Salut, for housing a debian chroot in my android phone, I want to set up a 2.5G partition on this new micro sd card. For that, I want to figure out which parameters to give to mke2fs, as in
mkfs.ext4 -E stride=2,stripe-width=2048 -L debian_chroot /dev/sdb2
Now to figure out the internal erase block size, flashbench was recommended. But I can not quite make sense of my result..
# fdisk.distrib -l /dev/sdb
Disk /dev/sdb: 15.9 GB, 15931539456 bytes 255 heads, 63 sectors/track, 1936 cylinders, total 31116288 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000604f9
Device Boot Start End Blocks Id System /dev/sdb1 2048 25890815 12944384 b W95 FAT32 /dev/sdb2 25890816 31115263 2612224 83 Linux
# flashbench -va /dev/sdb --blocksize=1024 |(echo "align,pre [µs],on [µs],post [µs],diff [µs]" && sed -r 's/\w+ //g;s/\t/,/g;s/[0-9]+ns*/0/g;s/µs//g')|tee flashbench-16gb-sandisk-extreme-microsdhc-blocksize-1024.csv # flashbench -va /dev/sdb --blocksize=$[3*1024] |(echo "align,pre [µs],on [µs],post [µs],diff [µs]" && sed -r 's/\w+ //g;s/\t/,/g;s/[0-9]+ns*/0/g;s/µs//g')|tee flashbench-16gb-sandisk-extreme-microsdhc-blocksize-$[3*1024].csv
resulting CSV files attached.. I created a spreadsheet chart showing a drop.. does this mean the erasure block size is 128KB?
That would give a stripe-width of 128KB/(2*4KB)=16?
And I have not at all grokked the benefit/applicability of open-au/open-au-nr for practical purposes.. Any clarification greatly appreciated.
#Regards!Marcel
