Some RAID and Backup questions

[forsakenseraph]

Hey guys, I am pretty new to RAIDs. Although I have heard of them, I have never used them. However, I'm filling up my 1 TB drive to where I am afraid that a hard drive failure will cause me to lose all my data (nothing mission critical, just lots and lots of personal stuff collected over the years). I have reached the following conclusion: I need some kind of redundancy. I plan to have 3 x 1 TB hard drives. I originally planned to have them in a RAID5 on an ASUS p5q pro motherboard.

1. Does anyone have any experience with RAID5 (or any RAID) on a p5q pro or similar motherboard? Specifically, Will a motherboard BIOS reset cause my RAID to die? How easy and time-consuming is it to rebuild a RAID5?

I have also considered putting 2 x 1TB in RAID1 with the more important data on it, and less important data on the unredundant drive. I like the economic efficiency of RAID5 and that is why I'm leaning heavily towards RAID5. However, I heard that RAID5 can be a pain sometimes, and most consumer versions are software based, and therefore decrease performance. (I'm not sure if this is true, just what I heard. Can anyone confirm or deny?)

2. Is there any preference over which setup is more preferable? I would like a setup that is easy to setup and pretty easy to rebuild.

Thanks in advance for any responses given. If additional information is desired to help provide advice, just let me know.

 

[Emulex]

Do not use raid-5 without a controller that has battery backed write cache.

that's all.

(intel matrix raid is software raid mostly)

 

[Nothinman]

Specifically, Will a motherboard BIOS reset cause my RAID to die? How easy and time-consuming is it to rebuild a RAID5?

I can't say for sure, but I wouldn't trust it.

However, I heard that RAID5 can be a pain sometimes, and most consumer versions are software based, and therefore decrease performance. (I'm not sure if this is true, just what I heard. Can anyone confirm or deny?)

Yes, virtually every consumer level RAID controller will be done in the driver and thus software. These days it doesn't matter too much though since CPUs can easily do the calculations required for RAID5 parity. On module load the Linux software RAID driver does some quick benchmarks to see which method of calculating parity is the quickest and this is what I got for my last bootup "xor: using function: generic_sse (7998.000 MB/sec)".

So, yes, write speed will be slower than no RAID5 however it shouldn't really be noticable and the redundancy tradeoff should be more than worth it.

2. Is there any preference over which setup is more preferable? I would like a setup that is easy to setup and pretty easy to rebuild.

I'm a fan of software RAID however I'm also running Linux and with Windows Vista and earlier you need a server build to get redundant levels of RAID. I believe the upper levels of Win7 give them but I can't really say for sure.

 

[jkresh]

in terms of speed as Nothinman said with software raid 5 write speed will be slower (possibly significantly) reads will be faster then 1 drive

you said raid and "Backup"

important thing to remember is raid is not a backup (raid 5, 1, 6...) if a drive fails raid will save you, but if you delete something or a virus corupts your data then raid does nothing. So even if you go with raid you should have any important stuff backed up somewhere else (I tend to prefer ghosting to an external which is off and unpluged when not running a backup).

 

[Emulex]

you have to essentially do a double read and write without cache this will probably drop a 4 drive raid-5 down to 30mb/s write speed (yes 30). it will read fast as heck but will be butt slow on write.

don't do it.

 

[Nothinman]

you have to essentially do a double read and write without cache this will probably drop a 4 drive raid-5 down to 30mb/s write speed (yes 30). it will read fast as heck but will be butt slow on write.

But he's just talking about data storage which in most cases is read-mostly, write rarely. As long as you're not using it for something needs good write speeds (i.e. VMs, databases, image editor scratch space, etc) it'll probably be fine.

 

[betaflame]

http://forums.anandtech.com/me...id=83&threadid=2324326

ICH-R's are pseudo-hardware, but the raid config is stored on the drives themselves, and even if he gets a power outage, whatever file he was copying to the raid at the time is hosed, and he simply recopies it from the source.

also RAID will only protect you from a drive failure, nothing else, it is not a backup.

 

[Emulex]

hit the reset button or cut power on your system while its writing. then let me know how the raid-5 write performance on rebuild affects your raid-5 rebuild.

 

[Nothinman]

hit the reset button or cut power on your system while its writing. then let me know how the raid-5 write performance on rebuild affects your raid-5 rebuild.

Or just own a UPS and don't be dumb?

 

[ch33zw1z]

Originally posted by: Nothinman

hit the reset button or cut power on your system while its writing. then let me know how the raid-5 write performance on rebuild affects your raid-5 rebuild.

Or just own a UPS and don't be dumb?

lol