Assuming we start with no state in memory, and have a LFS wi…
Assuming we start with no state in memory, and have a LFS with that looks like the following: how many disk I/Os do we need to perform to read the contents of the directory “/”? block 0: Checkpoint region: imap[0..2] -> 3block 1: [(“.” 0), (“..” 0)] block 2: [size=1,ptr=1,type=d] block 3: [imap: 0->2]
Read DetailsYou see a segment with the following set of writes block…
You see a segment with the following set of writes block 100: [(“.” 0), (“..” 0), (“foo” 1)] block 101: [size=1,ptr=100,type=d]block 102: [(“.” 1), (“..” 0)] block 103: [size=1,ptr=YYY,type=d] block 104: [imap: 0->XXX,1->103] What could be the contents of YYY in the above segment?
Read DetailsYou use a log-based SSD to hold your data. The SSD has 3 bl…
You use a log-based SSD to hold your data. The SSD has 3 blocks with 10 pages per block. Each page holds a single character. The SSD has been used for a while and the current state of the SSD is shown below. The diagram for the SSD contains the following items: FTL mapping logical pages to physical pages block numberpage number (2 lines)state of each page (valid, Erased, or invalid)data stored at each pagean indicator(+) if a page is currently live (has an entry in the FTL)Current State of SSD: FTL 1: 6 2: 10 5: 2 7: 1 8: 20 9: 4 12: 16 13: 9 15: 12 17: 17 18: 5 29: 13 19: 11 20: 14 21: 15 23: 3 24: 18 25: 0 27: 8 28: 7 Block 0 1 2 Page 0000000000 1111111111 2222222222 0123456789 0123456789 0123456789 State vvvvvvvvvv vvvvvvvvvv vEEEEEEEEE Data Ih7tj3UYbK 34quFTEPXg H Live ++++++++++ +++++++++ + Operations that the OS may perform are:write(Logical Address, Data) – storing the data at the logical address read(Logical Address) – reading the data from the logical address trim(Logical Address) – deleting the data from the logical address
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