Newbie question about fsck and mount

postcd · 07-06-2016, 02:48 AM

Hello,

i have 2 drives in HW raid 1. This is fstab:

Quote:

/dev/mapper/vg-root / ext4 discard,noatime 1 1
UUID=2ab84f72-7ace-4849-b911-c04fcf526b54 /boot ext2 defaults 1 2
/dev/mapper/vg-tmp /tmp ext4 discard,noatime 1 2
/dev/mapper/vg-swap swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0

# parted /dev/sda 'print'

Quote:

Model: Dell VIRTUAL DISK (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 263MB 262MB primary ext2 boot
2 263MB 1000GB 999GB primary lvm

Its a server that is running non-stop. I assume i do not need to run fsck or any such program on the filesystem/drive? I read i need to unmount filesystem before i run it (fsck /dev/sda). What would happen if i not unmount it?

If i unmount like: umount /dev/sda and then mount /dev/sda , will the partitions/filesystems return in same state before umount or i need to take a note of something before unmounting?

syg00 · 07-06-2016, 03:25 AM

Quote:

Originally Posted by postcd

I assume i do not need to run fsck or any such program on the filesystem/drive?

Why then are you raising this query ?.

Quote:

I read i need to unmount filesystem before i run it (fsck /dev/sda). What would happen if i not unmount it?

Why have you not read the manpage for fsck.ext4 ?.

Quote:

If i unmount like: umount /dev/sda and then mount /dev/sda , will the partitions/filesystems return in same state before umount or i need to take a note of something before unmounting?

You cannot umount the root.

TB0ne · 07-06-2016, 08:21 AM

Quote:

Originally Posted by postcd

Hello,
i have 2 drives in HW raid 1. This is fstab:

Code:

/dev/mapper/vg-root / ext4 discard,noatime 1 1
UUID=2ab84f72-7ace-4849-b911-c04fcf526b54 /boot ext2 defaults 1 2
/dev/mapper/vg-tmp /tmp ext4 discard,noatime 1 2
/dev/mapper/vg-swap swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0

# parted /dev/sda 'print'

Code:

Model: Dell VIRTUAL DISK (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 263MB 262MB primary ext2 boot
2 263MB 1000GB 999GB primary lvm

Its a server that is running non-stop. I assume i do not need to run fsck or any such program on the filesystem/drive? I read i need to unmount filesystem before i run it (fsck /dev/sda). What would happen if i not unmount it?

If i unmount like: umount /dev/sda and then mount /dev/sda , will the partitions/filesystems return in same state before umount or i need to take a note of something before unmounting?

A 'newbie' question...after you've been here for years, and been asking about mounting/fsck/raid/disk status for at least two?
http://www.linuxquestions.org/questi...ed-4175528660/
http://www.linuxquestions.org/questi...io-4175523763/
http://www.linuxquestions.org/questi...ll-4175505865/
http://www.linuxquestions.org/questi...ck-4175501524/

If you know how to check your RAID status and disk health, you then know if you need to run fsck. Again, since you've been using Linux for years now, and been asking such questions for years, this is hardly a 'newbie' thing for you. What are you confused about? If you tried running fsck on a mounted file system, it will warn you that it's not a good thing, and you can find MANY pages of documentation telling you this as well, with a simple search, as well as what will happen if you do NOT unmount a file system before running fsck. And, since the program itself is *ON* the root partition...how do you think you'll be able to run it, if you UNMOUNT it, and make it unavailable?

A brief Google search for "how to automatically run fsck on centos" pulls up, as the VERY FIRST HIT:
http://www.cyberciti.biz/faq/linux-f...boot-sequence/

...a way to force your system to run fsck upon a reboot. You don't typically need to run it, unless you're getting errors...which you already know how to check for, based on your previous threads.

sundialsvcs · 07-06-2016, 08:43 AM

This is one compelling reason for using logical volumes.

A volume cannot be checked if it is mounted. Filesystem integrity checks that occur at boot-time take place in a special system state that was purposely contrived to support it.