Solid-negate laborious power If it be critical to make employ of FTL to retain out the logical tackle and the physical tackle between the conversion, if the SSD read, write, delete and other in style work in the case of irregular vitality-down, might perchance perchance perchance reason mapping desk thanks to Too slack to interchange and misplaced There is a fault that the SSD can no longer be known by the diagram.
At the identical time, in picture to crimson meat up read and write performance, customarily employ SDRAM to retain out the cache, if the device of learning and writing encountered irregular vitality-down, SDRAM info would be too slack to write down Nand Flash info loss, or change the mapping desk too slack to write down Nand Flash The mapping desk is lacking.
Habitual vitality failure caused by the phenomenon
SSD irregular vitality failure customarily there are three forms of failure phenomenon:
1, SSD can no longer reproduce the diagram identification, the must rebuild the mapping desk or by straight forward and low capacity to re-manufacturing is more than seemingly used;
2, repeatedly after vitality failure, SSD there are tons of “new rank block”;
The mechanism slack the brand new rank block is that once the SSD reads, writes, or erases unsuccessfully, this might perchance occasionally be identified as a rank block. Clearly, these blocks are no longer truly rank blocks, just correct because they are irregular Energy failure caused by the inferior judgment.
3, SDRAM info loss;
Commonplace vitality-down protection mechanism
Every vitality-down protection mechanism to admire a form of, a form of for the patron, the protection mechanism is completely a form of, in overall there might perchance perchance perchance well be the following two practices:
1, establish your total info in SDRAM
Habitual vitality-down, SDRAM all info wants to be fully written to Nand Flash, in in style, SDRAM capacity is determined to 1000% of the amount of SSD naked capacity, for minute capacity SSD, SDRAM must write Nand Flash info Pretty minute, thru the gigantic capacitor or tantalum capacitor can proceed to write down info. Then again, if the SSD capacity is gigantic sufficient, let’s bear in mind: 8TB, then, SDRAM must write Nand Flash info shall be very gigantic, if easy rely on gigantic capacitor or tantalum capacitor to retain out vitality provide, will inevitably face the following three subtle discipline:
a, the want for extra tantalum capacitor particles to retain out the protection, in the genuine engineering follow, it is a ways a truly excessive test, the engineers face the thickness, the customary dimension limit, PCB house is no longer sufficient to make employ of;
b, although there might perchance be sufficient capacitance to retain out the protection, when the implementation of the “restart”, the SSD will no longer launch smartly, it be critical to first shut down for a whereas sooner than restarting, because: SSD must put your total tantalum capacitor after vitality Known;
c, when the usage of a pair of years after the tantalum capacitor or gigantic capacitor after ageing, when the tantalum capacitor vitality provide can no longer carry out the preliminary produce target mark, the patron easy has info loss after vitality loss or SSD can no longer identify the functionality risks, if the preliminary produce That’s, to retain out redundant capacitors, then, will return to the topic “b” loss of life cycle.
It is a ways gratifying that the complications of b and c are most titillating solutions to solve these thorny complications easiest want the engineers sufficient thoughts and skills easiest.
2, easiest establish the SDRAM consumer info, with out saving the mapping desk
This can nick the usage of SDRAM and the usage of tantalum capacitors, “carry out no longer establish the mapping desk” does now not mean that the mapping desk is misplaced, just correct carry out no longer establish the final info write change diagram, when the SSD re-vitality, Procuring for the final mapping desk to identify the brand new info written to re-produce the mapping desk, the drawbacks of this means is no longer sufficient mechanism to field the cheap, then rebuild the mapping desk shall be longer, SSD takes a whereas to in style receive admission to to in style
For controllers with out SDRAM produce, all info is written all of a sudden to Nand Flash. When info is misplaced, the info that is never in any respect times written to Nand Flash shall be returned to the host. If no extra info wants to be saved, Excessive reliability requirements of the applying, no SDRAM produce is king, its representative is a German industrial heed master, its easiest downside is that the performance is no longer factual sufficient, truly, many positive aspects and the want for the final observe performance, and Is “sufficient” performance.
Take a look at suggestions and solutions
Affirm test, SSD want as a diagram disk and as a disk from the two conditions of testing, so the fundamental disk and carry out from the disk test methodology is the final observe distinction is that the fundamental disk must test the pc to vitality off the machine , and from the disk easiest SSD is more than seemingly on the vitality off.
a, respectively, of the SSD as a blank disc, info is written in the 25% and 50% when writing info, the write info for 85% and 3000, respectively, the irregular vitality down 100% test write info, every down And the vitality-on time interval of 3 seconds;
The precept of writing a form of capacity info to the disk is: When the SSD write a definite amount of info, the background began to garbage collection, garbage collection capacity that the relocation of info, info migration capacity that the mapping desk updates, at the present Habitual vitality failure in overall is a discipline.
b, when the in style write info, the SSD irregular vitality-down
c, when the info is deleted when the irregular vitality-down
Within the dwelling windows, delete the info additionally must execute eight actions, and the institution of the identical document, the mapping desk additionally must change.
d, when the SSD read file is irregular vitality down, test 3000 instances, vitality off time interval of 3 seconds;
e, when the in style shutdown course of irregular vitality down, test 3000 instances;
f, when the in style launch of the working diagram irregular vitality down, test 3000 instances;