Benefits of Hardware RAID

posted Nov 20, 2008, 1:28 AM by janet@wavelet.biz   [ updated Nov 20, 2008, 1:29 AM ]
To better safe guard your data and ensure smooth operations, and of cause a peace of mind, Wavelet Support Team would like to recommend that your database server be installed with Hardware RAID1 (Mirroring RAID).

What does Hardware RAID1 do?
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To configure Hardware RAID1, you will need 2 identical harddisks. However, the Operating System will only Read from 1 harddisk but all Write operations are done on both the harddisks at real-time.


Benefits of RAID1
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Wavelet has implemented automated backup scripts on all database servers. As this backup script only runs once a day (middle of the night) when no one is using the system, it also means that the backup data is only up till yesterday. Should any mishap happened to the database server's harddisk during the middle of the day, not only you will not be able to recover the entire day's transactions, your operation on that day will also be disrupted until a new harddisk is installed.

However, with Hardware RAID1 installed on your database server, all your data will be written to 2 harddidsks at real-time, even if 1 harddisk is down, you will be able to operate as normal, without any interruptions. Most importantly, no data will be lost


How to know when 1 harddisk has failed and what are the steps to take when it happens?
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Depending on the RAID Controller, the server usually sends out signal, example produce Beeping sound, blinking LED, etc.

When this happened, you may proceed with your operations as normal for the day. After operating hour :
1. Shut down the server
2. Unplug the failed harddisk
3. Plug in a new harddisk that is identical to the failed harddisk
4. Go to the RAID Controller interface and click Recorver to copy the entire data on the workable harddisk to the new harddisk


What is needed to support Hardware RAID1?
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1. Linux compatible with Hardware RAID1 support
2. 2 or 3 identical Harddisks, each with at least 80GB in size (recomended 15K RPM)
3. Minimum 3GB RAM


Under what kind of circumstances Hardware RAID can't help
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1. Both harddisks are physically damaged
2. Non-harddisks failure


What are the costs involved?
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1. Hardware Cost
   a) The hardware RAID Controller
   b) The hardisks
2. Installation Services: RM1000, includes the following
   a) Re-installation of Wavelet software in the new hardisk
   b) Data Migration from the old system to the new system
   c) Consultation on choosing the right RAID controller / hardisk configurations that is compatible with your server main board.

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