TRIM is a new feature for many hard disk/ssd it´s more to get a bigger life o disk, allow a dynamic badblock reallocation (filesystem must tell where is empty) 2011/2/21 Phillip Susi <psusi@xxxxxxxxxx>: > On 2/9/2011 10:49 AM, David Brown wrote: >> I've been reading a little more about this. It seems that the days of >> TRIM may well be numbered - the latest generation of high-end SSDs have >> more powerful garbage collection algorithms, together with more spare >> blocks, making TRIM pretty much redundant. This is, of course, the most >> convenient solution for everyone (as long as it doesn't cost too much!). >> >> The point of the TRIM command is to tell the SSD that a particular block >> is no longer being used, so that the SSD can erase it in the background >> - that way when you want to write more data, there are more free blocks >> ready and waiting. But if you've got plenty of spare blocks, it's easy >> to have them erased in advance and you don't need TRIM. > > It is not just about having free blocks ready and waiting. When doing > wear leveling, you might find an erase block that has not been written > to in a long time, so you want to move that data to a more worn block, > and use the less worn block for more frequently written to sectors. If > you know that sectors are unused because they have been TRIMed, then you > don't have to waste time and wear copying the junk there to the new > flash block. > > TRIM is also quite useful for thin provisioned storage, which seems to > be getting popular. > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Roberto Spadim Spadim Technology / SPAEmpresarial -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
