From: Les Mikesell Sent: April 21, 2015 09:19> > Why do you care about running them at the same time when it doesn't > take longer to run them all in parallel? Except I think the root > filesystem normally runs first. So you might want to stagger it vs. > everything else.I am trying to avoid running them at the same time in an effort to avoid 70 minute boot times (which is what happened on the weekend). I accept that fscks are required on a periodic basis and I am willing to reboot more often to achieve these but I would like to minimize downtime (during the reboot) where possible.> And unless you reboot frequently you are probably hitting the time > setting, not the mount count.This is in fact what transpired on the weekend and I would leave this in place as a protective measure. Regards, Hugh -- Hugh E Cruickshank, Forward Software, www.forward-software.com
On Tue, Apr 21, 2015 at 11:40 AM, Hugh E Cruickshank <hugh at forsoft.com> wrote:> From: Les Mikesell Sent: April 21, 2015 09:19 >> >> Why do you care about running them at the same time when it doesn't >> take longer to run them all in parallel? Except I think the root >> filesystem normally runs first. So you might want to stagger it vs. >> everything else. > > I am trying to avoid running them at the same time in an effort to > avoid 70 minute boot times (which is what happened on the weekend).How many filesystems do you have? If you look at ./etc.fstab, everything where the final number is '1' (normally just the root filesystem) should complete first, then everything with a 2 will run at once. If the other mounts are each on different drive/spindles they won't conflict with each other and will complete in the same time as running just the largest one of them. If you are running fscks of partitions on the same drive in parallel it will obviously go slower. -- Les Mikesell lesmikesell at gmail.com
On 04/21/2015 09:40 AM, Hugh E Cruickshank wrote:> I accept that fscks are required on a periodic basis and I am willing > to reboot more often to achieve these but I would like to minimize > downtime (during the reboot) where possible.Why do you accept that? The default behavior for filesystems set up by Red Hat tools (anaconda) is not to fsck. Not by mount count, nor by time. The default behavior for e2fsprogs was changed to disable periodic fsck in Feb 2011. CentOS 6 includes a version of e2fsprogs from before that change, but the filesystem is considered very stable, and the periodic fsck is not generally considered necessary.
From: Les Mikesell Sent: April 21, 2015 09:54> On Tue, Apr 21, 2015 at 11:40 AM, Hugh E Cruickshank wrote: > > > > I am trying to avoid running them at the same time in an effort to > > avoid 70 minute boot times (which is what happened on the weekend). > > How many filesystems do you have?It varies from system to system but is typically 8-10.> If you look at ./etc.fstab, > everything where the final number is '1' (normally just the root > filesystem) should complete first, then everything with a 2 will run > at once. If the other mounts are each on different drive/spindles > they won't conflict with each other and will complete in the same time > as running just the largest one of them. If you are running fscks of > partitions on the same drive in parallel it will obviously go slower.I am aware of that. With the exception of /, /boot and /home which are on one spindle (actually a hardware mirrored pair) the remaining filesystems are on separate drives (actually hardware mirrored pairs or RAID 10 arrays). The largest of the filesystems (four of them) share a common SAS controller, data channel and external disk array hardware (HP D2600) so running these in parallel might not be as effective as they could be. Regards, Hugh -- Hugh E Cruickshank, Forward Software, www.forward-software.com
From: Gordon Messmer Sent: April 21, 2015 10:30> > On 04/21/2015 09:40 AM, Hugh E Cruickshank wrote: > > I accept that fscks are required on a periodic basis and I > am willing > > to reboot more often to achieve these but I would like to minimize > > downtime (during the reboot) where possible. > > Why do you accept that?Every article I have read on the subject has recommended this a good practice.> The default behavior for filesystems set up by Red Hat tools > (anaconda) is not to fsck. Not by mount count, nor by > time. The default behavior for e2fsprogs was changed to disable > periodic fsck in Feb 2011. CentOS 6 includes a version of e2fsprogs > from before that change, but the filesystem is considered > very stable, > and the periodic fsck is not generally considered necessary.I have confirmed that filesystems setup by anaconda on both CentOS 6 and RHEL 6 have both boot count and interval disabled however they are not disabled for any manually created filesystems (they are set to 24 and 6 months, respectively). I find it interesting that as late as 2014 Red Hat is recommending: . If automatic filesystem checks are inconvenient, then it is recommended to disable the automated filesystem check as discussed in the following article: How to turn off forced/automatic fsck in Red Hat Enterprise Linux? . Once disabled, it is recommended to schedule regular "human controlled/monitored" filsystem checks, when it is convenient to do so. These checks should not be ignored, or scheduled too far apart. This is from https://access.redhat.com/solutions/70531 Regards, Hugh -- Hugh E Cruickshank, Forward Software, www.forward-software.com