On 2/6/2011 3:51 AM, Orvar Korvar wrote:
Ok, so can we say that the conclusion for a home user is:
1) Using SSD without TRIM is acceptable. The only drawback is that without
TRIM, the SSD will write much more, which effects life time. Because when the
SSD has written enough, it will break.
I dont have high demands for my OS disk, so battery backup is overkill for my
needs.
So I can happily settle for the next gen Intel G3 SSD disk, without worrying
the SSD will break because Solaris has no TRIM support yet?
Yes. All modern SSDs will wear out, but, even without TRIM support, it
will be a significant time (5+ years) before they do. Internal
wear-leveling by the SSD controller results in an expected lifespan
about the same as hard drives.
TRIM really only impacts performance. For the ZFS ZIL use case, TRIM has
only a small impact on performance - SSD performance for ZIL drops off
quickly from peak, and supporting TRIM would only slightly mitigate this.
For home use, lack of TRIM support won't noticeably change your
performance as a ZIL cache or lower the lifespan of the SSD.
The Intel X25-M (either G3 or G2) would be sufficient for your purposes.
In general, we do strongly recommend you put a UPS on your system, to
avoid cache corruption in case of power outages.
2) And later, when Solaris gets TRIM support, should I reformat or is there no
need to reformat? I mean, maybe I must format and reinstall to get TRIM all
over the disk. Or will TRIM immediately start to do it's magic?
If/when TRIM is supported by ZFS, I would expect this to transparent to
you, the end-user. You'd have to upgrade the OS to the proper new
patchlevel, and *possibly* run a 'zpool upgrade' to update the various
pools to the latest version, but I suspect the latter will be completely
unnecessary. TRIM support would come in ZFS's guts, not in the pool
format. Worst case is that you'd have to enable TRIM at the device
layer, which would probably entail either editing a config file and
rebooting, or just running some command to enable the feature. I can't
imagine it would require any reformating or reinstalling.
--
Erik Trimble
Java System Support
Mailstop: usca22-123
Phone: x17195
Santa Clara, CA
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