Term
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Definition
| Creates point-in-time views (SnapShot) and copies (Clones) of logical volumes. Allows multiple copies of data (parallel access). Runs on CLARiiON. Instantly available and R/W capable. |
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Term
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Definition
| Pointer based. Only require fraction of source disk space. Copy on First Write. 8 snaps possible with single source volume/ Snapshot. Snapshots of clones are suported. "Roll back" provides instant restore to source volume. |
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Term
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Definition
| Full volume copy. Requires equal disk space. |
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Term
| 3 Components of Virtual LUN |
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Definition
1) Source LUN
2) Pointer Memory Map
3) Save Area |
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Term
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Definition
| May have only 1 view of a LUN active at any time. May be source LUN or one of 8 snapshots. No host may have Source LUN and Snapshot accessible to it at the same time. |
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Term
| SnapView Backup (secondary) host |
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Definition
| Host where backup processing occurs. Accesses snapshots. Must be same OS type as production host for filesystem access (unless raw data). |
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Term
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Definition
| LUN from which Snapshots will be made |
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Term
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Definition
| "Frozen in time" copy of Source LUN. Up to 8 R/W snapshots per source LUN. Accessible to secondary host, but not to primary host once SnapView session = started. Used when only write to 20 - 30% of data. Appears "off-line" until session is activated. Copy on First Write. |
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Term
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Definition
| Private area used to hold original data from Source LUN when host writes to a chunk for first time (contain copy on first write). 1 LUN Pool per SP. All Snapshot Sessions owned by a SP use 1 LUN Pool. Each Source LUN with active session is allocated 1+ Reserved LUNs. Fraction of Source LUN size. |
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Term
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Definition
| should be same size as original. |
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Term
| Downsides to SnapView SnapShot |
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Definition
1) Not as fault tolerant as Clone
2) Contention bwtn source and LUN
3) More overhead in memory and CPU process to keep track of memory map |
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Term
| Benefits of SnapView SnapShot |
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Definition
1) Instantly have virtual LUN
2) Uses fraction of space |
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Term
| Benefits of SnapView Clone |
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Definition
1) Safe: used for mission Critical information
2) higher level of service than Snapshot |
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Term
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Definition
| Can be started / stopped from SnapView Manager/CLI or from production host via "admsnap". Requires session name. |
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Term
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Definition
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Term
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Definition
| SnapView snapshot original saved data. Fixed size of 64 KB. Saved when modified for the first time. Saved once per snapshot. |
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Term
| Deactivation of SnapView Session |
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Definition
| Makes snapshot inaccessible to the Backup host. Keeps COFW process active. Does not flush host buffers. |
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