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External RAID backup

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  • Hard Drives
  • NAS / RAID
  • Enclosure
  • External Raid
  • Storage
  • Product
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Anonymous
a b G Storage
August 27, 2010 9:29:08 AM

I have one of these:

http://www.startech.com/item/SAT3540U2E-35in-4-Drive-eS...

An external four-bay hard disk enclosure, with four 2TB drives inside. My intention is to use it as a backup for an 8TB RAID volume (also consisting of four 2TB drives); copying the entire disk over every weekend.

Its plugged in via USB, and came with no driver disk. The problem: when I try to convert the disks from basic to dynamic, I get an error 'This operation is not supported by the object'. Also, it will not let me convert the four drives into an 8TB spanned volume; I just get the same error.

When I mailed the manufacturer, they replied:

'This device is JBOB only. You cannot not use this with a RAID setup'

But surely if I'm just backing up it needs no RAID functions? I just need a straight copy.

My first guess would be to try connecting with ESATA instead (the enclosure can use both), but the machine has no port for it. Alternatively, maybe there is software which will just do a straight copy of each 2TB disk to each disk in the enclosure?

Any other ideas?

Many thanks.



More about : external raid backup

a c 182 G Storage
August 27, 2010 4:53:28 PM

1) If you are trying to copy several terabytes of data at once, it will take a very long time using usb2.0. That is one reason for developing usb 3.0.

2) If you do not have a esata port on your motherboard, I think you can get one by using a sata to esata adapter:
http://www.newegg.com/Product/Product.aspx?Item=N82E168... Esata should be a much faster process.

3) I think you may want to go to an incremental backup system. Initially, a complete backup is taken. Thereafter, only changes are backed up. In the event of needing recovery, the initial image is restored and the incremental changes applied.
You could then do an incremental backup more frequently, like daily. Perhaps monthly, a new complete image could be taken.
Check out Acronis for what their program will do. Also, such a backup will be compressed. The backup will take much less space than the original data. Compressing backups will also speed up the process because less data needs to be written out. I do not know if or how Acronis handles multiple large drives.

4) I suspect that a 2tb drive will hold the contents of your 8tb raid volume if the data is compressed. If that is true, then consider using a mobile rack. Such a rack goes in a spare 5 1/2" external bay and attaches to a sata port on your motherboard. The hard drive in it is removeable. You can then copy the contents of the logical raid volume to it at sata speeds. When done, you can remove the hard drive caddy and store it somewhere safe. Perhaps off site. Something like this:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
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a c 363 G Storage
August 27, 2010 6:18:30 PM

I agree that using the external box via eSATA would be much better than via USB2. VERY roughly, the data transfer speed would be twice as fast (MAYBE better) which is important considering the large volume of data you are handling.

HOWEVER, I do NOT suggest doing it the cheap simple way with an adapter. Doing that relies on having all the vital eSATA properties provided by your motherboard's regular SATA controller, and that is possible but not certain. But more importantly, the enclosure specs specifically state that to use eSATA you MUST have it connected to an eSATA port that supports Port Multiplier functions - otherwise you can only access ONE of its drives in eSATA connection mode. Presumably the actual Port Multiplier circuitry is in the enclosure, but for it to work you need support in the computer's eSATA controller, too.

SO, I recommend you search for a true eSATA controller board you can plug into a PCIe slot that DOES include Port Multiplier support.

What the manufacturer's reply of "You cannot not use this with a RAID setup" PROBABLY meant was that the unit does not have any RAID functionality built in so you cannot use it to create a RAID array inside it. But of course that is not what you are trying to do. You just want to use spanning (aka JBOD). But sometimes controllers that include RAID functions also throw in JBOD 'cause it is simple and cheap, and hence people start to confuse JBOD and the like with some version of RAID, which it is NOT.

I am not at all sure why your system objected to spanning, and I cannot comment on configuring as dynamic disks. I assume it works to the extent that each individual HDD inside it IS "visible" as a full stand-alone drive of 2 TB.
m
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l
January 21, 2011 8:10:25 PM

Hi,
I am having a simillar problem but, with a Mediasonic 2 bay.

Have you found out the issue?

Please let me know.

Thanks


Quote:
I have one of these:

http://www.startech.com/item/SAT3540U2E-35in-4-Drive-eS...

An external four-bay hard disk enclosure, with four 2TB drives inside. My intention is to use it as a backup for an 8TB RAID volume (also consisting of four 2TB drives); copying the entire disk over every weekend.

Its plugged in via USB, and came with no driver disk. The problem: when I try to convert the disks from basic to dynamic, I get an error 'This operation is not supported by the object'. Also, it will not let me convert the four drives into an 8TB spanned volume; I just get the same error.

When I mailed the manufacturer, they replied:

'This device is JBOB only. You cannot not use this with a RAID setup'

But surely if I'm just backing up it needs no RAID functions? I just need a straight copy.

My first guess would be to try connecting with ESATA instead (the enclosure can use both), but the machine has no port for it. Alternatively, maybe there is software which will just do a straight copy of each 2TB disk to each disk in the enclosure?

Any other ideas?

Many thanks.

m
0
l
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