On Jul 21, 2009, at 3:00 PM, Louis-Frédéric Feuillette wrote:
On Tue, 2009-07-21 at 14:45 -0700, Richard Elling wrote:
But to put this in perspective, you would have to *delete* 20
GBytes of
data a day on a ZFS file system for 5 years (according to Intel) to
reach the expected endurance.
Forgive my ignorance, but is this not exactly what a SSD ZIL does? A
ZIL
would need to "delete" it's data when it flushes to disk. I know this
thread is about consumer SSDs but are the enterprise SSDs that much
better in terms of write cycles (not speed, I know they differ in some
cases dramatically).
Good question. I don't know of a sync workload that does that sort
of traffic where I would only use one SSD, but I suppose it is possible.
Yes, SSDs can vary in several ways:
1. the space reserved for endurance (spares)
2. ECC algorithms
3. failure management algorithms
4. DRAM buffers
5. SLC:MLC ratios
6. page size
7. quality of components
Some of these are closely guarded secrets, so resorting to black box
testing may be the best you can hope for. But even black box testing
can be difficult because the failure rate is so low, especially in early
life, that the confidence is low. Black boxes with a more consistent
(and low) failure rate are easier to get high confidence in their
failure
behaviours.
It will be interesting to see what happens over time :-)
Richard, do you have a blog post about SSDs that I missed in my
travels?
I think there are a few on my todo list... :-)
-- richard
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
