Document the new --write-zeroes option in the manpage. Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> Acked-by: Kinga Tanska <kinga.tanska@xxxxxxxxxxxxxxx> Reviewed-by: Xiao Ni <xni@xxxxxxxxxx> Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx> Acked-by: Coly Li <colyli@xxxxxxx> --- mdadm.8.in | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/mdadm.8.in b/mdadm.8.in index 64f71ed1df43..6f0f6c13baf1 100644 --- a/mdadm.8.in +++ b/mdadm.8.in @@ -837,6 +837,22 @@ array is resynced at creation. From Linux version 3.0, .B \-\-assume\-clean can be used with that command to avoid the automatic resync. +.TP +.BR \-\-write-zeroes +When creating an array, send write zeroes requests to all the block +devices. This should zero the data area on all disks such that the +initial sync is not necessary and, if successfull, will behave +as if +.B \-\-assume\-clean +was specified. +.IP +This is intended for use with devices that have hardware offload for +zeroing, but despite this zeroing can still take several minutes for +large disks. Thus a message is printed before and after zeroing and +each disk is zeroed in parallel with the others. +.IP +This is only meaningful with --create. + .TP .BR \-\-backup\-file= This is needed when @@ -1370,7 +1386,7 @@ and .B layout\-alternate options are for RAID0 arrays with non-uniform devices size that were in use before Linux 5.4. If the array was being used with Linux 3.13 or -earlier, then to assemble the array on a new kernel, +earlier, then to assemble the array on a new kernel, .B \-\-update=layout\-original must be given. If the array was created and used with a kernel from Linux 3.14 to Linux 5.3, then -- 2.30.2
