Re: how to fsck automatically at boot
On 5/22/24 08:08, Kirill A. Korinsky wrote: On Wed, 22 May 2024 12:53:11 +0100, Nick Holland wrote: For reasons of multi-hour fsck's on a few systems, I'm looking at remounting the problem file systems as "rw" when writing is actually needed and "ro" after the writing is complete (IN THIS APPLICATION, this is known) to reduce my "at risk of power outage" window a lot, but I suspect this will fall deeply within the category of "when I break things, I get to keep all the pieces". :) Do you need atime on that FS? Disable it dramatically reduces chances of manual interraction with fsck. If you move forward and add sync which slow down write but allows to get almost zero porbability of fsck interraction. Already done. :) This is a backup system I have -- lots of symlinks, lots of files. Cool thing is, the fsck is painful, but almost never have to help the fsck along, at least once softdep was removed and they quit crashing in the middle of backups. (softdep removal really hurt these systems -- some tasks went from an hour or so to many hours...but it doesn't impact my life one bit. On the other hand, obviously I was tickling some of those softdep bugs I had heard hit some people). And in other news: couple days ago, I said I rarely need manual intervention on the systems I just yank the cords from. Well, this morning, a system I manage remotely apparently had a couple power events, and one system needed help with the fsck. That's what happens when one boasts. :D Nick.
Re: how to fsck automatically at boot
On 2024-05-22, Kirill A Korinsky wrote: > On Wed, 22 May 2024 12:53:11 +0100, > Nick Holland wrote: >> > Do you need atime on that FS? Disable it dramatically reduces chances of > manual interraction with fsck. btw: you probably _do_ want atime on /tmp (see /etc/daily). But that's a fairly good candidate for MFS anyway.
Re: how to fsck automatically at boot
On Wed, 22 May 2024 12:53:11 +0100, Nick Holland wrote: > > For reasons of multi-hour fsck's on a few systems, I'm looking at > remounting the problem file systems as "rw" when writing is actually > needed and "ro" after the writing is complete (IN THIS APPLICATION, this > is known) to reduce my "at risk of power outage" window a lot, but I > suspect this will fall deeply within the category of "when I break > things, I get to keep all the pieces". :) > Do you need atime on that FS? Disable it dramatically reduces chances of manual interraction with fsck. If you move forward and add sync which slow down write but allows to get almost zero porbability of fsck interraction. -- wbr, Kirill
Re: how to fsck automatically at boot
On 5/21/24 08:28, Stuart Henderson wrote: On 2024-05-21, Nick Holland wrote: ... When I remove that disk the boot sequence stops and asks for a fsck I would like that this disk is mounted when it's present, but when it's not installed I don't want the boot sequence to stop Make it also "noauto" in fstab and mount it in rc.local. Last I tried this, it didn't do what I wanted -- "noauto" still expects to have the disk there and will fsck it on boot. Failure to be able to do this stops the boot. It's been a while since I last tried this, so perhaps something has changed (including my recollection?) See fstab(5) about fs_passno. ah, so "0" or blank. cool. learned something. That will simplify a few things! And this might be a solution for the OP's problem: make /usr and /usr/* "ro" during normal operation reorder_kernel is run in the background from /etc/rc; for RO /usr you need to wait for that to finish. And I forgot that. d'oh. So yes, file my tidbit under "REALLY BAD ADVICE" and ignore it. For reasons of multi-hour fsck's on a few systems, I'm looking at remounting the problem file systems as "rw" when writing is actually needed and "ro" after the writing is complete (IN THIS APPLICATION, this is known) to reduce my "at risk of power outage" window a lot, but I suspect this will fall deeply within the category of "when I break things, I get to keep all the pieces". :) Nick.
Re: how to fsck automatically at boot
Hello Nick, Stuart, Kirill, Jan, Thank you for all your answers. Le mardi 21 mai 2024 à 14:31:13 UTC+2, Stuart Henderson a écrit : On 2024-05-21, Nick Holland wrote: > On 5/20/24 09:37, Jan Stary wrote: >> On May 20 13:22:26, mikyde...@yahoo.fr wrote: >>> Hello, >>> >>> I have two use cases and problems with fsck. >>> >>> 1) When my openbsd boots after an outage, the system asks me to fsck /, >>> /usr, /var or /home manually. >>> So I do >>> fsck /dev/sd0a >>> And then I'm asked questions and I usually answer F >>> >>> So my question is that I want this process to be done automatically at boot >>> time for each partition that has a problem. >> >> The /etc/rc boot script calls fsck -p; >> if that fails, it means fsck -p was unable to fix a major problem. >> It is the point that it requires an admin's intervention. >> >> You would have to change the fsck call to fsck -y; >> but don't do that. AIUI the rationale for not using -y by default is that fsck may do further damage to a badly damaged disk. But in practice many people wouldn't do anything other than hit 'y' lots or 'F' when fsck complains, in which case patching /etc/rc to run -y by default isn't going to be any worse... And there are certainly some classes of system where you don't really care about losing data (i.e. you can recreate from config management or backups) but you do want to maximise the chances of being able to connect in remotely, and in that case -y can definitely help. > I'd look at why your file systems are always needing these manual > interventions after a hard shutdown. I routinely power down my > personal systems with yanking the power cord if it would take me > longer "properly" connect a console and properly shut down. That really depends on what the system is doing. >>> When I remove that disk the boot sequence stops and asks for a fsck >>> I would like that this disk is mounted when it's present, but when it's not >>> installed I don't want the boot sequence to stop >> >> Make it also "noauto" in fstab and mount it in rc.local. > > Last I tried this, it didn't do what I wanted -- "noauto" still expects > to have the disk there and will fsck it on boot. Failure to be able to > do this stops the boot. It's been a while since I last tried this, so > perhaps something has changed (including my recollection?) See fstab(5) about fs_passno. > And this might be a solution for the OP's problem: > make /usr and /usr/* "ro" during normal operation reorder_kernel is run in the background from /etc/rc; for RO /usr you need to wait for that to finish. -- Please keep replies on the mailing list.
Re: how to fsck automatically at boot
On 2024-05-21, Nick Holland wrote: > On 5/20/24 09:37, Jan Stary wrote: >> On May 20 13:22:26, mikyde...@yahoo.fr wrote: >>> Hello, >>> >>> I have two use cases and problems with fsck. >>> >>> 1) When my openbsd boots after an outage, the system asks me to fsck /, >>> /usr, /var or /home manually. >>> So I do >>> fsck /dev/sd0a >>> And then I'm asked questions and I usually answer F >>> >>> So my question is that I want this process to be done automatically at boot >>> time for each partition that has a problem. >> >> The /etc/rc boot script calls fsck -p; >> if that fails, it means fsck -p was unable to fix a major problem. >> It is the point that it requires an admin's intervention. >> >> You would have to change the fsck call to fsck -y; >> but don't do that. AIUI the rationale for not using -y by default is that fsck may do further damage to a badly damaged disk. But in practice many people wouldn't do anything other than hit 'y' lots or 'F' when fsck complains, in which case patching /etc/rc to run -y by default isn't going to be any worse... And there are certainly some classes of system where you don't really care about losing data (i.e. you can recreate from config management or backups) but you do want to maximise the chances of being able to connect in remotely, and in that case -y can definitely help. > I'd look at why your file systems are always needing these manual > interventions after a hard shutdown. I routinely power down my > personal systems with yanking the power cord if it would take me > longer "properly" connect a console and properly shut down. That really depends on what the system is doing. >>> When I remove that disk the boot sequence stops and asks for a fsck >>> I would like that this disk is mounted when it's present, but when it's not >>> installed I don't want the boot sequence to stop >> >> Make it also "noauto" in fstab and mount it in rc.local. > > Last I tried this, it didn't do what I wanted -- "noauto" still expects > to have the disk there and will fsck it on boot. Failure to be able to > do this stops the boot. It's been a while since I last tried this, so > perhaps something has changed (including my recollection?) See fstab(5) about fs_passno. > And this might be a solution for the OP's problem: > make /usr and /usr/* "ro" during normal operation reorder_kernel is run in the background from /etc/rc; for RO /usr you need to wait for that to finish. -- Please keep replies on the mailing list.
Re: how to fsck automatically at boot
On 5/20/24 09:37, Jan Stary wrote: On May 20 13:22:26, mikyde...@yahoo.fr wrote: Hello, I have two use cases and problems with fsck. 1) When my openbsd boots after an outage, the system asks me to fsck /, /usr, /var or /home manually. So I do fsck /dev/sd0a And then I'm asked questions and I usually answer F So my question is that I want this process to be done automatically at boot time for each partition that has a problem. The /etc/rc boot script calls fsck -p; if that fails, it means fsck -p was unable to fix a major problem. It is the point that it requires an admin's intervention. You would have to change the fsck call to fsck -y; but don't do that. I'd look at why your file systems are always needing these manual interventions after a hard shutdown. I routinely power down my personal systems with yanking the power cord if it would take me longer "properly" connect a console and properly shut down. yeah, I get fscks, but I rarely get a manual intervention required. It does happen...but rarely. (Also, don't let a server have power outages, obviously.) This is because I use a small server without screen and keyboard. So what? That is no excuse to leave broken filesystems unattended. 2) I have another disk in my small server, and I mount one partition of it with in fstab aa929243b0f5.a /var/mylogs ffs rw,nodev,nosuid 1 2 When I remove that disk the boot sequence stops and asks for a fsck I would like that this disk is mounted when it's present, but when it's not installed I don't want the boot sequence to stop Make it also "noauto" in fstab and mount it in rc.local. Last I tried this, it didn't do what I wanted -- "noauto" still expects to have the disk there and will fsck it on boot. Failure to be able to do this stops the boot. It's been a while since I last tried this, so perhaps something has changed (including my recollection?) I have some backup servers with big file systems that can take hours to fsck. I pulled the mount lines out of /etc/fstab and put them in a separate script that is invoked at boot from /etc/rc.local And this might be a solution for the OP's problem: make /usr and /usr/* "ro" during normal operation, and move all the "lots of volatile data" stuff over to partitions that are mounted post boot by a separate script. Maybe make /tmp an MFS if that's an option. That will minimize the fsck problems, and allow the system to come up for either manual, remote fixing or even fsck -y in the mountall script. Don't forget you ro'd the /usr partitions, otherwise your upgrades will be unpleasant. :) Nick.
Re: how to fsck automatically at boot
On Mon, 20 May 2024 14:22:26 +0100, Mik J wrote: > > aa929243b0f5.a /var/mylogs ffs rw,nodev,nosuid 1 2 You may add noatime which should decrease probability of issues when an outage had happened. Also, you may consider to use sync option which should future decrease probability of issues on an outage. -- wbr, Kirill
Re: how to fsck automatically at boot
On May 20 13:22:26, mikyde...@yahoo.fr wrote: > Hello, > > I have two use cases and problems with fsck. > > 1) When my openbsd boots after an outage, the system asks me to fsck /, /usr, > /var or /home manually. > So I do > fsck /dev/sd0a > And then I'm asked questions and I usually answer F > > So my question is that I want this process to be done automatically at boot > time for each partition that has a problem. The /etc/rc boot script calls fsck -p; if that fails, it means fsck -p was unable to fix a major problem. It is the point that it requires an admin's intervention. You would have to change the fsck call to fsck -y; but don't do that. (Also, don't let a server have power outages, obviously.) > This is because I use a small server without screen and keyboard. So what? That is no excuse to leave broken filesystems unattended. > 2) I have another disk in my small server, and I mount one partition of it > with in fstab > aa929243b0f5.a /var/mylogs ffs rw,nodev,nosuid 1 2 > When I remove that disk the boot sequence stops and asks for a fsck > I would like that this disk is mounted when it's present, but when it's not > installed I don't want the boot sequence to stop Make it also "noauto" in fstab and mount it in rc.local. (Also, don't remove disks from servers, obviously.)
