On 21 February 2011 23:41, Mathias BurÃn <mathias.buren@xxxxxxxxx> wrote: > On 21 February 2011 22:52, Roberto Spadim <roberto@xxxxxxxxxxxxx> wrote: >> i donÂt think so, since itÂs ATA command, any ATA compatible can use >> it, it could be used for HD with badblocks and dynamic reallocation >> without problems, the harddisk donÂt need a dedicated space for >> badblock. for md software we must know if devices support or not TRIM. >> >> the next question, md is ATA compatible? no!?, itÂs a linux device, >> not a ATA device. what commands linux devices allow? could md allow >> TRIM? >> >> 2011/2/21 Mathias BurÃn <mathias.buren@xxxxxxxxx>: >>> On 21 February 2011 20:47, Phillip Susi <psusi@xxxxxxxxxx> wrote: >>>> On 2/21/2011 2:39 PM, Roberto Spadim wrote: >>>>> sorry, but i sent email without a information: >>>>> TRIM is a 'ATA Specification' command >>>>> >>>>> http://en.wikipedia.org/wiki/TRIM_command >>>>> >>>>> any disk with ATA command could suport TRIM, hard disk or ssd or >>>>> anyother type of phisical allocation >>>> >>>> Sure, but hard disks have no reason to, which is why they don't and >>>> won't support it. >>>> >>> >>> My point exactly. >>> >>> // M >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at Âhttp://vger.kernel.org/majordomo-info.html >>> >> >> >> >> -- >> Roberto Spadim >> Spadim Technology / SPAEmpresarial >> > > Please don't top post. > http://www.splitbrain.org/blog/2011-02/15-top_posting_like_dont_i_why > > Harddrives already have an allocated area with spare sectors, which > they use whenever they need to. You can find out how many sectors have > been reallocated by the HDD by looking at the SMART data, like so: > > SMART Attributes Data Structure revision number: 16 > Vendor Specific SMART Attributes with Thresholds: > ID# ATTRIBUTE_NAME     ÂFLAG   VALUE WORST THRESH TYPE > UPDATED ÂWHEN_FAILED RAW_VALUE > [...] > Â5 Reallocated_Sector_Ct  0x0033  200  200  140  ÂPre-fail > Always    -    0 > > // M > I forgot to write that the trim command has nothing to do with bad blocks or sectors, it's just a way of "resetting" blocks so that can be written to without having to erase them first. (IIRC) There is no such issue with HDDs, therefore have no benefit at all using the trim command with them. // M -- 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
