Re: Question about forcing fsck at boottime
On Apr 6, 2009, at 11:12, Chris Rees wrote: Can no-one can come up with a reply either quoting a mailing list or giving the circumstances when: a) Background fsck caused data CORRUPTION _and_ b) A foreground fsck would not have done the same ? 2009/4/6 Doug Hardie bc...@lafn.org: Yes. When background FSCK first became standard I let it go that way on my production servers. The first time we had a power issue that resulted in a shutdown of a server it tried to come back up when the power was restored. I have a large number of daemons that rely on configure files and other information that is reasonably frequently updated. Some of those files were in the process of being updated when it shut down. As a result background FSCK did not get around to those files till much after the daemons were up and running (or trying to run). Most of them worked ok at the beginning. However after FSCK resolved the problems, the underlying files changed. The daemons couldn't function at that point. While a simple reboot at that point fixed everything, that caused yet another outage for users. snip So, the answer is NO, it does NOT cause data CORRUPTION. A simple reboot solved it? Really, you're advocating guaranteed extended downtime every time there's a power outage, compared with a slight chance of a slightly longer downtime while every other time it comes almost straight up. Any more replies, please, read the damned question. I doubt that the concept of background FSCK is broken and I suspect that the implementation is good too. _Thank_ you Chris -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Apr 7, 2009, at 02:34, Chris Rees wrote: \ So, the answer is NO, it does NOT cause data CORRUPTION. A simple reboot solved it? Really, you're advocating guaranteed extended downtime every time there's a power outage, compared with a slight chance of a slightly longer downtime while every other time it comes almost straight up. Any more replies, please, read the damned question. You had better define data corruption then. In my book data that is read and gives garbage back rather than the right data is corrupt. It doesn't matter if it gets fixed by a reboot later. Thats only helpful if you happen to notice that it needs a reboot. If all you are interested in is toy systems then this type of problem is of no interest to you. However, for those of us who run production systems where clients have paid for service this is a serious issue. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
2009/4/6 Bruce Cran br...@cran.org.uk: On Sun, 5 Apr 2009 21:40:52 +0100 Chris Rees utis...@googlemail.com wrote: 2009/3/31 Oliver Fromme o...@lurza.secnetix.de: Chris Rees utis...@googlemail.com wrote: 2009/3/31 Wojciech Puchar woj...@wojtek.tensor.gdynia.pl: IMHO this background fsck isn't good idea at all Why? Google background fsck damage. I was bitten by it myself, and I also recommend to turn background fsck off. If your disks are large and you can't afford the fsck time, consider using ZFS, which has a lot of benefits besides not requiring fsck. Best regards Oliver Right... You were bitten by background fsck, what _exactly_ happened? All the 'problems' here associated with bgfsck are referring to FreeBSD 4 etc, or incredibly vague anecdotal evidence. Have you googled for background fsck damage? Nothing (in the first two pages at least) even suggests that background fsck causes damage. http://www.google.co.uk/search?q=background+fsck+corruption You'll find the first few results are about panics during background fsck resulting in an endless cycle of boot-panic-reboot, which don't occur with foreground fsck. And at least the first result is from 6.x. -- Bruce Cran So... Is the background fsck causing damage or corruption? The answer to that is NO. It's a consequence of reading a bad directory structure, which happened anyway. Quoting jpd on this same issue, emphasis added: So far we only have *your word* for *vague problems* and *speculated causes*. So your best bets so far are to investigate, and lending a hand to the fs people with ironing out a possible bug or two. Seriously, this conversation is full of crap, and only makes one of FreeBSDs incredibly useful features look bad with no evidence. Can no-one can come up with a reply either quoting a mailing list or giving the circumstances when: a) Background fsck caused data CORRUPTION _and_ b) A foreground fsck would not have done the same ? Anything else is sidestepping the question, and spreading FUD. Anyone? Perhaps I should CC one of the filesystem developers to get them to reassure you all? I don't think they'd be too pleased at people saying their design is flawed. It's not. Chris -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Apr 6, 2009, at 11:12, Chris Rees wrote: Can no-one can come up with a reply either quoting a mailing list or giving the circumstances when: a) Background fsck caused data CORRUPTION _and_ b) A foreground fsck would not have done the same ? Yes. When background FSCK first became standard I let it go that way on my production servers. The first time we had a power issue that resulted in a shutdown of a server it tried to come back up when the power was restored. I have a large number of daemons that rely on configure files and other information that is reasonably frequently updated. Some of those files were in the process of being updated when it shut down. As a result background FSCK did not get around to those files till much after the daemons were up and running (or trying to run). Most of them worked ok at the beginning. However after FSCK resolved the problems, the underlying files changed. The daemons couldn't function at that point. While a simple reboot at that point fixed everything, that caused yet another outage for users. Hence, I disabled background FSCK. There have been a few power issues since then and there have been no recovery issues with foreground FSCK other than the restart takes a bit longer. This is reproducible since it happened on several different servers. However, I am not about to go back and subject users to additional downtime when a viable workaround that avoids the problem exists. I doubt that the concept of background FSCK is broken and I suspect that the implementation is good too. The issue is that some services really should not be started till after FSCK (either variety) has completed. I didn't see an easy way to do that using rc. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
2009/3/31 Oliver Fromme o...@lurza.secnetix.de: Chris Rees utis...@googlemail.com wrote: 2009/3/31 Wojciech Puchar woj...@wojtek.tensor.gdynia.pl: IMHO this background fsck isn't good idea at all Why? Google background fsck damage. I was bitten by it myself, and I also recommend to turn background fsck off. If your disks are large and you can't afford the fsck time, consider using ZFS, which has a lot of benefits besides not requiring fsck. Best regards Oliver Right... You were bitten by background fsck, what _exactly_ happened? All the 'problems' here associated with bgfsck are referring to FreeBSD 4 etc, or incredibly vague anecdotal evidence. Have you googled for background fsck damage? Nothing (in the first two pages at least) even suggests that background fsck causes damage. Erik Trulsson wrote: Normal PATA/SATA disks with write caching enabled (which is the default) do not provide these guarantees. Disabling write caching on will make them adhere to the assumptions that soft updates make, but at the cost of a severe performance penalty when writing to the disks. In short therefore on a 'typical' PC you can fairly easily get errors on a filesystem which background fsck cannot handle. What do you mean by handle? Sure, it won't fix them, but it'll at least detect them. The chances of actually having a problem are slim, anyway, and it won't cause any damage either. Please don't assert information or stories about being 'bitten', without being more specific. It's meaningless and frustrating; I didn't ask who was bitten, I asked what the problem was. Also, please don't tell me to search the Internet without checking the search results for relevance yourself. I've spent a long time researching this, as have the FreeBSD devs, and they chose to make it on by default with no warnings. From the petty things they DO warn about, I very much doubt they'd allow something with a chance of any data corruption slide like that. Concrete evidence or direct links to problems with FreeBSD 6.0 ONLY in response please. Or, no-one has proven any reason for distrust, and all you lot are spreading is FUD. Sorry for the rant, it's not directly aimed at any of you, just the general assertion of 'facts' with no evidence, Chris -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
2009/4/5 Chris Rees utis...@googlemail.com: 2009/3/31 Oliver Fromme o...@lurza.secnetix.de: Chris Rees utis...@googlemail.com wrote: 2009/3/31 Wojciech Puchar woj...@wojtek.tensor.gdynia.pl: IMHO this background fsck isn't good idea at all Why? Google background fsck damage. I was bitten by it myself, and I also recommend to turn background fsck off. If your disks are large and you can't afford the fsck time, consider using ZFS, which has a lot of benefits besides not requiring fsck. Best regards Oliver Right... You were bitten by background fsck, what _exactly_ happened? All the 'problems' here associated with bgfsck are referring to FreeBSD 4 etc, or incredibly vague anecdotal evidence. Have you googled for background fsck damage? Nothing (in the first two pages at least) even suggests that background fsck causes damage. Erik Trulsson wrote: Normal PATA/SATA disks with write caching enabled (which is the default) do not provide these guarantees. Disabling write caching on will make them adhere to the assumptions that soft updates make, but at the cost of a severe performance penalty when writing to the disks. In short therefore on a 'typical' PC you can fairly easily get errors on a filesystem which background fsck cannot handle. What do you mean by handle? Sure, it won't fix them, but it'll at least detect them. The chances of actually having a problem are slim, anyway, and it won't cause any damage either. This is exactly my experience: maybe three times in years of various power failures and hardware barfs have I had the background fsck tell me to run fsck manually. And that is the entire extent of the failure. The system was running normally, if a bit slowly from the fsck itself, and the worst result was a disappeared /var/db/pkg directory (which had nothing to do with fsck being in the background on restart). -- -- ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Sun, 5 Apr 2009 21:40:52 +0100 Chris Rees utis...@googlemail.com wrote: 2009/3/31 Oliver Fromme o...@lurza.secnetix.de: Chris Rees utis...@googlemail.com wrote: 2009/3/31 Wojciech Puchar woj...@wojtek.tensor.gdynia.pl: IMHO this background fsck isn't good idea at all Why? Google background fsck damage. I was bitten by it myself, and I also recommend to turn background fsck off. If your disks are large and you can't afford the fsck time, consider using ZFS, which has a lot of benefits besides not requiring fsck. Best regards Oliver Right... You were bitten by background fsck, what _exactly_ happened? All the 'problems' here associated with bgfsck are referring to FreeBSD 4 etc, or incredibly vague anecdotal evidence. Have you googled for background fsck damage? Nothing (in the first two pages at least) even suggests that background fsck causes damage. http://www.google.co.uk/search?q=background+fsck+corruption You'll find the first few results are about panics during background fsck resulting in an endless cycle of boot-panic-reboot, which don't occur with foreground fsck. And at least the first result is from 6.x. -- Bruce Cran ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tuesday 31 March 2009 08:05:11 manish jain wrote: I am migrating from Linux and am still learning the basics of FreeBSD. One thing that I would to carry over from my Linux days is to force an fsck on all filesystems at system startup. On Linux, this was simply a matter of editing /etc/rc.sysinit. Things seem a bit more complicated in the BSD world. Can somebody please point me in the right direction ? fsck -p is done by default (meaning, filesystems are not fully scanned if they are marked clean). If pruning fails, background_fsck is checked, which will work on UFS systems with soft updates, but is not recommended by many as it may leave some errors unchecked. If background_fsck is set to NO, things will stop and operator intervention is required, unless one has set fsck_y_enable. All this logic is implemented in /etc/rc.d/fsck. The rc.conf(5) manpage and related rc(8), rcorder(8) and rc.subr(8) are a good read when migrating. -- Mel ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
manish jain wrote: Hi, I am migrating from Linux and am still learning the basics of FreeBSD. One thing that I would to carry over from my Linux days is to force an fsck on all filesystems at system startup. On Linux, this was simply a matter of editing /etc/rc.sysinit. Things seem a bit more complicated in the BSD world. Can somebody please point me in the right direction ? man fsck Traditionally, fsck is invoked before the file systems are mounted and all checks are done to completion at that time. If background checking is available, fsck is invoked twice. It is first invoked at the traditional time, before the file systems are mounted, with the -F flag to do check- ing on all the file systems that cannot do background checking. Also, you can set this in /etc/rc.conf fsck_y_enable=YES if you want to automatically run 'fsck -y' ... handy for remote servers. Oh, and if you use ZFS, there is no such thing as 'fsck'. That file system never needs fsck. :) If you want less fsck headaches on a big disk system, make the large partion (/home ?) ZFS. http://en.wikipedia.org/wiki/Zfs http://wiki.freebsd.org/ZFSQuickStartGuide Rudy ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, 31 Mar 2009 11:35:11 +0530 manish jain invalid.poin...@gmail.com wrote: Hi, I am migrating from Linux and am still learning the basics of FreeBSD. One thing that I would to carry over from my Linux days is to force an fsck on all filesystems at system startup. On Linux, this was simply a matter of editing /etc/rc.sysinit. Things seem a bit more complicated in the BSD world. Can somebody please point me in the right direction ? I found this from a post last year: echo '/sbin/fsck -y -f' /etc/rc.early -- Bruce Cran ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
i don't know why you do want to FORCE it every boot. in FreeBSD it's not needed. but you may add background_fsck=NO to check filesystems at boot when needed, not delayed. IMHO this background fsck isn't good idea at all ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, 31 Mar 2009 15:01:37 +0800, Bruce Cran br...@cran.org.uk wrote: On Tue, 31 Mar 2009 11:35:11 +0530 manish jain invalid.poin...@gmail.com wrote: Hi, I am migrating from Linux and am still learning the basics of FreeBSD. One thing that I would to carry over from my Linux days is to force an fsck on all filesystems at system startup. On Linux, this was simply a matter of editing /etc/rc.sysinit. Things seem a bit more complicated in the BSD world. Can somebody please point me in the right direction ? I found this from a post last year: echo '/sbin/fsck -y -f' /etc/rc.early You could also replace rc.early with rc.local if you want it to run later in the boot process. -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/ ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
2009/3/31 Wojciech Puchar woj...@wojtek.tensor.gdynia.pl: IMHO this background fsck isn't good idea at all Why? Chris -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
Bruce Cran wrote: On Tue, 31 Mar 2009 11:35:11 +0530 manish jain invalid.poin...@gmail.com wrote: Hi, I am migrating from Linux and am still learning the basics of FreeBSD. One thing that I would to carry over from my Linux days is to force an fsck on all filesystems at system startup. On Linux, this was simply a matter of editing /etc/rc.sysinit. Things seem a bit more complicated in the BSD world. Can somebody please point me in the right direction ? I found this from a post last year: echo '/sbin/fsck -y -f' /etc/rc.early Hi Bruce/Everyone else, Thanks for the rc.early tip. BTW, a lot of people who posted replies thought I was not aware that a preen is always executed at startup. When I said I wanted to force an fsck, I meant 'fsck -fy'. As for background checks, they are - in my opinion - a real nightmare. Even though I am just a learner on FreeBSD still, I can assure anyone, putting background_fsck=NO into your rc.conf is one of the best things you can do. As for the reason why I want to force fsck is that it has now happened 3 timed that, after a clean and proper shutdown - with no foreign filesystems mounted, FreeBSD has complained on system restart (twice on a 5.x distribution I had briefly used and now once on 7.1) that / was not properly unmounted. Having bgfsck enabled is like inviting a dragon to dinner when this happens. -- Thank you and Regards Manish Jain invalid.poin...@gmail.com +91-99830-62246 NB : Laast year I kudn't spell Software Engineer. Now I are won. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
2009/3/31 manish jain invalid.poin...@gmail.com: BTW, a lot of people who posted replies thought I was not aware that a preen is always executed at startup. When I said I wanted to force an fsck, I meant 'fsck -fy'. As for background checks, they are - in my opinion - a real nightmare. Even though I am just a learner on FreeBSD still, I can assure anyone, putting background_fsck=NO into your rc.conf is one of the best things you can do. As for the reason why I want to force fsck is that it has now happened 3 timed that, after a clean and proper shutdown - with no foreign filesystems mounted, FreeBSD has complained on system restart (twice on a 5.x distribution I had briefly used and now once on 7.1) that / was not properly unmounted. Having bgfsck enabled is like inviting a dragon to dinner when this happens. Sorry, but I have to disagree. The filesystem that FreeBSD uses (UFS to some, FFS to others) has a feature known as 'snapshots', something alien to people in the Linux world. What this means, is that one can take a 'snapshot' of a drive's state (somewhat like a versioning tag), and mount, dump, OR fsck it. The point of a background fsck is that the SNAPSHOT is fsck'd, and only if there is a problem (which there usually isn't, due to soft-updates meaning that data are rarely lost on power loss) does fsck require write access to the volume in question. This is also why you can dump a live filesystem in FreeBSD. Just to reiterate something said a thousand times, there is NOTHING WRONG with background fscks, and just because something doesn't work well for GNU/Linux doesn't mean it doesn't work with FreeBSD. There are many differences, after all. Chris -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, 31 Mar 2009 08:15:54 +0200 Mel Flynn mel.flynn+fbsd.questi...@mailing.thruhere.net wrote: On Tuesday 31 March 2009 08:05:11 manish jain wrote: I am migrating from Linux and am still learning the basics of FreeBSD. One thing that I would to carry over from my Linux days is to force an fsck on all filesystems at system startup. On Linux, this was simply a matter of editing /etc/rc.sysinit. Things seem a bit more complicated in the BSD world. Can somebody please point me in the right direction ? fsck -p is done by default (meaning, filesystems are not fully scanned if they are marked clean). If pruning fails, background_fsck is checked, which will work on UFS systems with soft updates, but is not recommended by many as it may leave some errors unchecked. I don't think that's quite right, fsck -p is only done if background_fsck=NO, otherwise an fsck -pF is done instead. The latter does an fsck -p on filesystems that aren't eligible for background checking - usually root and any none UFS filesystems. In other words you need to set background_fsck=NO to get a preen on all filesystems. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, 31 Mar 2009 16:00:18 +0530 manish jain invalid.poin...@gmail.com wrote: As for the reason why I want to force fsck is that it has now happened 3 timed that, after a clean and proper shutdown - with no foreign filesystems mounted, FreeBSD has complained on system restart (twice on a 5.x distribution I had briefly used and now once on 7.1) that / was not properly unmounted. Having bgfsck enabled is like inviting a dragon to dinner when this happens. If you've done a normal install, soft-updates aren't enabled on /, so it will get foreground checked by default. If I were you I'd reboot into single user mode and do a full fsck on it. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, 31 Mar 2009 16:00:18 +0530 manish jain invalid.poin...@gmail.com wrote: Having bgfsck enabled is like inviting a dragon to dinner when this happens. 2009/3/31 RW rwmailli...@googlemail.com: If you've done a normal install, soft-updates aren't enabled on /, so it will get foreground checked by default. If I were you I'd reboot into single user mode and do a full fsck on it. Seriously, why is everyone against background fsck? Can anyone give a good reason? Please? Chris -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, Mar 31, 2009 at 04:04:53PM +0100, Chris Rees wrote: On Tue, 31 Mar 2009 16:00:18 +0530 manish jain invalid.poin...@gmail.com wrote: Having bgfsck enabled is like inviting a dragon to dinner when this happens. 2009/3/31 RW rwmailli...@googlemail.com: If you've done a normal install, soft-updates aren't enabled on /, so it will get foreground checked by default. If I were you I'd reboot into single user mode and do a full fsck on it. Seriously, why is everyone against background fsck? Can anyone give a good reason? Please? For background fsck to work as it is supposed to, it is necessary that only certain errors can occur on the filesystem. Other types of errors cannot be corrected by a background fsck. To make sure that only the allowable errors can occur it is necessary for soft updates to be used and working as it is supposed to. For soft updates to work as it is supposed to the disk subsystem must provide certain guarantees on when and in which order blocks are written. Normal PATA/SATA disks with write caching enabled (which is the default) do not provide these guarantees. Disabling write caching on will make them adhere to the assumptions that soft updates make, but at the cost of a severe performance penalty when writing to the disks. In short therefore on a 'typical' PC you can fairly easily get errors on a filesystem which background fsck cannot handle. It is also the case that background fsck relies on snapshots to work, At least in the past snapshots had stability problems. Things are supposed to be better these days, but many people have long memories for these kind of problems. -- Insert your favourite quote here. Erik Trulsson ertr1...@student.uu.se ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tuesday 31 March 2009 14:24:11 RW wrote: On Tue, 31 Mar 2009 08:15:54 +0200 Mel Flynn mel.flynn+fbsd.questi...@mailing.thruhere.net wrote: On Tuesday 31 March 2009 08:05:11 manish jain wrote: I am migrating from Linux and am still learning the basics of FreeBSD. One thing that I would to carry over from my Linux days is to force an fsck on all filesystems at system startup. On Linux, this was simply a matter of editing /etc/rc.sysinit. Things seem a bit more complicated in the BSD world. Can somebody please point me in the right direction ? fsck -p is done by default (meaning, filesystems are not fully scanned if they are marked clean). If pruning fails, background_fsck is checked, which will work on UFS systems with soft updates, but is not recommended by many as it may leave some errors unchecked. I don't think that's quite right, fsck -p is only done if background_fsck=NO, otherwise an fsck -pF is done instead. The latter does an fsck -p on filesystems that aren't eligible for background checking - usually root and any none UFS filesystems. As far as I can tell, -F -p skips clean disks (-p) and defers to background when possible, though the manpage doesn't exclude your or my theory. ENOTIME to check the source. -- Mel ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
Chris Rees utis...@googlemail.com wrote: 2009/3/31 Wojciech Puchar woj...@wojtek.tensor.gdynia.pl: IMHO this background fsck isn't good idea at all Why? Google background fsck damage. I was bitten by it myself, and I also recommend to turn background fsck off. If your disks are large and you can't afford the fsck time, consider using ZFS, which has a lot of benefits besides not requiring fsck. Best regards Oliver -- Oliver Fromme, secnetix GmbH Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd With Perl you can manipulate text, interact with programs, talk over networks, drive Web pages, perform arbitrary precision arithmetic, and write programs that look like Snoopy swearing. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, 31 Mar 2009 18:57:21 +0200 (CEST), Oliver Fromme o...@lurza.secnetix.de wrote: Google background fsck damage. I was bitten by it myself, and I also recommend to turn background fsck off. If your disks are large and you can't afford the fsck time, consider using ZFS, which has a lot of benefits besides not requiring fsck. You can always ask yourself: What is more important, the boot-up time or my data? In any case, I'd recommend to emphasize the importance of the data, so even with larger UFS disks, it's okay to wait a bit, but then be sure that nothing is damaged. Furthermore, I agree with the recommendation of ZFS. If your hardware is good enough (which shouldn't be a problem today), ZFS handles possible data damages much better and faster. -- Polytropon From Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ... ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Question about forcing fsck at boottime
On Tue, 31 Mar 2009 17:36:32 +0200 Mel Flynn mel.flynn+fbsd.questi...@mailing.thruhere.net wrote: On Tuesday 31 March 2009 14:24:11 RW wrote: On Tue, 31 Mar 2009 08:15:54 +0200 Mel Flynn mel.flynn+fbsd.questi...@mailing.thruhere.net wrote: somebody please point me in the right direction ? fsck -p is done by default (meaning, filesystems are not fully scanned if they are marked clean). If pruning fails, background_fsck is checked, which will work on UFS systems with soft updates, but is not recommended by many as it may leave some errors unchecked. I don't think that's quite right, fsck -p is only done if background_fsck=NO, otherwise an fsck -pF is done instead. The latter does an fsck -p on filesystems that aren't eligible for background checking - usually root and any none UFS filesystems. As far as I can tell, -F -p skips clean disks (-p) and defers to background when possible, though the manpage doesn't exclude your or my theory. ENOTIME to check the source. I wouldn't dispute that clean filesytems are skipped, it's just that you seemed to be implying that every filesystem gets a foreground fsck -p. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
