On Thu, Sep 14, 2023 at 02:36:40PM +0200, cem@xxxxxxxxxx wrote:
> From: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
>
> The current output message prints out a suggestion of an AG size to be
> used in lieu of the user-defined one.
> The problem is this suggestion is printed in filesystem blocks, while
> agsize= option receives a size in bytes (or m, g).
Hmmm. The actual definition of the parameter in mkfs.xfs has
".convert = true", which means it will take a value in filesystem
blocks by appending "b" to the number.
i.e. anything that is defined as a "value" with that supports a
suffix like "m" or "g" requires conversion via cvtnum() to turn it
into a byte-based units will also support suffixes for block and
sector size units.
Hence "-d agsize=10000b" will make an AG of 10000 filesystem blocks
in size, or 40000kB in size if the block size 4kB....
# mkfs.xfs -f -dagsize=100000b /dev/vdb
meta-data=/dev/vdb isize=512 agcount=42, agsize=100000 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1 bigtime=1 inobtcount=1 nrext64=0
data = bsize=4096 blocks=4194304, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=16384, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
Discarding blocks...Done.
#
> This patch tries to make user's life easier by outputing the suggesting
> in bytes directly.
>
> Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
> ---
> mkfs/xfs_mkfs.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index d3a15cf44..827d5b656 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -3179,9 +3179,11 @@ _("agsize rounded to %lld, sunit = %d\n"),
> if (cli_opt_set(&dopts, D_AGCOUNT) ||
> cli_opt_set(&dopts, D_AGSIZE)) {
> printf(_(
> -"Warning: AG size is a multiple of stripe width. This can cause performance\n\
> -problems by aligning all AGs on the same disk. To avoid this, run mkfs with\n\
> -an AG size that is one stripe unit smaller or larger, for example %llu.\n"),
> +"Warning: AG size is a multiple of stripe width. This can cause performance\n\
> +problems by aligning all AGs on the same disk. To avoid this, run mkfs with\n\
> +an AG size that is one stripe unit smaller or larger,\n\
> +for example: agsize=%llu (%llu blks).\n"),
> + (unsigned long long)((cfg->agsize - dsunit) * cfg->blocksize),
> (unsigned long long)cfg->agsize - dsunit);
> fflush(stdout);
> goto validate;
I have no problem with the change, though I think the man page needs
updating to remove the "takes a value in bytes" because it has taken
a value that supports all the suffix types the man page defines
for quite a long time....
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
