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Questions tagged [raid]

RAID, an acronym originally for Redundant Array of Inexpensive Disks (today usually interpreted as referred to as Redundant Array of Independent Disks), is a technology that provides increased storage performance and reliability through redundancy by spreading data across multiple disks using various algorithms (RAID-levels). RAID can be implemented in hardware storage controllers, or in software, usually as operating system/kernel features.

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Why do I need a raid battery pack?

I'm trying to understand why one would add a batterypack to a raid card. It seems to me like if power goes down, running just the raid card is going to do little good: without power for HDs and motherboard, writing in-memory data isn't going to work…
user60704
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Recommended disk/partition setup for a SQL Server

I'm looking for some advice regarding the best way to set up my disks/partitions for SQL Server. Here are some of my major concerns: How should the SQL files be seperated (data files, logs, temp)? Is it better to RAID a lot of HDDs and partition the…
Shane
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How do you backup a storage server?

I'm looking at implementing a very large storage server to be used as live NAS for several other servers (all Linux-based). By very large, I mean between 4TB and 20TB usable space (although it's unlikely we'll actually make it 20TB). The storage…
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When is RAID worth the trouble?

In our shop we're faithfully using RAID in all our workstations, probably just because that seems to be the way it ought to be done. I'm talking about workstations for scientific simulations, using the onboard RAID chips. But I've heard a lot of…
amarillion
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What is the fastest and safest RAID combination for SATA drives?

I wonder what is the fastest and safest RAID combination for SATA drives and general use (some write, mostly read)? RAID 0 is fast but utterly unsafe, RAID 1 is safe but slow, RAID 5 is safe but not so fast, especially on the cheap controllers (XOR…
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What is a (raid-controller-) BBU for?

I am wondering what's the purpose of a BBU. My first understanding was, that it enables the cache to write the data to the disc during a power failure. But some specifications say that a BBU can hold its data for up to 72h. I'd expect the data to be…
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Linux - RAM Disk as part of a Mirrored Logical Volume

We have a server with 64GB of total RAM, applications are using typically a maximum of 30GB of that available RAM. One of those applications deals with a lot of flat files, and we're having throughput issues, namely waiting on disk I/O. While…
Shayne Fitzgerald
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Should I run my database off of a RAID 5 configuration?

I've heard that the write performance of RAID 5 can be appalling at times. While I want the redundancy that it provides I don't want to sacrifice my database insert/update times. Is this something I should be worried about and if so, what would be…
Scott Saad
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Battery Backed Write Cache

I recently got some U server price quotes and some of them include BBWC: What exactly does it do? Is it just for RAID configurations? If there is a power malfunction, isn't the data loss inevitable? Are there any performance improvements from it…
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What is a RAID Controller's Sideband Cable used for?

I have some Adaptec SAS raid controllers and the fanout cable comes with an extra cable called a SideBand but I am curious what it does? I know it plugs into the backplane, but other than that I can't seem to find anything on google The adaptec site…
Chad Grant
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Managing battery relearn cycles on LSI and similar RAID controllers

How do engineers deal with RAID controller battery "relearn" cycles? As noted in: What's a "battery relearn" on a LSI MegaRaid?, relearn cycle discharges the RAID controller battery (BBWC or BBU), thus removing the write cache acceleration. The…
ewwhite
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Can't enter HP SmartArray P410 RAID ORCA set-up on HP ProLiant DL320G6

I've just installed an HP SmartArray P410 controller into my HP ProLiant DL320G6 server. The controller seems detected by the server BIOS (it shows up in controllers list in the BIOS set-up), hard drives LEDs flash, but the controller is never…
Ivan
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RAID configuration for large NAS

I'm thinking of building a 24 1TB disk NAS box, but I'm not sure what the best drive configuration is. I'm looking at using the areca ARC-1280ML-2G controller, and hanging all 24 drives off of it. I'd like it all to be mounted as one volume, due to…
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How to do the equivalent of Synology Hybrid Raid on Linux myself?

http://forum.synology.com/wiki/index.php/What_is_Synology_Hybrid_RAID%3F Synology is just Linux and uses LVM. How do their tools automate LVM to achieve what they call their Hybrid Raid?
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How do I rename an mdadm raid array?

I have assembled a new raid array to replace an old one. However, this new array got assigned an automatic name of /dev/md127 and I want to rename it to /dev/md3, so that I don't have to change various other settings. How do I rename an mdadm raid…
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