Re: btrfs-balance causes system-freeze on full disk
Am 2015-10-27 um 18:09 schrieb Hugo Mills: > On Tue, Oct 27, 2015 at 05:05:55PM +0100, Jakob Schürz wrote: >> Found a new habit... >> >> I have a lot Snapshots on my drive. (Take every 10 Min a new one, every >> houry one, every day one, every system-update, every plugin after >> external HD...) >> >> If there are to much snapshots (didn't find out the count how much >> exactly) balancing fails with a system-freeze. >> if i delete some of my snapshots, balancing is working... > >The whole machine comes to a halt, or just the balancing? The whole machine. Even magic-sysreq-keys are not reacting... I have to reboot my machine using the power-button... > If you > have lots of snapshots, balance can take *insane* amounts of time -- > my big storage array, for example, takes about 60 seconds to balance a > data block group, and something like 4+ hours to balance some of the > metadata block groups. While it's "stuck" like that, it is actually > making progress, but it doesn't look like it. I know, balancint takes a huge amount of time. So my command is: /bin/btrfs balance start -dusage=55 -v When balancing is running, the machine reactes a little slower than normal... but in my case, the machine is freezing. completly and totally... :( greez jakob signature.asc Description: OpenPGP digital signature
Re: btrfs-balance causes system-freeze on full disk
On Tue, Oct 27, 2015 at 05:05:55PM +0100, Jakob Schürz wrote: > Found a new habit... > > I have a lot Snapshots on my drive. (Take every 10 Min a new one, every > houry one, every day one, every system-update, every plugin after > external HD...) > > If there are to much snapshots (didn't find out the count how much > exactly) balancing fails with a system-freeze. > if i delete some of my snapshots, balancing is working... The whole machine comes to a halt, or just the balancing? If you have lots of snapshots, balance can take *insane* amounts of time -- my big storage array, for example, takes about 60 seconds to balance a data block group, and something like 4+ hours to balance some of the metadata block groups. While it's "stuck" like that, it is actually making progress, but it doesn't look like it. Hugo. > Maybe this is a hint for bugfixing!! > > Do you think? > > greez > > Jakob > > Am 2015-10-21 um 22:51 schrieb Kyle Manna: > > I had a number of similar btrfs balance crashes in the past few days, > > but the disk wasn't full. You should try tailing the system logs from > > a remote machine when it happens. You'll likely see some bug info > > before the system dies and becomes unusable. > > > > The issue I encountered is described @ > > https://bugzilla.kernel.org/show_bug.cgi?id=105681 > > ᐧ > > > > On Wed, Oct 21, 2015 at 12:38 PM, Jakob Schürz > > wrote: > >> Hi there! > >> > >> Is it possible, what i've recognized now. My system (debian) runs on > >> btrfs, and i have a lot of snapshots on my hard-disk. > >> Since some days my system freezes totally. I recognized, it always > >> happens during btrfs-balance. > >> > >> So i deleted some of the old snapshots and tried another balance-run. > >> Nothing happened... No system-freeze. > >> > >> System-freeze means: No Keyboard-action. The Mouse is frozen, the screen > >> is frozen, no magic-sysreq, no ssh-login. > >> > >> Can btrfs cause such a freeze?? > >> > >> greez > >> > >> jakob -- Hugo Mills | Darkling's First Law of Filesystems: hugo@... carfax.org.uk | The user hates their data http://carfax.org.uk/ | PGP: E2AB1DE4 | signature.asc Description: Digital signature
Re: btrfs-balance causes system-freeze on full disk
On Tue, Oct 27, 2015 at 4:05 PM, Jakob Schürz wrote: > Found a new habit... > > I have a lot Snapshots on my drive. (Take every 10 Min a new one, every > houry one, every day one, every system-update, every plugin after > external HD...) > > If there are to much snapshots (didn't find out the count how much > exactly) balancing fails with a system-freeze. > if i delete some of my snapshots, balancing is working... > > Maybe this is a hint for bugfixing!! A patch set to fix this issue was already sent yesterday and tested over the weekend by Stéphane: http://thread.gmane.org/gmane.comp.file-systems.btrfs/49630 cheers > > Do you think? > > greez > > Jakob > > Am 2015-10-21 um 22:51 schrieb Kyle Manna: >> I had a number of similar btrfs balance crashes in the past few days, >> but the disk wasn't full. You should try tailing the system logs from >> a remote machine when it happens. You'll likely see some bug info >> before the system dies and becomes unusable. >> >> The issue I encountered is described @ >> https://bugzilla.kernel.org/show_bug.cgi?id=105681 >> ᐧ >> >> On Wed, Oct 21, 2015 at 12:38 PM, Jakob Schürz >> wrote: >>> Hi there! >>> >>> Is it possible, what i've recognized now. My system (debian) runs on >>> btrfs, and i have a lot of snapshots on my hard-disk. >>> Since some days my system freezes totally. I recognized, it always >>> happens during btrfs-balance. >>> >>> So i deleted some of the old snapshots and tried another balance-run. >>> Nothing happened... No system-freeze. >>> >>> System-freeze means: No Keyboard-action. The Mouse is frozen, the screen >>> is frozen, no magic-sysreq, no ssh-login. >>> >>> Can btrfs cause such a freeze?? >>> >>> greez >>> >>> jakob >>> -- >>> http://xundeenergie.at >>> http://verkehrsloesungen.wordpress.com/ >>> http://cogitationum.wordpress.com/ >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >>> the body of a message to majord...@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > > -- > http://xundeenergie.at > http://verkehrsloesungen.wordpress.com/ > http://cogitationum.wordpress.com/ > -- Filipe David Manana, "Reasonable men adapt themselves to the world. Unreasonable men adapt the world to themselves. That's why all progress depends on unreasonable men." -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: btrfs-balance causes system-freeze on full disk
Found a new habit... I have a lot Snapshots on my drive. (Take every 10 Min a new one, every houry one, every day one, every system-update, every plugin after external HD...) If there are to much snapshots (didn't find out the count how much exactly) balancing fails with a system-freeze. if i delete some of my snapshots, balancing is working... Maybe this is a hint for bugfixing!! Do you think? greez Jakob Am 2015-10-21 um 22:51 schrieb Kyle Manna: > I had a number of similar btrfs balance crashes in the past few days, > but the disk wasn't full. You should try tailing the system logs from > a remote machine when it happens. You'll likely see some bug info > before the system dies and becomes unusable. > > The issue I encountered is described @ > https://bugzilla.kernel.org/show_bug.cgi?id=105681 > ᐧ > > On Wed, Oct 21, 2015 at 12:38 PM, Jakob Schürz > wrote: >> Hi there! >> >> Is it possible, what i've recognized now. My system (debian) runs on >> btrfs, and i have a lot of snapshots on my hard-disk. >> Since some days my system freezes totally. I recognized, it always >> happens during btrfs-balance. >> >> So i deleted some of the old snapshots and tried another balance-run. >> Nothing happened... No system-freeze. >> >> System-freeze means: No Keyboard-action. The Mouse is frozen, the screen >> is frozen, no magic-sysreq, no ssh-login. >> >> Can btrfs cause such a freeze?? >> >> greez >> >> jakob >> -- >> http://xundeenergie.at >> http://verkehrsloesungen.wordpress.com/ >> http://cogitationum.wordpress.com/ >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- http://xundeenergie.at http://verkehrsloesungen.wordpress.com/ http://cogitationum.wordpress.com/ signature.asc Description: OpenPGP digital signature
Re: btrfs-balance causes system-freeze on full disk
Kyle Manna posted on Wed, 21 Oct 2015 13:51:22 -0700 as excerpted: > The issue I encountered is described @ > https://bugzilla.kernel.org/show_bug.cgi?id=105681 FWIW... I won't try to deal with the issue reported there, but I can help clear something up that's mentioned on the bug[1]. The question (comment 5 and 6) refers to btrfs device usage output, for a three-device btrfs raid1, both data/metadata. The question was why only two of the three devices listed a system chunk. Btrfs raid1, unlike say mdraid1, is strictly pair-mirror, exactly two copies of the chunk, one each on two different devices. More devices adds to the space available, not to the number of redundant copies. As it happens, the two devices that got a copy of the system chunk were sdb and sdd, sdc didn't get a copy, as there are only two copies to distribute, no matter the number of devices in the raid1. And as it happens, I've been personally interested in and thus following the roadmapped btrfs N-way-mirroring, the feature that would put a copy on all three devices, this being my most hotly anticipated btrfs feature since 3-way-mirroring is about the perfect balance between cost and reliability due to device redundancy, for me. For quite some time now, a new N-way-mirroring feature has been on the roadmap, to be worked on after raid56 mode, as the planned implementation was to use some of the same code. Raid56 mode is complete now, tho it took far longer than initially expected, so hopefully n-way-mirroring is already in development. However, given the time raid56 took, 2-3 years of development, it's likely to be some time before n-way-mirroring actually appears. And again, if it follows the pattern of other btrfs features, it'll take a couple kernel cycles after initial release to stabilize to actual usability, and a full year (five cycles) to stabilize to approximately the same maturity/stability as the rest of btrfs in general. For raid56, nominally code-complete in 3.19, the last critical bug was in the early 4.1 code, fixed by 4.1 release. But my recommendation has been to wait another couple cycles just to be sure nothing else "interesting" comes up, basically a full year, five kernel cycles, after nominal code- complete release. That would be 4.4... Back to N-way-mirroring, assuming the work doesn't get delayed by something else, I'd EWAG (educated WAG) an 18 month to 2 year development time to nominally complete. That would put initial release around 4.7-4.9, actual usability at 4.9-4.11, and year-on stability at 4.12-4.14. So altho we're nearing a year since raid56 nominal-completion, I don't expect N-way-mirroring code release for another year or so yet, don't expect it to be really usable for another five months (two kernel cycles) after that, and even then, wouldn't expect it to be as stable as the rest of btrfs for another further three kernels or so, thus putting actual reasonable stability (compared to the already stable 2-way raid1 code) two years out... So it's coming, and at least now it's close enough there's /some/ estimate of when it might be available, but it's going to be some time yet before I'd expect even nominal code-completion release, and some time after that before it reaches the stability benefit that I'm actually hotly anticipating the feature for. Very roughly two years from now, tho I'd not be surprised at all to see that slide another six months to a year, and that's assuming nothing else shoves it out of the way, priority- wise. --- [1] I do have a kernel-bugs login but didn't want to bother logging in just to add the comment there, when I had just clicked a link here to get there, and could simply reply here instead. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: btrfs-balance causes system-freeze on full disk
Thx! It seems to be the same bug. Am 2015-10-21 um 22:51 schrieb Kyle Manna: > I had a number of similar btrfs balance crashes in the past few days, > but the disk wasn't full. You should try tailing the system logs from > a remote machine when it happens. You'll likely see some bug info > before the system dies and becomes unusable. > > The issue I encountered is described @ > https://bugzilla.kernel.org/show_bug.cgi?id=105681 > ᐧ > > On Wed, Oct 21, 2015 at 12:38 PM, Jakob Schürz > wrote: >> Hi there! >> >> Is it possible, what i've recognized now. My system (debian) runs on >> btrfs, and i have a lot of snapshots on my hard-disk. >> Since some days my system freezes totally. I recognized, it always >> happens during btrfs-balance. >> >> So i deleted some of the old snapshots and tried another balance-run. >> Nothing happened... No system-freeze. >> >> System-freeze means: No Keyboard-action. The Mouse is frozen, the screen >> is frozen, no magic-sysreq, no ssh-login. >> >> Can btrfs cause such a freeze?? >> >> greez >> >> jakob >> -- >> http://xundeenergie.at >> http://verkehrsloesungen.wordpress.com/ >> http://cogitationum.wordpress.com/ >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- http://xundeenergie.at http://verkehrsloesungen.wordpress.com/ http://cogitationum.wordpress.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: btrfs-balance causes system-freeze on full disk
I had a number of similar btrfs balance crashes in the past few days, but the disk wasn't full. You should try tailing the system logs from a remote machine when it happens. You'll likely see some bug info before the system dies and becomes unusable. The issue I encountered is described @ https://bugzilla.kernel.org/show_bug.cgi?id=105681 ᐧ On Wed, Oct 21, 2015 at 12:38 PM, Jakob Schürz wrote: > Hi there! > > Is it possible, what i've recognized now. My system (debian) runs on > btrfs, and i have a lot of snapshots on my hard-disk. > Since some days my system freezes totally. I recognized, it always > happens during btrfs-balance. > > So i deleted some of the old snapshots and tried another balance-run. > Nothing happened... No system-freeze. > > System-freeze means: No Keyboard-action. The Mouse is frozen, the screen > is frozen, no magic-sysreq, no ssh-login. > > Can btrfs cause such a freeze?? > > greez > > jakob > -- > http://xundeenergie.at > http://verkehrsloesungen.wordpress.com/ > http://cogitationum.wordpress.com/ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
btrfs-balance causes system-freeze on full disk
Hi there! Is it possible, what i've recognized now. My system (debian) runs on btrfs, and i have a lot of snapshots on my hard-disk. Since some days my system freezes totally. I recognized, it always happens during btrfs-balance. So i deleted some of the old snapshots and tried another balance-run. Nothing happened... No system-freeze. System-freeze means: No Keyboard-action. The Mouse is frozen, the screen is frozen, no magic-sysreq, no ssh-login. Can btrfs cause such a freeze?? greez jakob -- http://xundeenergie.at http://verkehrsloesungen.wordpress.com/ http://cogitationum.wordpress.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html