RAID JBOD
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Job Bunch of Disks are a series of disks configured so that they act as a single disk.  Technically they are not a RAID because there is no redundancy, but of of convience, they are refered to as RAIDs.


CnW allows the user to select phyiscal areas of the disk and then trat them as a logical device.  The simplest configuration would be just appending the second (and third) disks to each previous one.  Each disk can be set to have a logical stripe, and the length of the stripe.  A stripe need not fill a disk, and there can be multiples stripes on a disk, not necessarily in sequence.  The example shown below is based on a Broadcom NAS Version 1.1 set of disks




With a Broadcom disk the setup was as follows.

The parameters are set as above

When the drive was selecteds RAID, Sector 0 will; display the string "BrcmSeMagicStr".  Sector 0x80 will then show the Reiser SuperBlock with ReIsEr2Fs starting in byte 0x34.  It may be necessary to set the partition to Reiser in the partitions option screen.


The Broadcom values are extracted for sector 0x1 (starting at 0x0)


00000000   00 00 00 00 00 00 00 0A - 00 00 00 00 00 02 00 00                  

00000010   00 00 00 00 00 02 00 0C - 00 00 00 00 00 02 00 00                 

00000020   00 00 00 00 00 13 42 50 - 00 00 00 00 22 DB 7E E0         BP    "~

00000030   00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00                   


The dump above is for the first disk and the start sector in row 2 is 0x134250  with a length of 0x22DB7EE0.  The first 2 start and length values are for control data, rather than user data


For disk two, there have been a few variations seen


00000000   00 00 00 00 00 0F 42 4C - 00 00 00 00 01 2A 05 F2         BL    *

00000010   00 00 00 00 3A 44 6B 92 - 00 00 00 00 1D 0F FB 5E        :Dk    ^

00000020   00 00 00 00 01 39 48 40 - 00 00 00 00 39 09 D0 D4        9H@    9


The data above apparently has three sections, but from experimentation the first one was not used.  On another disk seen, the second disk had only a single section of data, with it's data in the first 16 bytes of sector 2



Volume Start


The volume start is normally set to zero but on some RAID system, the RAID configuration starts at a certain sector.  Typically, all sectors before this point are RAID-1, ie mirrored between drives.


Concatenate drives


This option is a quick way to set up drives that are appended to each other.  It assumes that all of the first drive is accessed, followed by the second drive, and maybe third drive.  In these cases the stripe value is always 1.


Analyse Media vault..


The analyse feature is currently for HP Media Vault disks.  It will try and configure the disks and section starts based on the meta data stored on the drives