Le 25/08/2019 à 13:20, Richard Owlett a écrit :
How do I search for answer to my inadequately phrased question below.
1. I assume that sector size is a _TERM_ reserved for something fixed
when the disk is manufactured.
With modern disks, there are two sector sizes :
- the physical sector size, either 512 or 4096 bytes.
- the logical sector size, usually 512 but sometimes 4096 bytes.
This is of course different from the filesystem block size which is a
multiple of the logical sector size, and should be a multiple of the
physical sector size for optimal performance.
2. What is the proper search term to use for something whose dimensions
would be "megabytes/inode"? {I'll use "blob" for now }
This is just a ratio without any actual object associated. It should be
chosen close to the estimated average file size to avoid running out of
inodes when there are still plenty of free blocks or the other way
around. The file size to account for is the "real" on-disk size,
including the unused space in the last block. In short, it is the size
rounded to the next block size boundary.
3. The references I skimmed were focused pretty much on "disk full"
meaning either running out of "inodes" or "physical bytes on disk".
the question:
How find discussion of
blob size v file fragmentation [cf head seeks in spinning rust]
blob size v wear problems on SSD [unclear how that's handled now]
blob size v parameters such as bs when using dd [lousy example]
AFAIK, the inode ratio does not matter for these topics. The disk sector
sizes and filesystem block sizes matter more.
