Thank you for your reply. I had read the blog. The most interesting thing is WHY is there no performance improve when it set any compression? The compressed read I/O is less than uncompressed data, and decompress is faster than compress. so if lzjb write is better than non-compressed, the lzjb read would be better than write?
Is the ARC or L2ARC do any tricks? Thanks ________________________________ From: David Pacheco <david.pach...@sun.com> To: Chookiex <hexcoo...@yahoo.com> Cc: zfs-discuss@opensolaris.org Sent: Wednesday, June 24, 2009 4:53:37 AM Subject: Re: [zfs-discuss] Is the PROPERTY compression will increase the ZFS I/O throughput? Chookiex wrote: > Hi all. > > Because the property compression could decrease the file size, and the file > IO will be decreased also. > So, would it increase the ZFS I/O throughput with compression? > > for example: > I turn on gzip-9，on a server with 2*4core Xeon, 8GB RAM. > It could compress my files with compressratio 2.5x+. could it be? > or I turn on lzjb, about 1.5x with the same files.. It's possible, but it depends on a lot of factors, including what your bottleneck is to begin with, how compressible your data is, and how hard you want the system to work compressing it. With gzip-9, I'd be shocked if you saw bandwidth improved. It seems more common with lzjb: http://blogs.sun.com/dap/entry/zfs_compression (skip down to the results) -- Dave > > could it be? Is there anyone have a idea? > > thanks > > ------------------------------------------------------------------------ > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss -- David Pacheco, Sun Microsystems Fishworks. http://blogs.sun.com/dap/
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