Sponsored Content
Full Discussion: Is umount -l dangerous?
Operating Systems Linux Is umount -l dangerous? Post 302353507 by Corona688 on Tuesday 15th of September 2009 01:07:26 PM
Old 09-15-2009
That's not accurate either. I went and tested it before spouting off, you know...

Users who have open directories are not stopped from traversing them, opening files in them, writing things in files, or perhaps even creating files. In other words, a lazy unmount doesn't do anything at all to the filesystem until it's free -- it just fakes it. That is, it denies access to a mounted filesystem until everyone closes all references to it. That's pretty much the worst of both worlds: It's mounted, so you can't do a thing to the devices, but it acts like its offline and denies everyone access. If the administration couldn't quickly find whatever reference is plugging up the unmount, they really would have to reboot the machine, it's either that or send the people who need to use that partition home for the day.

It wouldn't be so bad if there was a way to cancel a lazy unmount...

Last edited by Corona688; 09-15-2009 at 02:21 PM..
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

umount

:confused: Twofold question for you unix "guru's" 1) When attempting to use the umount command I get a message stating that the partition that I want to unmount is busy. Is there another command that I need to use prior to the umount command to clear the partition of activity????? ... (2 Replies)
Discussion started by: rod23
2 Replies

2. UNIX for Dummies Questions & Answers

umount error

the program as follow: mount /dev/fd0135ds18 /mnt cd /mnt touch file1 cat /file2 >/mnt/file1 umount /dev/fd135ds18 when error tell device busy could you tell me the reason? (1 Reply)
Discussion started by: fresh
1 Replies

3. UNIX for Advanced & Expert Users

umount help

hi all, I inherit a Solaris7 system with /home mounted via a share from the NFS server. When I look at mnttab, there are two entries mounted under /home. Let's say they are server:/home/a and server:/home/b. I would like to maintain /home/a but not /home/b. However, I just don't know where... (4 Replies)
Discussion started by: andrec
4 Replies

4. UNIX for Dummies Questions & Answers

List of dangerous Unix command

Hi Guys, I wonder if one of you would have a list of dangerous commands on unix. Regards (8 Replies)
Discussion started by: JBB873
8 Replies

5. Solaris

umount is failing

I am trying to umount a NFS share. When I do the following: # umount syrupg21 umount: /oebs/syrupg21: device is busy device bussy so I like to check what is working on the system.... # fuser -muv /oebs/syrupg21/ # So no locks should be there... any clue? Regards, Johan... (3 Replies)
Discussion started by: suntac
3 Replies

6. HP-UX

how to force umount

sorry, wrong section, mod please close thread (0 Replies)
Discussion started by: robertngo
0 Replies

7. UNIX for Dummies Questions & Answers

accidentally umount -a

Hi all, I accidentally unmounted filesystems using umount -a command. How to recover from this. Please help. Thanks in advance! when i try to use mount -a i got the following output. # mount -a mount: /dev/vg00/lvol05 already mounted or /opt busy mount: /dev/vg00/lvol07 already... (4 Replies)
Discussion started by: lramsb4u
4 Replies

8. UNIX for Dummies Questions & Answers

Umount CIFS

hi guys I have to umount a CIFS from a Windows machine...but it's been imposible there is one special task /sbin/umount.cifs /mondobackup that task cannot be kill...so I cannot umount the unit any idea how to kill this and umount this CIFS share? by the way I've tried umount... (5 Replies)
Discussion started by: kopper
5 Replies

9. Shell Programming and Scripting

List of dangerous shell commands

Hello, I have a Application which needs to run shell scripts in a elevated state (root) for system interrogation. So I execute each script using bash -C. This has worked really well. I now want to add another layer of security, I cant inspect each of the scripts before they get deployed to the... (4 Replies)
Discussion started by: tjones1105
4 Replies

10. War Stories

Dangerous rm -rf command

Hello All, I am posting a intresting story which is posted by Mark Brader but actual story is from Mario Wolczko. Original link is here Thanks, R. Singh (4 Replies)
Discussion started by: RavinderSingh13
4 Replies
UMOUNT(8)						    BSD System Manager's Manual 						 UMOUNT(8)

NAME
umount -- unmount filesystems SYNOPSIS
umount [-fv] special | node umount -a | -A [-fv] [-h host] [-t type] DESCRIPTION
The umount command calls the unmount(2) system call to remove a special device or the remote node (rhost:path) from the filesystem tree at the point node. If either special or node are not provided, the appropriate information is taken from the list of filesystems provided by getfsent(3). The options are as follows: -a All the filesystems described via getfsent(3) are unmounted. -A All the currently mounted filesystems except the root are unmounted. -f The filesystem is forcibly unmounted. Active special devices continue to work, but all other files return errors if further accesses are attempted. The root filesystem cannot be forcibly unmounted. -h host Only filesystems mounted from the specified host will be unmounted. This option implies the -A option and, unless otherwise speci- fied with the -t option, will only unmount NFS filesystems. -t type Is used to indicate the actions should only be taken on filesystems of the specified type. More than one type may be specified in a comma separated list. The list of filesystem types can be prefixed with ``no'' to specify the filesystem types for which action should not be taken. For example, the umount command: umount -A -t nfs,hfs umounts all currently-mounted filesystems of the type NFS and HFS. (The -a option only unmounts entries in the /etc/fstab list.) -v Verbose, additional information is printed out as each filesystem is unmounted. NOTES
Due to the complex and interwoven nature of Mac OS X, umount may fail often. It is recommended that diskutil(1) (as in, ``diskutil unmount /mnt'') be used instead. SEE ALSO
unmount(2), getfsent(3), mount(8), diskutil(1) HISTORY
A umount command appeared in Version 6 AT&T UNIX. 4th Berkeley Distribution May 8, 1995 4th Berkeley Distribution
All times are GMT -4. The time now is 10:50 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy