▁comparison ▁of ▁the ▁version ▁of ▁the ▁ex F AT ▁file ▁system ▁by ▁the ▁driver ▁to ▁make ▁sure ▁the ▁driver ▁is ▁compatible ▁with ▁the ▁file ▁system ▁it ▁is ▁trying ▁to ▁mount , ▁and ▁to ▁make ▁sure ▁that ▁none ▁of ▁the ▁required ▁directory ▁records ▁are ▁missing ▁( for ▁example , ▁the ▁directory ▁record ▁for ▁the ▁up case ▁table ▁and ▁Al location ▁Bitmap ▁are ▁required ▁and ▁the ▁file ▁system ▁can ' t ▁run ▁if ▁they ▁are ▁missing ). ▁If ▁any ▁of ▁these ▁checks ▁fail , ▁the ▁file ▁system ▁should ▁not ▁be ▁mounted , ▁although ▁in ▁certain ▁cases ▁it ▁may ▁mount ▁read - only . ▁ ▁The ▁file ▁system ▁provides ▁extens ibility ▁through ▁template - based ▁metadata ▁definitions ▁using ▁generic ▁layout s ▁and ▁generic ▁patterns . ▁ ▁Flash ▁optim izations ▁ ▁ex F AT ▁contains ▁a ▁few ▁features ▁that , ▁according ▁to ▁Microsoft , ▁makes ▁it ▁flash - friend ly : ▁ ▁B ound ary ▁alignment ▁for ▁filesystem ▁structures . ▁The ▁off sets ▁for ▁the ▁F AT ▁and ▁the ▁cluster ▁heap ▁is ▁adjust able ▁at ▁format - time , ▁so ▁that ▁writes ▁to ▁these ▁areas ▁will ▁happen ▁in ▁as ▁few ▁flash ▁blocks ▁as ▁possible . ▁ ▁An ▁" O EM ▁Param eters " ▁field ▁can ▁be ▁used ▁to ▁record ▁features ▁such ▁as ▁block ▁size ▁of ▁the ▁underlying ▁storage . ▁ ▁The ▁lack ▁of ▁a ▁journal , ▁so ▁that ▁less ▁data ▁are ▁written ▁ ▁However , ▁Microsoft ' s ▁own ▁implementation ▁on ▁Windows ▁is ▁not ▁truly ▁optimized ▁for ▁flash ▁drives . ▁The ▁O EM ▁parameters ▁are ▁ignored ▁by