ZFS write speed

[S.N.Grigoriev]

29.10.10, 07:14, "jhell" <jhell at DataIX.net>:

> On 10/28/2010 03:30, S.N.Grigoriev wrote:
>  > 
>  > 
>  > 28.10.10, 01:54, "Stefan Bethke" :
>  > 
>  >> Am 27.10.2010 um 22:51 schrieb S.N.Grigoriev:
>  >>  
>  >>  > Hi list,
>  >>  > 
>  >>  > I've got very low write speed using ZFS on a SATA disk.
>  >>  > My HDD configuration is:
>  >>  > ad4: 70911MB  at ata2-master UDMA100 SATA 3Gb/s
>  >>  > ad6: 78532MB  at ata3-master UDMA100 SATA 1.5Gb/s
>  >>  > ad8: 1430799MB  at ata4-master UDMA100 SATA 3Gb/s
>  >>  
>  >>  The EARS has 4k sectors, if I'm not mistaken.  I don't recall the eventual
>  >>  outcome, but there was a long thread on stable or hackers on how to ensure
>  >>  proper alignment and (minimun) 4k-sized writes to make sure the disk doesn't
>  >>  have to do a read-modify-write cycle, so try and search the archives.
>  
>  Though this might play a small part in your write performance with the
>  EARS drives, this issue has more to do with the stat() calls and the ACL
>  involvement with ZFS. This was sort of solved in 8.1-STABLE and from 3
>  cases that I know about and 1 being my own... write/read speeds have
>  doubled from what can be seen to an effect of 8.1-RELEASE.
>  
>  You may want to either upgrade to stable/8 or use one of the snapshots
>  from here:
>  
>  ftp://ftp.freebsd.org/pub/FreeBSD/snapshots/201010/
>  

thank you. I'll be experimenting with STABLE next week.  

-- 
Regards,
S.Grigoriev.