VA7410

[Faizer]

Hi Gurus;
I have a va7410 with 1TB capacity. This array is configured as follows.

Redundancy G1: Logical drives: 205gb Unallocated: 151gb redundancy:110gb active spare: 66.75 total: 534gb
Redundancy G2: Logical drives: 335gb Unallocated: 7gb redundancy:91gb active spare: 33 total: 467gb


Based on the above is the undermentioned assumptions correct.
1. The array has 2 groups of disk namely RG1 and RG2.
2. The active spare and the redundancy works on an algorithm that is factory set for the Array.
3. In the event of a disk failures then sequence of events is as follows
First the active spare disk in the respective Redundancy group is used till it becomes zero.
Then the Redundancy disk space is used up till it becomes zero before the respective redundancy group crashes/ is unavailable

Also let me know the high availability of this array.
Thanking you in advance
Faizer

[Eugeny Brychkov · Accepted solution]

Faizer,
1. yes. disks in odd slots (1,3,5..) are within RG1 and disks in even slots (2,4,6...) are in RG2;
2&3. Active hot spare is not a dedicated disk. It's space spread across all the disks. Space reservation size depends on which disks of which size you have installed into VA. Please also note that AHS is global VA setting, although each RG has its AHS. This means that if disk in RG1 will fail then rebuild will be done into RG1's AHS area. If, after rebuild, there will be enough free space left then VA will re-reserve AHS area. If there will be lack of the space then next disk failure will cause VA to be reconstructing data "on the fly" (by host's demand), and data will be still available. VA will be in 'redundancy loss' state. If then next disk will fail, then VA may deactivate LUNs within RG because of 'data unavailable' or data may be still available (depends on which disk will fail). The best practice is to replace failed disk ASAP, but only after rebuild will complete successfully.
About availability: very available system. RAID 0+1: "array will continue operation without data loss in the event of any non-adjacent disk" thus is proof to multiple non-adjacent disks failures;
RAID5DP: "RAID 5DP uses two algorithms to create two independent sets of redundancy data. This allows the array to reconstruct RAID 5DP data in the event to two simultaneous disk failures".
VA's firmware allocates data by itself using best-performance and best-reliability algorithms.
Please find more information in VA's guides at http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual&docIndexId=3124&locale=en_US&prodSeriesId=89018&prodTypeId=12169
Eugeny