Recommendation for external hard disk for Mac Pro

Dear "The hatter", Thank you very much for your very valuable comments.

In line with spreading out my future investments, I have been thinking on the following step-wise upgrades:

1. Replace the 120GB OWC Mercury Extreme Pro SSD with the 256GB Samsung 840 Pro SSD

With regard to the other 4 internal HDD, I have been thinking the following options:

Option 1: Replace the two 2TB HDD in bay 3 and 4 and replace with two 4TB HDD in RAID 1 and run Time Machine on it. I know this will not increase the space, but it will increase redundency.

Option 2: Replace all the 4 HDD with 3TB Red or 4TB Black HDDs and create 2 volumes of 3GB or 4GB each in a RAID 5 configuration.

If I choose option 2, I would have 4x2TB RE4 drives free. What if I put it in a IcyDock 4drive enclosure and create a 6GB volume in a RAID 5 configuration to run TimeMachine connected to the MP through eSATA.

I could not find many options for eSATA6 4 drive external drive options.

Gautam

I already use SoftRAID.

Agreed, RAID 1 is not a backup. However, the reason I had set up the 4 internal drives in 2 sets of RAID 0 was for increasing data processing speed and used one set for data and the other as time machine. I realise that having TM in an internal drive volume may not be a good idea, moreover it is also running out of space. My immediate requirement is an external hard drive, probably larger than the 4 GB that a single drive can handle. That is why I am looking for a multi drive enclosure in RAID 6 with eSATA connectivity. I plan to have partitions for cloning my boot drive and that of a couple of other notebooks in the house plus one volume for a multi computer TM. In addition I want to have another 4TB external drive to make a clone of my data disk.

This means, I do not need the two sets of RAID 0 volumes and instead of have a larger single RAID 0 volume across all the 4 internal disks. Presently, I will not need that much space for data, but will give me a big headroom and speed. I note The Hatter's note against striped disks. The other option is to divide the data across the four internal disks- one for photos, one for video, one for other documents and one spare.

I would be glad to get suggestions of multi-drivel enclosures with eSATA. There are not many that I can find in Switzerland. I found the Lacie 4 big Quadra 16TB, effective 8TB in RAID 6.

Replaced my OWC Mercury Extreme Pro with the 256GB Samsung 840 Pro, as suggested by The Hatter.

Now for the external HDD enclosure.

Any experience with the Promise SmartStore DS 4600 enclosure?

I have finally ordered a OWC Mercury Pro Elite QX2 enclosure and will install 4x4 TB HDDs. I plan to use it as a backup drive with multiple volumes to make bootable backups for two Macs and then a large volume for running TM. Data security being my prime concern, of the following 2 available choices which would be the best:

1.RAID 1+0

2.RAID 5 plus 1 spare

Both give the same amount of available space but which one will have better performance and security. QX2 does not have RAID 6 as an option.

Thanks 'The Hatter'. I checked with the technical support and they told me that the drives cannot be mounted independently, hence creating the RAID by Softraid will not be possible. The Qx2 can be setup as a SPAN (one large volume), RAID 0 (2 or 4 drives), RAID 1 (utilizing just 2 drives), RAID 5 (3 or 4 drives) and RAID 10 (4 drives). However, GUID volumes are bootable.