Linux

More on HDs and RAID.

So I have checked this Maxtor drive using all the Maxtor utilities, and the drive seems to pass every one of their tests… I still don’t trust it, mainly since the S.M.A.R.T. feature reports 3925 write errors… And the loss of data I experienced not too long ago…

Anyhoo, I however decided to use it in my RAID 5 array. If the drive does go bad, it will be an easy matter of going to the local computer store, and picking up another 250 gig drive to replace it. With that in mind, I splurged yesterday on 2 removable HD bays (at $14.99 each).

If the drive ever becomes problematic, it will just be a matter of pulling it out, outting a new drive in the tray, putting the tray back in, and rebuilding the drive. Simple.

So I installed the drive to the chain (the maxtor became the slave, since the WD was already on that cable) and booted up the system. The system reported that the WD was now running at DMA-44?? and the Maxtor wasn’t even running with DMA emabled.

WTF!

I pulled the drives out, tried each one individually. All was fine. UDMA-100 and 133 was used by the WD and Maxtor respectively.

To make a long story short, I ended up making the Maxtor master and the WD a slave, which solved the problem.

And onto some RAID issues. With the current implementation of the Linux software RAID, it is currently not possible to grow an array of RAID 5 drives by adding more drives. I’ve read about some patches somewhere, but have not been able to find them. So I decided to rebuild the RAID 5 array now, since I only have about 160 gigs of data.
I want to turn my 3 drive RAID 5 setup, into a 4 drive RAID 5 setup.
First, I am backing up the _really_ important data to another PC on the network (only a few gigs). Then I’m taking the freshly installed HD (Maxtor) and formatting it with one large partition. ReiserFS. I copy everything from the RAID array to this one drive.
I then blow away the RAID setup, and create a new one in the following way.
On 2 drives, create 2 partitions on each, for a total of 4 partitions. That should give me 375 gigs of space. Copy what I have on the curreltly spare drive (Maxtor) back onto the RAID 5 setup.
So far I am using 2 drives (with a RAID setup between 4 partitions) and 2 other drives(not used in the RAID setup).
Ont by one, remove one partition from the RAID 5 array, and replace it with a parttion on a clean drive. Repeat until I end up with 4 drives, with a 125 gig partition on each, and a clean RAID 5 setup. Apparently there is a command that will grow the RAID system to use the entire HD. This way I can hopefully add another drive to the setup.

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