Does PCLinuxOS 2010 auto-check or self-check disk for errors???

[eor2004]

Hello friends, as the subject says, I want to know if pc linux 2010 has an automatic function on self checking the disk for errors like other distros do when booting the OS???

[Old-Polack]

Hello friends, as the subject says, I want to know if pc linux 2010 has an automatic function on self checking the disk for errors like other distros do when booting the OS???

It's Linux, so all distros have that capability. How you have the various options configured is up to you.

[muungwana]

The question should not be if the capability is there, but if it is enabled by default and with what options if it is

tune2fs command can be used to modify when the file systems should be checked if they are to be checked at all. There are other ways of forcing a file system check if you want them checked before specified time is reached.

It will be better if you said what you want to do and people can help you out. I know the command can be used to set options but it doesnt seem to show what options are already there if you just want to check them out

more info on the command can be found here: http://linux.die.net/man/8/tune2fs

[Zero Angel]

Hello friends, as the subject says, I want to know if pc linux 2010 has an automatic function on self checking the disk for errors like other distros do when booting the OS???

I believe PCLOS will automatically check the filesystem for errors after every certain number of boots, or if the filesystem is flagged as dirty (ie: from an improper shutdown)

[johnmart]

This may be  point of semantics, but isn't the filesystem check done by the kernel according to your type of filesystem--at the kernel level? fsck cleans up filesystem errors at the desktop environment level. I'd appreciate knowing if I understand it correctly. 

But as other posters said yes, & in a variety of ways.
John

[Old-Polack]

Hello friends, as the subject says, I want to know if pc linux 2010 has an automatic function on self checking the disk for errors like other distros do when booting the OS???

I believe PCLOS will automatically check the filesystem for errors after every certain number of boots, or if the filesystem is flagged as dirty (ie: from an improper shutdown)

Unless there has been a recent change, automatic checking by time or boot count has not been set by default during the PCLinuxOS installation. The capacity is there, but needs to be set by each individual to their own taste. To see how my / partition is set, currently;

[root@littleboy ~]# tune2fs -l LABEL=kde2010
tune2fs 1.41.12 (17-May-2010)
Filesystem volume name:   kde2010
Last mounted on:          /
Filesystem UUID:          f5b15060-9731-4dd8-9250-3d347b883295
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash
Default mount options:    user_xattr
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              2101232
Block count:              8389938
Reserved block count:     419496
Free blocks:              6171162
Free inodes:              1884233
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      1021
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8176
Inode blocks per group:   511
Flex block group size:    16
Filesystem created:       Sun May  9 17:47:26 2010
Last mount time:          Fri Jul  2 08:13:59 2010
Last write time:          Thu Jul  1 04:50:19 2010
Mount count:              9
Maximum mount count:      28
Last checked:             Wed Jun 23 09:06:06 2010
Check interval:           15552000 (6 months)
Next check after:         Mon Dec 20 08:06:06 2010
Lifetime writes:          53 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:               256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
First orphan inode:       1180265       <-- I have at least one orphan inode, from an app crash.
Default directory hash:   half_md4
Directory Hash Seed:      c40d26f6-cfb7-4c61-b4f2-9a17ba8e5b1a
Journal backup:           inode blocks

The orphan inode will be removed on next boot, the file system will be checked after every 28 boots, and it's been mounted 9 times since the last check. It will also be checked every 6 months, regardless of the mount counts.

[Old-Polack]

This may be  point of semantics, but isn't the filesystem check done by the kernel according to your type of filesystem--at the kernel level? fsck cleans up filesystem errors at the desktop environment level. I'd appreciate knowing if I understand it correctly. 

But as other posters said yes, & in a variety of ways.
John

It is not the kernels job to check filesystems; that's fsck's job. There is no "desktop environment level" in filesystem checking. There is inode level filesystem checking, as well as options to check for bad blocks, and there are applications to totally wipe partitions of any filesystem information, before formatting to whichever filesystem one desires. This is all part of the original Unix/Linux premise, many small apps, each doing only one job, but doing that job extremely well.

[johnmart]

Thanks old-polack. I was pretty off track from the OP subject but your explanation helps.

I have noticed a few times my file system getting checked while I watched the graphical startup. I never setup tune2fs. Is there some filesystem check from another source every 20 starts or after a crash or something?
I thought linux kernels were self defragging & error checking. Is that different than what eor2004 asked about?
My apologies for hijacking eor2004s post.   
Thanks old-polack for your clear explanations.

[Old-Polack]

Thanks old-polack. I was pretty off track from the OP subject but your explanation helps.

I have noticed a few times my file system getting checked while I watched the graphical startup. I never setup tune2fs. Is there some filesystem check from another source every 20 starts or after a crash or something?
I thought linux kernels were self defragging & error checking. Is that different than what eor2004 asked about?
My apologies for hijacking eor2004s post.   
Thanks old-polack for your clear explanations.

If the filesystem is marked as dirty, meaning some error has been found within the filesystem, it will be checked at next boot, before mounting.

You keep referring to kernels where the proper term would be filesystem. Kernels do not fragment, though filesystems might, and the degree of fragmentation that might occur depends both on conditions and basic design of the filesystem in question. All filesystems have the ability to fragment as part of their design. If they did not, any data one tried to save that was larger than the largest contiguous block of inodes available, would be either lost, or the system as a whole would lock up, unable to proceed to the next task. The closer to being full it is, the more likely a filesystem will be to fragment the saved files. As a general rule, Linux filesystems will not fragment unless there is an absolute need to.

[johnmart]

o-p quote: You keep referring to kernels where the proper term would be filesystem. Kernels do not fragment....

Sorry, what I meant to say was that the kernel was performing a cleanup or defrag of the filesystem. What I was getting at was, what was performing the action & what triggered it? So, if there is an error in the filesystem will it be automatically detected or do you need to enable & configure tune2fs? (or wait for some trouble to surface)

Also, with my reference to desktop level action, I meant to highight the difference between a cleanup action before the desktop loaded which I assumed would be performed by or triggered by the kernel, as opposed to an application from the desktop environment.
Sorry for my imprecise question & terminology. Guess I am way outta my depth here.
Thanks, old-polack

[Old-Polack]

o-p quote: You keep referring to kernels where the proper term would be filesystem. Kernels do not fragment....

Sorry, what I meant to say was that the kernel was performing a cleanup or defrag of the filesystem. What I was getting at was, what was performing the action & what triggered it? So, if there is an error in the filesystem will it be automatically detected or do you need to enable & configure tune2fs? (or wait for some trouble to surface)

Also, with my reference to desktop level action, I meant to highight the difference between a cleanup action before the desktop loaded which I assumed would be performed by or triggered by the kernel, as opposed to an application from the desktop environment.
Sorry for my imprecise question & terminology. Guess I am way outta my depth here.
Thanks, old-polack

The action is carried out by fsck (file system check). Asking if the kernel does this is like asking if the CEO of a major corporation sweeps the floor when they get trashy. I say the janitor does that, and you keep asking if the CEO takes care of this. Just as the CEO is highly unlikely to even know the janitor, other than to see him walk by in the hallway, the kernel is only vaguely aware of fsck.

The kernel is only involved to the extent of running the system. Individual tasks are performed by the application designed for the task. Scripts may call them, users may call them, preset conditions may call them. The kernel on it's own does not call them. That's not the kernels job. Likewise, tune2fs may set the schedule by which the filesystem will be checked, but it does not check the filesystem. That's fsck's job.

Filesystem checks need to be done on unmounted filesystems. You could do an fsck from the liveCD on your / partition, as it can't be unmounted from a running system. Your /home partition could be unmounted by root, and checked from a running installed system. Any data partitions could be unmounted and checked from the running system. Your / partition needs to be checked from a different running system, like the liveCD.

[muungwana]

johnmart,
the file system is responsible for managing files on a partition/hard drive, not the kernel. When the system boot, fsck(not the kernel) reads "/etc/fstab" text file to find out how many partitions are on the system and check all file systems for errors before those file systems are mounted.This checking for errors has nothing to do with the desktop environment or the kernel and it is performed at boot time.

If the file system is corrupted, the corruption will be noticed by fsck(not the kernel) when the file system is checked most of the time when the system is next booted up(if the system is configured to check file systems at boot up). A user can manually check the file system at runtime by first unmounting the file system and then manually run the command pointing it at a file system to be checked. Since the partition need to be unmounted first, a root partition cannot be checked when the system is running.

fsck just peek at the file system at boot time to check for errors and it usually notices only the serious only and forces a comprehensive check of the file system.

"tune2fs"(not kernel) can set options for "fsck"(not kernel) in partitions telling it to do a comprehensive test of the file system even if the peek doesnt show any errors after a certain amount of mounts are done or after a certain period of time have passed.

[johnmart]

old-polack & muungwana:

Thank you for very clear & helpful explanations. Guess I am denser than the OP. Now I get it.

[sixthwheel]

Very informative topic.
Think of the kernel as the CEO...Makes sense.