[illumos-Developer] illumos bug 453

Deano deano at rattie.demon.co.uk
Sun Jan 9 08:24:48 PST 2011


I have a fix for bug 453 ready to be checked in. 

Its adds an optional parameter to zpool, such that you can specify the drive
block size, normally this isn't needed as ZFS reads it from the drive itself
but recently a number of SATA 4KiB blocks drives have appeared (for >= 2TB
disks), that either lie or don't bother to export the correct size, which
can cause performance issues as they are classed as 512B drives by default.
It is purely a tool level fix, as ASHIFT setting (which it ultimately is) is
already supported fully by ZFS properties just not exposed to the zpool

zpool create block-size 4096 dsk1 dsk2

Which will set the block-size for *all* following drives on the command
line. block-size 0 will reset to hw detect, and setting block-size again is
allowed per pool, so that different pools can have different block sizes.

Been reviewed on IRC the other night (I forgot to get the emails of the
reviewers so just have the IRC names (Triskelios, gisburn, jbk), if I can
get the emails I can give proper credit).

Passes hg nit except for copyright year warning, left that because not sure
how illumos as a whole wants to handle copyright update notices. Personally
I don't mind doing it in my name or assigning to illumos or ??

Webrev with results of code reviews and hg nit fixes can be found at

Any problems, just say and I'll get them fixed or if okay would be good to
get it into the code base :)


deano at cloudpixies.com

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