Rubbish Maplin USB SDHC RAID Enclosure

prowla

I bought one of these during the week; it takes 4 SD cards and, according to the box, works as RAID-0 or JBOD.

But it doesn't.

I wanted it for JBOD (just a bunch of disks), so that I could see each SD card as a separate disk, but there is nowhere to configure that and there are no instructions to say how to.

It'll be going back for a refund.

smos585

why not go to the maplin website, find the item, and click on "ask a question", usually they can resolve the issue. Alternatively, in our local store there is a guy that can answer most questions.

neilwoods

JBOD in this case doesnt actually allow you to use each disk independently, just allows you to use different size cards to combine into a single drive.

System

prowla wrote: »

I bought one of these during the week; it takes 4 SD cards and, according to the box, works as RAID-0 or JBOD.

But it doesn't.

I wanted it for JBOD (just a bunch of disks), so that I could see each SD card as a separate disk, but there is nowhere to configure that and there are no instructions to say how to.

It'll be going back for a refund.

You misunderstand JBOD.
JBOD is where a bunch of disks is presented as a single disk. It is not intended to show each disk separately. It is doing what it was designed to do

googler

The summary on the Maplin page says;

"Combine multiple Secure Digital cards into one large mass storage device"

which doesn't even hint that you can use them separately.....

bengalknights

As others have stated JBod does the opposite of what you want to do.

To have them listed as seperate drives you would need seperate enclosures or a multi adaptor

prowla

!!!!!! wrote: »

You misunderstand JBOD.
JBOD is where a bunch of disks is presented as a single disk. It is not intended to show each disk separately. It is doing what it was designed to do

bengalknights wrote: »

As others have stated JBod does the opposite of what you want to do.

To have them listed as seperate drives you would need seperate enclosures or a multi adaptor

No, it is you who is wrong - JBOD is where it presents as a bunch of disks, hence the term; RAID is where it combines them to present a larger drive.

Search for the topic in google - you'll find the answer (eg. this wiki link).

The packet the thing came in says JBOD.

prowla

googler wrote: »

The summary on the Maplin page says;

"Combine multiple Secure Digital cards into one large mass storage device"

which doesn't even hint that you can use them separately.....

The Maplin page says "Supports RAID 0 and JBOD".

neilwoods

JBOD (for "just a bunch of disks," or sometimes "just a bunch of drives") is a derogatory term - the official term is "spanning" - used to refer to a computer's hard disks that haven't been configured according to the RAID (for "redundant array of independent disks") system to increase fault tolerance and improve data access performance.

The RAID system stores the same data redundantly on multiple disks that nevertheless appear to the operating system as a single disk. Although, JBOD also makes the disks appear to be a single one, it accomplishes that by combining the drives into one larger logical one. JBOD doesn't deliver any advantages over using separate disks independently and doesn't provide any of the fault tolerance or performance benefits of RAID.

Notice the words in red single one, as in single drive.

For a more detailed explanation read the below.

http://www.msexchange.org/articles_tutorials/exchange-server-2010/high-availability-recovery/what-actually-is-jbod-how-might-used-exchange-2010.html

prowla

neilwoods wrote: »

JBOD (for "just a bunch of disks," or sometimes "just a bunch of drives") is a derogatory term - the official term is "spanning" - used to refer to a computer's hard disks that haven't been configured according to the RAID (for "redundant array of independent disks") system to increase fault tolerance and improve data access performance.

The RAID system stores the same data redundantly on multiple disks that nevertheless appear to the operating system as a single disk. Although, JBOD also makes the disks appear to be a single one, it accomplishes that by combining the drives into one larger logical one. JBOD doesn't deliver any advantages over using separate disks independently and doesn't provide any of the fault tolerance or performance benefits of RAID.

Notice the words in red single one, as in single drive.

For a more detailed explanation read the below.

http://www.msexchange.org/articles_tutorials/exchange-server-2010/high-availability-recovery/what-actually-is-jbod-how-might-used-exchange-2010.html

That is (as the wiki page I linked to says) an incorrect use of the term JBOD, and JBOD is not a derogatory term for spanning - it is something quite different and specific. If you actually look behind that the writer of the exchange site is saying, they are saying that you can use the OS to combine JBOD disks onto a concatenated device.

JBOD means each disk is presented individually (and the icon on the box shows each SD card with a separate connection out of it). The term "Just A Bunch Of Disks" means just that.

Spanning, or concatenation, is amaglamating multiple drives end-to-end as if they were a larger drive.If a disk fails then that portion of the data is lost.

RAID 0 (which is what this unit purports to do) is simply striping of data across multiple disks to improve performance.If a disk fails, all of the data on i is lost, and the information across the others cold be corrupted. You are wrong to say that the unit's RAID operation incorporates redundancy - it is RAID 0.

RAID 1 is mirroring, and each block is replicated to another disk.If a disk fails, all of its data is available on another disk.

RAID 5 is a mathematically based method where there are N+1 disks, where the "+1" sorest the result of a parity cacluation. If any disk fails then the data can be reconstructed by applying the calculation.

In my work I deal with data centre systems that have external (typically SAN) storage, and we use a selection of RAID 5, RAID 0/1 and JBOD presented storage. With JBOD we may use the OS (eg. LVM, ZFS) or add-on system tools (eg.Veritas) to do software RAID.

neilwoods

You work with network storage and you rely on wiki for answers ? ok