Author Topic: One question about storage!  (Read 1372 times)

bemficag

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One question about storage!
« on: July 28, 2009, 03:45:05 am »
Hi everyone,
I need some help, in my core I've been using raid 4 (4 hdd of 320gb each) for store  my data. And those are almost full. So, to increase space can I substitute new hdds with more gigas in this raid?? Or somebody has another option of storage that has redundancy?

thanks all

qball4

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Re: One question about storage!
« Reply #1 on: July 28, 2009, 04:11:34 am »
You might want to consider a solution like unRAID (www.lime-technology.com). It's not free, but you can expand up to 21 drives and they don't have to be the same size. You would need to dedicate a separate system for storage, though...

:Matt

bemficag

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Re: One question about storage!
« Reply #2 on: July 28, 2009, 05:45:00 am »
thanks matt,

I'll check it out.

all best

Thingie

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Re: One question about storage!
« Reply #3 on: July 28, 2009, 11:12:17 pm »
I don't think it's possible to extend an existing rais setup without losing the data on the disks. Not sure about this but if you can(t backup all this data and something goes wrong when fiddeling with the raid I'm pretty sure you'll loos all your data. So watch out before you try this.

bemficag

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Re: One question about storage!
« Reply #4 on: July 29, 2009, 05:43:45 am »
somebody else has another option???

merkur2k

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Re: One question about storage!
« Reply #5 on: July 29, 2009, 08:03:28 am »
are you sure its raid 4? very few people use raid 4 as raid 5 performs better for the same level of fault tolerance.
i do not know of any raid setups that can be dynamically resized. you have to copy the contents somewhere else, change disks, regbuild the array, and copy the contents back.
LVM can be extended dynamically, but its not redundant.

colinjones

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Re: One question about storage!
« Reply #6 on: July 29, 2009, 10:15:45 am »
The other thing is RAID 4 really hammers its parity drive. If you had just a 3 disk RAID 4, the parity drive gets hammered at least twice as much as the data drives during writing (particularly important if you are recording lots of TV), for a 4 disk arry, at least 3 times as much... it almost becomes self defeating in terms of redundancy. RAID 5 aleviates this issue, but both 4 and 5 have horrible write performance, especially for small and random writes. Dunno about mdadm but certainly most hardware RAID solutions can expand arrays semi-online... meaning you don't have to copy the data off, but you can't have the drive mounted at the time, and some can do it truly online.

In terms of separating tasks/responsibilities, I would suggest getting a NAS with RAID functionality, and divorce your data completely from your core/MDs, another option is FreeNAS software - Norcotek have some nice looking 5 bay NAS's that are compatible with FreeNAS, or simply build yourself a small/cheap PC with lots of drive bays and SATA connectors, and install FreeNAS on that.. can be a lot cheaper!

bemficag

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Re: One question about storage!
« Reply #7 on: July 30, 2009, 02:09:01 am »
How safe freenas is? This is has redundancy?? can use different  size of hdd??

merkur2k

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Re: One question about storage!
« Reply #8 on: July 30, 2009, 04:59:24 am »
it is the same as any other nas device that can do raid, and raid is raid no matter what the controller. the same stuff above applies.

bemficag

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Re: One question about storage!
« Reply #9 on: August 02, 2009, 12:04:24 am »
OK, after a hard research I found a cheaper solution (I think), and I'd like your opinion about it!
I have a core with 1 ide ata (system) and 4 sata (raid 5) slots that are already  full. So, what I thought was:
1) move my all data to usb device (1 tb usb hard drive);
2) substitute my 4 320gb hdd for 5 1tb hdd;
3) installation of PCI SATA Controller Card (http://www.newegg.com/Product/Product.aspx?Item=N82E16816150014), because I have only 4 on-board sata slot;
4) put back my data.

Any advice??

Thanks!

Thingie

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Re: One question about storage!
« Reply #10 on: August 02, 2009, 11:56:01 am »
OK, after a hard research I found a cheaper solution (I think), and I'd like your opinion about it!
I have a core with 1 ide ata (system) and 4 sata (raid 5) slots that are already  full. So, what I thought was:
1) move my all data to usb device (1 tb usb hard drive);
2) substitute my 4 320gb hdd for 5 1tb hdd;
3) installation of PCI SATA Controller Card (http://www.newegg.com/Product/Product.aspx?Item=N82E16816150014), because I have only 4 on-board sata slot;
4) put back my data.

Any advice??

Thanks!

Looks like a safe solution to me. Personally I use a seperate server (FreeNas) for my data. I found it much easier to work with it then when the disks where on my core.