One of the characteristics of some disk arrays and some NAS is that they allow JBOD mode, but what is that JBOD mode? And most importantly, how does it differ from RAIDs?
Table of Contents
Definition
Let's start with the exact definition of JBOD which is Just a Bunch Of Drives or what is the same "Only a lot of records". Although it may seem strange, we will explain it better to make it clear.
How does JBOD work?
It is actually a very simple system, although not widely used, and JBOD does not have data redundancy as RAID systems do, which we will talk about in this post explaining what they are. RAID systems.
In JBOD each disk is independent, which means that if a disk crashes, all the contents of that disk are lost, but the unit will continue to work with the rest of the disks. Here below I add the JBOD band scheme.
In this diagram we can see a JBOD of 3 hard drives. If each one is 1TB we will have a unit in the 3TB OS, let's call it D:
If disk 1 breaks, we will only lose the data on that disk. Even so, drive D: will still work but with only 2TB of disk 0 and 2
The JBOD system that I have shown you in the diagram is the most used, and if a disk breaks, since it is independent, you can try to recover the information in a simple way. This does not happen with RAID systems that require all the disks and the specific controller for data recovery.
Differences between JBOD and RAID
Surely if you know something about RAID systems, you will know that one of the benefits of them is the level of redundancy in the data, something that in JBOD is non-existent. But you will also know that one of the negative points is that we lose storage capacity, except in RAID 0, and this in JBOD does not happen ( we will talk about ZFS formatsTherefore JBOD has some advantages and disadvantages over RAID systems.
I want to take advantage of it to explain the difference with RAID 0 since, from what was written above, confusion could occur.
While RAID 0 divides the data by the number of disks, JBOD does not, and therefore when a RAID 0 crashes all the data on the drive is lost. JBOD handles this best with its ability to use disks independently.
What uses does JBOD have?
This is one of the most difficult questions to answer, since in large companies JBOD does not make much sense due to the lack of redundancy, and JBOD is not something particularly used. Until 3 weeks ago when CHIA COIN ECHOES arrived.
CHIA COIN miners are becoming famous for disc cabins JBOD like the one I show you here.
This unit of the German EUROstore In its models of 60 and 102 units, it is one of the most purchased, and it is that to save the PLOTTS generated to farm, CHIA COIN is one of the best and with greater capacity.
For the connection we will need a PCI SAS HBAs controller that has up to 12 external SAS ports, since the 102-unit model contains 12 SAS ports in 4 HOST controllers.
Conclusion
Although JBOD has pros and cons and its use is not very common in home or small business environments, in large companies things change a lot. This is thanks to the use of the SUN file system, ZFS, which can give you a certain level of redundancy in storage POOLS, but this is only for large data centers.
But before the arrival of the cryptocurrency CHIA COIN, JBOD systems have come to the fore for those people who want to mine the currency and look for these disk cabinets. Since JBOD offers them what they are looking for: the largest storage capacity without losing anything in redundancy bands.
And what do you think, have you ever tried a JBOD team? We await your answers in the comments.
