zfs/cmd/zdb
Robert Novak bfcbec6f5d
Add block histogram to zdb
The block histogram tracks the changes to psize, lsize and asize
both in the count of the number of blocks (by blocksize) and the
total length of all of the blocks for that blocksize.  It also
keeps a running total of the cumulative size of all of the blocks
up to each size to help determine the size of caching SSDs to be
added to zfs hardware deployments.

The block history counts and lengths are summarized in bins
which are powers of two. Even rows with counts of zero are printed.

This change is accessed by specifying one of two options:

zdb -bbb pool
zdb -Pbbb pool

The first version prints the table in fixed size columns.
The second prints in "parseable" output that can be placed into
a CSV file.

Fixed Column, nicenum output sample:
  block   psize                lsize                asize
   size   Count Length   Cum.  Count Length   Cum.  Count Length   Cum.
    512:  3.50K  1.75M  1.75M  3.43K  1.71M  1.71M  3.41K  1.71M  1.71M
     1K:  3.65K  3.67M  5.43M  3.43K  3.44M  5.15M  3.50K  3.51M  5.22M
     2K:  3.45K  6.92M  12.3M  3.41K  6.83M  12.0M  3.59K  7.26M  12.5M
     4K:  3.44K  13.8M  26.1M  3.43K  13.7M  25.7M  3.49K  14.1M  26.6M
     8K:  3.42K  27.3M  53.5M  3.41K  27.3M  53.0M  3.44K  27.6M  54.2M
    16K:  3.43K  54.9M   108M  3.50K  56.1M   109M  3.42K  54.7M   109M
    32K:  3.44K   110M   219M  3.41K   109M   218M  3.43K   110M   219M
    64K:  3.41K   218M   437M  3.41K   218M   437M  3.44K   221M   439M
   128K:  3.41K   437M   874M  3.70K   474M   911M  3.41K   437M   876M
   256K:  3.41K   874M  1.71G  3.41K   874M  1.74G  3.41K   874M  1.71G
   512K:  3.41K  1.71G  3.41G  3.41K  1.71G  3.45G  3.41K  1.71G  3.42G
     1M:  3.41K  3.41G  6.82G  3.41K  3.41G  6.86G  3.41K  3.41G  6.83G
     2M:      0      0  6.82G      0      0  6.86G      0      0  6.83G
     4M:      0      0  6.82G      0      0  6.86G      0      0  6.83G
     8M:      0      0  6.82G      0      0  6.86G      0      0  6.83G
    16M:      0      0  6.82G      0      0  6.86G      0      0  6.83G

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Robert E. Novak <novak5@llnl.gov>
Closes: #9158 
Closes #10315
2020-06-26 15:09:20 -07:00
..
.gitignore Add .gitignore files to exclude build products 2010-01-08 11:35:17 -08:00
Makefile.am OpenZFS restructuring - libspl 2019-10-02 10:39:48 -07:00
zdb.c Add block histogram to zdb 2020-06-26 15:09:20 -07:00
zdb.h OpenZFS 8081 - Compiler warnings in zdb 2017-10-27 12:46:35 -07:00
zdb_il.c OpenZFS 9166 - zfs storage pool checkpoint 2018-06-26 10:07:42 -07:00