FAQ
Hello


I am using 64 bit CentOS 6.4 on an i7 laptop with one sata drive and a
CD drive.
I installed CentOS by manually partitioning sda as:
sda1 as /boot, sda2 as swap, sda3 as /.
The booted system works great.


When I insert an external USB drive, formatted as ext3, the hard drive
on the laptop and the
USB drive are either sda or sdb, depending upon the order on which I
insert the USB drive
and boot the system. Please see the two mount commands below for each
of these situations.


This seems to work in either order except for the fact that I don't want
my USB drive to automount.


What I want is that after I insert the USB drive in a running system and
wait 15 seconds, I want to
mount the USB drive with the command "# mount /mnt". To accomplish this
I added a line to /etc/fstab but it didn't work.
When I uncomment the last line in fstab (see below) the computer hangs
and doesn't boot. I was successful with this strategy on a
similar laptop with Fedora 18 but not my current one.


Thank you,
Joe Hesse


=======================================================================================

The following mount command was issued by first completely booting
CentOS and then inserting the external USB Drive.
Note the sda3 is / and sda1 is /boot.


[root at XoticPC ~]# mount
/dev/sda3 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,modeb0)
tmpfs on /dev/shm type tmpfs (rw)
/dev/sda1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/dev/sdb1 on /media/GoFlex type ext3 (rw,nosuid,nodev,uhelper=udisks)


=======================================================================================

The following mount command was issued by inserting the external USB
drive in a powered down computer and then booting.
Note the sdb3 is / and sdb1 is /boot.


[root at XoticPC ~]# mount
/dev/sdb3 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,modeb0)
tmpfs on /dev/shm type tmpfs (rw)
/dev/sdb1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/dev/sda1 on /media/GoFlex type ext3 (rw,nosuid,nodev,uhelper=udisks)


=======================================================================================

The /etc/fstab file was generated by the install process. The commented
line at the bottom was added by me in an unsuccessful attempt to
be able to insert the USB drive in a booted computer, not having it
mount, and then control the mounting with "# mount /mnt".
The last UUID is the UUID of sdb1 determined with the command "# blkid
/dev/sdb1".


# /etc/fstab
UUID7606b7-46b8-4b29-9a4e-a50a1f6a1759 / ext4 defaults 1 1
UUIDàfdfeb1-e7a7-4a06-b5fa-7730c3c2e60d /boot ext4 defaults 1 2
UUIDÐe3c2ee-7c66-4d13-b387-1da958020b1a swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,modeb0 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
#UUID;550884-8d05-41a5-a205-17b6d7269dd1 /mnt ext3
rw,suid,dev,exec,noauto,nouser,async 0 2

Search Discussions

  • Jay Leafey at Jul 4, 2013 at 5:58 pm

    On 07/04/2013 10:46 AM, Joseph Hesse wrote:
    Hello

    I am using 64 bit CentOS 6.4 on an i7 laptop with one sata drive and a
    CD drive.
    I installed CentOS by manually partitioning sda as:
    sda1 as /boot, sda2 as swap, sda3 as /.
    The booted system works great.

    When I insert an external USB drive, formatted as ext3, the hard drive
    on the laptop and the
    USB drive are either sda or sdb, depending upon the order on which I
    insert the USB drive
    and boot the system. Please see the two mount commands below for each
    of these situations.

    This seems to work in either order except for the fact that I don't want
    my USB drive to automount.

    What I want is that after I insert the USB drive in a running system and
    wait 15 seconds, I want to
    mount the USB drive with the command "# mount /mnt". To accomplish this
    I added a line to /etc/fstab but it didn't work.
    When I uncomment the last line in fstab (see below) the computer hangs
    and doesn't boot. I was successful with this strategy on a
    similar laptop with Fedora 18 but not my current one.

    Thank you,
    Joe Hesse

    I have had similar issues in the past. The take-away is that you cannot
    depend on device names being stable, it depends on the order in which
    devices are enumerated at boot time.


    In my case, an eSATA drive shows up as the first device if it is turned
    on when the system boots. It apparently enumerates as sda and the rest
    of the drives are bumped up one drive letter. The system boots OK, but
    the drive letters are different.


    When I want to mount the external drive I use "LABEL=". When I
    formatted the external drive I specified a filesystem label and rather
    than specifying "/dev/sdb1" in my fstab I used "LABEL=fslabel". That
    way it doesn't matter what device name comes up, it mounts the
    filesystem by that label. The label can be added after-the-fact using
    tune2fs or the appropriate tool for the on-disk format. You can also
    use "UUID=<uuid>" if you prefer to use UUIDs. See the "mount" manpage
    for more information.


    Of course, I could be wrong about what you are trying to accomplish, but
    I think it might be applicable. YMMV!
    --
    Jay Leafey - jay.leafey at mindless.com
    Memphis, TN

Related Discussions

Discussion Navigation
viewthread | post
Discussion Overview
groupcentos @
categoriescentos
postedJul 4, '13 at 3:46p
activeJul 4, '13 at 5:58p
posts2
users2
websitecentos.org
irc#centos

2 users in discussion

Jay Leafey: 1 post Joseph Hesse: 1 post

People

Translate

site design / logo © 2022 Grokbase