The "too slow" drive is cast out, and the array continues with only one drive.īack in "ordinary drive" land, this inability to read the data is NOT solvable, because there is no way to know what data that block is supposed to contain, except to read it, which has already been tried 1000 times and failed. The problem with a mirrored RAID is that 10*10*10 retries takes a palpable amount of TIME (nearly a quarter minute in some cases) and this simply breaks the array. if no good data after all that, error -36 I/O Error is generated.
SOFTRAID SLOW READ SOFTWARE
That software asks the lower level software to do a re-read.
![softraid slow read softraid slow read](https://www.fatalerrors.org/images/blog/a13d4065f2496786e41a45383faf0cff.jpg)
The an error is passed to the higher-level software. This is what can cause the clicking sound on same drives when data are going bad. If the data do not come clean, it reports an error back to the low-level driver, which will request a re-read, and if good data are not obtained the software may ask drive controller to do a recalibrate (seek track 00) where there is a switch confirming the track location. If an error was detected, the drive controller does a re-read of the data, in an attempt to get good data. The raw data, including the check bits, are fed through the data separator and in almost all cases, good data comes out the other side, with no indication of an error. This seems like my best option but before buying it I wanted to make sure there isn't a free build in alternative.Įach and every read from a disk drive is done using error correction hardware. I saw that OWC sells software "SoftRAID" that is well rated.
SOFTRAID SLOW READ PRO
The other issue with a card in general, the mac pro has hard drive trays that slide into the motherboard, making it problematic to run sata power and data cables to the drives.
![softraid slow read softraid slow read](https://www.cs.utexas.edu/~scottm/cs314/javacode/A10_Huffman/images/slowReadOption.jpg)
Which leads me to the following questions: I read that Apple has taken away the raid features in some versions of the OS, I'm using Yosemite 10.10.5 but I'm not sure if this is the reason or if it's something else. The tutorials refer to a raid Tab that isn't visible in my Disk Utility (v13). I'm confused because when I initial researched it seemed like all I would need to buy two hard drives and use Apple's Disk Utility to create the array. I wanted build an internal Raid for my 2009 Mac Pro.