On Tue, May 8, 2012 at 3:16 AM, Shaohua Li <shli@xxxxxxxxxx> wrote: >> > Writing the parity disk is worse. Discard is to improve the garbage >> > collection >> > of SSD firmware, so improve later write performance. While write is bad for >> > SSD, because SSD can be wear leveling out with extra write and also write >> > increases garbage collection overhead. So the result of small >> > discard is data >> > disk garbage collection is improved but parity disk gets worse and >> > parity disk >> > gets fast to end of its life, which doesn't make sense. This is even >> > worse when >> > the parity is distributed. >> Neil, >> Any comments about the patches? > ping! > So, are we still in the position of needing to degrade individual stripes to support trim? Is there any benefit to making this a temporary condition? I.e. trim large ranges, including the parity disk, and then once all the trim sequences have coalesced resync the stripes that remain only partially trimmed? -- 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
