* TRIM support in drivers and dm/md? @ 2010-11-04 13:19 Jeff Layton 2010-11-04 13:40 ` Matthew Wilcox 0 siblings, 1 reply; 8+ messages in thread From: Jeff Layton @ 2010-11-04 13:19 UTC (permalink / raw) To: linux-fsdevel Good morning, Do many of the SATA controllers support TRIM? (i.e. pass the TRIM command to the SSD). Does anyone know anything about dm/md supporting TRIM? (I'm thinking LVM and software RAID tools). Thanks! Jeff ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: TRIM support in drivers and dm/md? 2010-11-04 13:19 TRIM support in drivers and dm/md? Jeff Layton @ 2010-11-04 13:40 ` Matthew Wilcox 2010-11-04 14:46 ` Jeff Layton 0 siblings, 1 reply; 8+ messages in thread From: Matthew Wilcox @ 2010-11-04 13:40 UTC (permalink / raw) To: Jeff Layton; +Cc: linux-fsdevel On Thu, Nov 04, 2010 at 09:19:43AM -0400, Jeff Layton wrote: > Do many of the SATA controllers support TRIM? (i.e. pass > the TRIM command to the SSD). Does anyone know > anything about dm/md supporting TRIM? (I'm thinking LVM > and software RAID tools). As far as I know, there's nothing to be done in any SATA controller driver to support TRIM. It's just up to the drive whether it understands the command. Not sure what the sate of play is with MD/DM and TRIM. It's a bit tricky because some SATA drives will return different garbage from TRIMmed sectors each time they're read. That can hamper a RAID-5/6 rebuild "somewhat". -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: TRIM support in drivers and dm/md? 2010-11-04 13:40 ` Matthew Wilcox @ 2010-11-04 14:46 ` Jeff Layton 2010-11-04 16:45 ` Jeff Garzik 0 siblings, 1 reply; 8+ messages in thread From: Jeff Layton @ 2010-11-04 14:46 UTC (permalink / raw) To: Matthew Wilcox; +Cc: linux-fsdevel On 11/04/2010 09:40 AM, Matthew Wilcox wrote: > On Thu, Nov 04, 2010 at 09:19:43AM -0400, Jeff Layton wrote: >> Do many of the SATA controllers support TRIM? (i.e. pass >> the TRIM command to the SSD). Does anyone know >> anything about dm/md supporting TRIM? (I'm thinking LVM >> and software RAID tools). > As far as I know, there's nothing to be done in any SATA controller > driver to support TRIM. It's just up to the drive whether it understands > the command. That's the rub. I've heard that many drivers don't understand the command. So I'm curious what drivers do and any experience anyone might have. Thanks! ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: TRIM support in drivers and dm/md? 2010-11-04 14:46 ` Jeff Layton @ 2010-11-04 16:45 ` Jeff Garzik 2010-11-04 17:56 ` Jeff Layton 0 siblings, 1 reply; 8+ messages in thread From: Jeff Garzik @ 2010-11-04 16:45 UTC (permalink / raw) To: Jeff Layton; +Cc: Matthew Wilcox, linux-fsdevel On 11/04/2010 10:46 AM, Jeff Layton wrote: > On 11/04/2010 09:40 AM, Matthew Wilcox wrote: >> On Thu, Nov 04, 2010 at 09:19:43AM -0400, Jeff Layton wrote: >>> Do many of the SATA controllers support TRIM? (i.e. pass >>> the TRIM command to the SSD). Does anyone know >>> anything about dm/md supporting TRIM? (I'm thinking LVM >>> and software RAID tools). >> As far as I know, there's nothing to be done in any SATA controller >> driver to support TRIM. It's just up to the drive whether it understands >> the command. > That's the rub. I've heard that many drivers don't understand > the command. So I'm curious what drivers do and any experience > anyone might have. Note the distinction between "drive" and "driver"... I agree with what Matthew says. Jeff ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: TRIM support in drivers and dm/md? 2010-11-04 16:45 ` Jeff Garzik @ 2010-11-04 17:56 ` Jeff Layton 2010-11-04 20:23 ` Jeff Garzik 0 siblings, 1 reply; 8+ messages in thread From: Jeff Layton @ 2010-11-04 17:56 UTC (permalink / raw) To: Jeff Garzik; +Cc: Matthew Wilcox, linux-fsdevel >>>> Do many of the SATA controllers support TRIM? (i.e. pass >>>> the TRIM command to the SSD). Does anyone know >>>> anything about dm/md supporting TRIM? (I'm thinking LVM >>>> and software RAID tools). > >>> As far as I know, there's nothing to be done in any SATA controller >>> driver to support TRIM. It's just up to the drive whether it >>> understands >>> the command. > >> That's the rub. I've heard that many drivers don't understand >> the command. So I'm curious what drivers do and any experience >> anyone might have. > > Note the distinction between "drive" and "driver"... I agree with > what Matthew says. > Oops - sorry I missed "drive" vs. "driver". I've heard from other places that drivers need to pass along the TRIM command to the drives but that many drivers don't do this. I assume that the best way to determine if this is accurate is to test the controller drivers or ping the maintainers. Thanks! ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: TRIM support in drivers and dm/md? 2010-11-04 17:56 ` Jeff Layton @ 2010-11-04 20:23 ` Jeff Garzik 2010-11-05 2:44 ` Mark Lord 0 siblings, 1 reply; 8+ messages in thread From: Jeff Garzik @ 2010-11-04 20:23 UTC (permalink / raw) To: Jeff Layton; +Cc: Matthew Wilcox, linux-fsdevel, Linux IDE mailing list On 11/04/2010 01:56 PM, Jeff Layton wrote: > >>>>> Do many of the SATA controllers support TRIM? (i.e. pass >>>>> the TRIM command to the SSD). Does anyone know >>>>> anything about dm/md supporting TRIM? (I'm thinking LVM >>>>> and software RAID tools). >> >>>> As far as I know, there's nothing to be done in any SATA controller >>>> driver to support TRIM. It's just up to the drive whether it >>>> understands >>>> the command. >> >>> That's the rub. I've heard that many drivers don't understand >>> the command. So I'm curious what drivers do and any experience >>> anyone might have. >> >> Note the distinction between "drive" and "driver"... I agree with what >> Matthew says. >> > > Oops - sorry I missed "drive" vs. "driver". > > I've heard from other places that drivers need to pass along > the TRIM command to the drives but that many drivers don't > do this. I assume that the best way to determine if this is > accurate is to test the controller drivers or ping the maintainers. I'd object to the words "many" and "drivers" :) The general rule for all kernel SATA drivers is to support all ATA commands, including future, unknown commands not invented yet. That's because kernel SATA drivers deal primarily with the sending/receiving from hardware an opaque data bundle -- the ATA taskfile -- rather than create a software system that requires new code in each driver, for each new ATA command. That's the ideal and, if you obtained a SATA controller in the past 5 years or so, your controller (ahci, sata_sil24, others) supports TRIM just fine because it is a generic ATA taskfile transport and nothing more. Some now-uncommon controllers have problems with new ATA commands, either due to (a) they are complex, firmware-driven RAID-esque beasts, or (b) they have an internal command table. And I imagine some early SATA<->PATA bridge chips probably get confused as well. But those are the minority, and getting less frequent by the day. Note in all of the above I say "controller" rather than "driver". I know of no _driver_ that prevents TRIM, where the underlying controller hardware supports it. For the controllers that don't support TRIM, the error behavior should be something predictable and consistent like a command abort. Jeff ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: TRIM support in drivers and dm/md? 2010-11-04 20:23 ` Jeff Garzik @ 2010-11-05 2:44 ` Mark Lord 2010-11-05 2:56 ` Jeff Garzik 0 siblings, 1 reply; 8+ messages in thread From: Mark Lord @ 2010-11-05 2:44 UTC (permalink / raw) To: Jeff Garzik Cc: Jeff Layton, Matthew Wilcox, linux-fsdevel, Linux IDE mailing list sata_sil didn't support trim the last time I checked (the hardware can do it though). sata_sil24 does, though, along with ahci, sata_mv, etc.. Cheers ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: TRIM support in drivers and dm/md? 2010-11-05 2:44 ` Mark Lord @ 2010-11-05 2:56 ` Jeff Garzik 0 siblings, 0 replies; 8+ messages in thread From: Jeff Garzik @ 2010-11-05 2:56 UTC (permalink / raw) To: Mark Lord Cc: Jeff Layton, Matthew Wilcox, linux-fsdevel, Linux IDE mailing list On 11/04/2010 10:44 PM, Mark Lord wrote: > sata_sil didn't support trim the last time I checked (the hardware can > do it though). > sata_sil24 does, though, along with ahci, sata_mv, etc.. The recent sata_mv bugfix should be noted of course... ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2010-11-05 2:56 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-11-04 13:19 TRIM support in drivers and dm/md? Jeff Layton 2010-11-04 13:40 ` Matthew Wilcox 2010-11-04 14:46 ` Jeff Layton 2010-11-04 16:45 ` Jeff Garzik 2010-11-04 17:56 ` Jeff Layton 2010-11-04 20:23 ` Jeff Garzik 2010-11-05 2:44 ` Mark Lord 2010-11-05 2:56 ` Jeff Garzik
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