Fstab – What Does the Noload Option Do?

fstab

I put UUID=fb2b6c2e-a8d7-4855-b109-c9717264da8a / ext4 auto,noatime,noload,data=ordered,commit=10,defaults 1 1 in fstab

And now server fails to reboot. It can reboot but reject all kind of connections.

This is what my provider said:

Yeah, the noload option might be problematic... I can't edit /etc/fstab from
single user mode, but I might be able to edit it using one of my pxe boot tools
to enter the filesystem manually. With regards to your request about
/var/log/messages and /var/log/secure, I'm afraid I can't do that for you
(technically, I'm already bordering on managed services by editing your fstab
for you, but I am justifying it as necessary to restore connectivity)...

I search for the purpose of noload option in google

https://www.google.com/search?q=fstab+noload&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

and have no issue. Someone in linux forum says that it disable journaling.

I'm unable to paste the actual error messages without manually typing
them out, but I assure you they're not really very descriptive
(basically, system indicates that it is unable to remount root in
read/write mode, and then errors composed of read/write problems,
particularly in /var are printed to the screen)…

It does end in a happy ending:

Your server is back online, and I was able to successfully disable
your iptables (which for reference, I did confirm were causing
connectivity issues), and I am now able to ssh into your server with
the credentials provided earlier in this ticket:

Best Answer

noload doesn't turn off journaling. It suppresses the loading of the journal, without turning off journaling. As you can imagine, that's usually not a good thing.

noload is mostly useful to mount a disk as read-only without changing it in the slightest way, not even replaying the journal. You can read most data this way, and you can even read all data if the journal was flushed (by calling sync). For example, this is a way of reading from a filesystem that is currently mounted by a hibernated system.

noload may or may not be the cause of your problem, but in any case it's a very bad idea, and definitely not something to use in /etc/fstab.

SysV Init

The /etc/init.d/mountall.sh init script mounts local filesystems only:

mount -a -t nonfs,nfs4,smbfs,cifs,ncp,ncpfs,coda,ocfs2,gfs,gfs2,ceph -O no_netdev

Other filesystems are mounted by separate init scripts, like for example /etc/init.d/mountnfs.sh, which declare (via LSB headers) their dependency on $network. Thus these get scheduled later, after the network is brought up, while mountall.sh can run much earlier.

systemd

Local mount units are pulled in by local-fs.target, remote ones by remote-fs.target. systemd-fstab-generator scans /etc/fstab, generates mount units and assigns these to the above targets based on conditions similar to the above.

delay_connect

This option means that sshfs will not initiate the SSH connection to the remote server at mount time, but will only do so on the first filesystem operation actually requiring it. This delays error reporting, but might be a useful workaround in some cases, for example if your init system hasn't got enough information to order the mount operation correctly. "The network" being "up" is a rather loose term, and even though one can add arbitrary extra dependencies to mount units that doesn't help if the trigger event is not part of the bootup transaction (in systemd parlance).

Do You Need to Specify the Defaults Option in fstab?

You only need defaults if the field would otherwise be empty.

You can leave out the options field altogether if it's empty, unless the 5th or 6th fields are present. Field 5 is the dump frequency, rarely used nowadays. Field 6 fsck order, should be 1 for /, 2 for other filesystems mounted on boot and 0 otherwise. Fields 5 and 6 can be omitted if their value is 0, except that field 5 needs to be present if field 6 is.

Thus defaults is necessary in

/dev/foo /foo somefs defaults 0 1

(though you can use some other option like rw or ro instead)

But it can be omitted when you specify another option.

eg: The mounts below have the same effect.

/dev/foo /foo somefs ro            0 1
/dev/foo /foo somefs defaults,ro   0 1

But these also have the same effect.

/dev/foo /foo somefs defaults      0 0
/dev/foo /foo somefs

Best Answer

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Do You Need to Specify the Defaults Option in fstab?

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