protect metadata Can b
10、e renamedDateHP RestrictedDisk group metadata When a cell is created, there are five quorum disks in the default disk group Maximum of 16 quorum disks (one per disk group) When a new disk group is createdOne quorum disk is created on itOne quorum disk is removed from the default disk group until jus
11、t one quorum disk remains Metadata overhead is 0.2% of total disk group capacityDateHP RestrictedDisk group capacityDisk group has two types of capacity Assigned capacity Virtual disks, snapshots and clonesSpare space reserved for the protection level Unassigned capacity New virtual disk creation, s
12、napshots and clonesFreeing a physical disk for removal or reassignmentData reconstruction after disk failureIncreases when virtual disks are deleted or new physical disks are added to the disk groupDisk group capacityAssignedUnassignedDateHP RestrictedDisk group member terms Unpaired The disk that d
13、oes not contain VRAID1 (mirrored) data on it because the disk group was created with an odd number of drives or because it lost its mirror partner because of a failure Paired The disk that was previously unpaired. A disk was added to the group, which now contains an even number of disks.Moderately r
14、edundant volume (VRAID5)No redundancy volume (VRAID0) Highly redundant volume (VRAID1) VRAID1 pairVRAID1 pairVRAID1 pairVRAID1 pairDateHP RestrictedDisk group creation Physical stores (Pstores)Raw FC-AL disks VolumesPstores + metadata Logical disk allocation domain (LDAD)Grouping of physical disksCo
15、mmonly called a disk groupPstoreCreate volumeVolumeInsertLDADDateHP RestrictedVirtual disk A logical disk with certain attributes, such as size and VRAID level, residing in a disk group and spanning all members of the disk group Minimum size of 1GB and maximum size of 2TB (less 1GB) Maximum of 512 v
16、irtual disks VRAID levels for the virtual disks VRAID0 or striping (none) Distributed across all disk in a group 100% of disk group capacityVRAID5 or striping with parity (moderate) Distributed across all disk in a group Always five (4+1) physical disks per stripe are used 80% of disk group capacityVRAID1 or mirroring (high) Two physical disks pe
