On Thu, Sep 4, 2014 at 2:26 PM, Сергей <[email protected]> wrote: > You need to run Fstrim if you mounted your partition WITHOUT "discard" > option and did lots of changes. For example, if you installed your > system without "discard", do fstrim and then add "discard" to > /etc/fstab. >
Just a note that depending on the SSD model, discard can have a substantial performance penalty with negligible benefit compared to just sticking fstrim in your crontab. In theory the ssd should just handle discard by making a note of what is trimmed and utlizing this information when needed. In practice many ssds handle a trim by dropping whatever they're doing and don't a copy/delete cycle if only part of a block is trimmed, which defeats the whole point of trimming in the first place. FStrim has the advantage of being more asynchronous and possibly being able to consolidate trims over a longer time-period, which could improve performance if the ssd isn't smart about it. Is there a really good place to go for SSD reviews/etc that actually takes this sort of thing into account? After getting an SSD it became apparently that they vary widely in terms of quality. Heck, I can't even tell you what the erase cycle count is from the SMART info, while other models seems to provide all kinds of useful info. -- Rich
