[zfs-discuss] ZPOOL import dangerous bug in the latest 6.5.4-1

Richard Laager rlaager at wiktel.com
Sat Feb 13 22:25:51 EST 2016

On 02/12/2016 02:01 PM, Chris Siebenmann wrote:
>as far as I can see, the hostid is eight bytes, not four.

> [*: specifically it is ZPOOL_CONFIG_HOSTID aka "hostid", which is
>      defined as an unsigned 64-bit int.]

While ZPOOL_CONFIG_HOSTID is 64-bits, spl only ever returns 32-bits from 
/etc/hostid. See module/spl/spl-generic.c, specifically the end of 

Setting a 64-bit hostid on the kernel command-line (spl.spl_hostid) also 
results in it being truncated to 32-bits. I'm not 100% sure where that's 
happening, but I confirmed it by testing.


More information about the zfs-discuss mailing list