On Sat, 19 Jun 2010, Arne Jansen wrote:
If the ZIL is heavily used, the same 10% of the device get written over and over again, reducing the life span by 90%.
The SSD design might implement wear leveling which moves an old block which was only written once or twice to the block with heavy wear. The offsets to the two blocks would then be logically swapped. This seems like a reasonable design choice since some blocks are virtually read-only. The SSD is not necessarily restricted to only writing blocks on request of the user.
Is there some fundamental flaw in this line of thought?
No. Normally you would not want to use a MLC SSD as a slog. The SLC SSDs wear out quicker than one would like under heavy repeated writes. Over-provisioning the slog SSD storage size should help.
Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
