On 22 February 2011 01:46, Roberto Spadim <roberto@xxxxxxxxxxxxx> wrote: > if it make sense on ssd, harddisk make sense too, it's a block device > like ssd, the diference of ssd/harddisk? access time, > bytes(bits)/block, life time > bad block exist in ssd and harddisk, ssd can realloc online, some harddisks too > >> no, because the host may immediately write to a trim'd sector > yes, filesystem know where exists a unused sector > if device (harddisk/ssd) know and have a reallocation algorithm, it > can realloc without telling filesystem to do it (that's why TRIM is > interesting) > since today ssd use NAND (not NOR) the block size isn't 1 bit like a > harddisk head. trim for harddisk only make sense for badblock > reallocation > -------------------------- > getting back to the first question, can MD support trim? yes/no/not > now/some levels and layouts only? > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial This explains a bit why trim is good for SSDs and has nothing to do with harddrives at all, since they use spinning platters and not chips. http://www.anandtech.com/show/2738/10 // Mathias -- 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
