What is concatenated raid
Depending on the application, different interlace values can increase performance for your configuration. RAID 5 volumes also use an interlace value. When you create a stripe, you can set the interlace value or use the Solaris Volume Manager default interlace value of 16 Kbytes.
Once you have created the stripe, you cannot change the interlace value. However, you could back up the data on it, delete the stripe, create a new stripe with a new interlace value, and then restore the data.
Figure 7—1 shows a stripe that is built from three components disks. The interlace value sets the size of each chunk. The total capacity of the stripe d2 equals the number of components multiplied by the size of the smallest component. If each slice in the following example were 2 Gbytes, d2 would equal 6 Gbytes. A concatenated volume, or concatenation, is a volume whose data is organized serially and adjacently across components, forming one logical storage unit.
Use a concatenation to get more storage capacity by combining the capacities of several components. You can add more components to the concatenation as the demand for storage grows.
A concatenation enables you to dynamically expand storage capacity and file system sizes online. With a concatenation you can add components even if the other components are currently active. To increase the capacity of a stripe, you need to build a concatenated stripe.
A concatenation can also expand any active and mounted UFS file system without having to bring down the system. In general, the total capacity of a concatenation is equal to the total size of all the components in the concatenation. If a concatenation contains a slice with a state database replica, the total capacity of the concatenation would be the sum of the components minus the space that is reserved for the replica. You can also create a concatenation from a single component. Later, when you need more storage, you can add more components to the concatenation.
Figure 7—2 illustrates a concatenation that is made of three components slices. The data blocks, or chunks, are written sequentially across the components, beginning with Disk A. Disk A can be envisioned as containing logical chunks 1 through 4. Logical chunk 5 would be written to Disk B, which would contain logical chunks 5 through 8. Logical chunk 9 would be written to Drive C, which would contain chunks 9 through The total capacity of volume d1 would be the combined capacities of the three drives.
If each drive were 2 Gbytes, volume d1 would have an overall capacity of 6 Gbytes. Open Disk Utility for me. You can combine multiple hard disks into a striped RAID set to provide faster disk access.
For example, in a striped RAID set composed of three disks, data is distributed between all the disks and three disks write and read that data simultaneously, giving you faster access. A striped RAID set is especially useful for quickly accessing large files, such as digital video and database files.
A striped RAID set works best if the disks are about the same size and are connected to your computer via fast connections. If the disks are different sizes, a striped RAID set treats all the disks as if they are the size of the smallest one. If the disks are connected to the computer with slow connections, such as USB connections, you might not get faster disk access with a striped RAID set.
Striped RAID is a bit similar in that the controller sends data to each disk in the array in turn until all the data has been sent out. Loading page content. Reply Helpful 1 Thread reply - more options Link to this Post. May 27, AM in response to Malcolm Rayfield In response to Malcolm Rayfield With concatenated, the first drive has the lower numbered blocks, the second the higher numbered blocks. Whate are blocs? With striped, all disk operations will go at twice the transfer rate if they involve more than one That was my understanding.
With either striped or concatenated, if And with a stripped RAID of more than 2 drives let's say 3 , how's the data split? Or maybe you need even drive number 4 drives? And is it possible to add a 3rd drive to a stripped or concatanated RAID after the fact I mean, when you need more space? Reply Helpful Thread reply - more options Link to this Post. Do you know if a stripped RAID array could grow by addind a new drive to an existing array without having to reformat the drives? Going back to my card analogy, if someone else sits down in the game, you have to deal the hand once more.
Hence the data will have to be backed up and restored after the drive is added to the array. I going to flog this card analogy for all it is worth!