> I have not worked with SSDs, though I've read all the good information that's > trickling to us from Denmark. One thing that I've been wondering all along is > - what about writes? That is, what about writes "wearing out" the SSD? How > quickly does that happen and when it does happen, what are the symptoms? For > example, does it happen after N write operations? Do writes start failing and > one starts getting IOExceptions in case of Lucene and Solr?
With modern SSDs you get something in the region of 500,000 to 1,000,000 write cycles per memory cell. Additionally they all use wear leveling, i.e. the writes are spread over the whole disk -- you can write to a file system block many times more. One of the manufacturers of high-end SSDs [1] claims that at a sustained write rate of 50GB per day their drives will last more than 140 years, i.e. it's much more likely that something else will fail before ;) When the write cycles are "exhausted" much the same thing as with a bad conventional disk happens -- you'll see lots of write errors. If the wear leveling is perfect (i.e. all memory locations have exactly the same number of writes) it's even possible that the whole disk will fail at once. Lars [1] http://www.mtron.net
