Bug 593784

Summary:	RHEL6 installer mounts-by-UUID not label / labels are on filesystems, not partitions
Product:	Red Hat Enterprise Linux 6	Reporter:	Steve Bonneville <sbonnevi>
Component:	doc-Storage_Admin_Guide	Assignee:	Don Domingo <ddomingo>
Status:	CLOSED CURRENTRELEASE	QA Contact:	ecs-bugs
Severity:	high	Docs Contact:
Priority:	low
Version:	6.0	CC:	jskeoch
Target Milestone:	rc	Keywords:	Documentation
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2010-11-11 15:36:26 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	561597

Description Steve Bonneville 2010-05-19 17:04:40 UTC

Description of problem:

RHEL 6 Storage Administration Guide, section 16.2.3 incorrectly claims that
we want to label the partition; what we're really labelling is the *filesystem* on the partition, which is an important distinction.

Also, the supplementary text no longer seems to be true. The installer no longer sets up /etc/fstab to mount using the filesystem's label in Beta 1.
Instead, for ext3/4 filesystems it uses the filesystem's random UUID that
was set automatically when it was formatted. Instead of LABEL= in the
/etc/fstab file, UUID= is used instead. I assume that the reason for this change has to do with SANs where systems might see multiple shared block devices on the SAN that happen to have the same filesystem label.

In fact, the installer no longer seems to set the filesystem label at all.

The blkid command will display the UUID for the filesystem, and normally users shouldn't have cause to change this.

Details of the problem:

Text currently READS:

16.2.3. Labeling the Partition
Next, give the partition a label. For example, if the new partition is
/dev/sda6 and you want to label it /work:

e2label /dev/sda6 /work

By default, the installation program uses the mount point of the partition
as the label to make sure the label is unique. You can use any label you
want.

I think that you may want to change this discussion to use the filesystem's built-in UUID instead to mirror the installer practice. I'd say for this you'd remove 16.2.3 entirely and rewrite 16.2.5 to find the UUID with 'blkid /dev/sda6' and then use it in the /etc/fstab file instead of the ext4 label.

If you keep the label approach, I suggest this SHOULD READ:

16.2.3 Labeling the Filesystem
Next, give the filesystem on the partition a label. For example, if
the filesystem is on the partition /dev/sda6, and you want to label it
/work:

e2label /dev/sda6 /work

Version-Release number of selected component (if applicable):
Text located at:

http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6-Beta/html/Storage_Administration_Guide/s3-disk-storage-parted-create-part-e2label.html

Comment 2 RHEL Program Management 2010-06-07 16:12:45 UTC

This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux major release.  Product Management has requested further
review of this request by Red Hat Engineering, for potential inclusion in a Red
Hat Enterprise Linux Major release.  This request is not yet committed for
inclusion.

Comment 5 Michael Doyle 2010-06-22 04:21:00 UTC

http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/s3-disk-storage-parted-create-part-mkfs.html

Verified in Red_Hat_Enterprise_Linux-Storage_Administration_Guide-6-en-US-0-5

http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/s3-disk-storage-parted-create-part-fstab.html

Still contains terminology about "partition" when it should be "file system".

The following is just one example.

The first column should contain LABEL= followed by the label you gave the partition.

Should be

The first column should contain LABEL= followed by the label you gave the file system.

Suggest all instances in the section should be "file system".

Also, was there a reason continuing to use LABEL= instead of UUID= as per Steve's comment?

Comment 6 Don Domingo 2010-07-14 00:02:46 UTC

(In reply to comment #5)
<snip>
> http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/s3-disk-storage-parted-create-part-fstab.html
> 
> Still contains terminology about "partition" when it should be "file system".
> 
> The following is just one example.
> 
> The first column should contain LABEL= followed by the label you gave the
> partition.
> 
> Should be
> 
> The first column should contain LABEL= followed by the label you gave the file
> system.
> 

corrected this:
http://brisvegas.bne.redhat.com/rhel6-storageguide/s3-disk-storage-parted-create-part-fstab.html

along with:
http://brisvegas.bne.redhat.com/rhel6-storageguide/s2-disk-storage-parted-create-part.html#s3-disk-storage-parted-create-part-mkpart

was:
After creating the partition, use the print command to confirm that it is in the partition table with the correct partition type, file system type, and size. Also remember the minor number of the new partition so that you can label it.

now:
After creating the partition, use the print command to confirm that it is in the partition table with the correct partition type, file system type, and size. Also remember the minor number of the new partition so that you can label any file systems on it.

> Suggest all instances in the section should be "file system".
> 
> Also, was there a reason continuing to use LABEL= instead of UUID= as per
> Steve's comment?    

i thought Steve meant i could keep the label approach as long as i applied his edits. anyhow, edited:
http://brisvegas.bne.redhat.com/rhel6-storageguide/s3-disk-storage-parted-create-part-fstab.html

Comment 11 Andrew Ross 2010-08-03 21:37:04 UTC

Verified: Red_Hat_Enterprise_Linux-Storage_Administration_Guide-6-web-en-US-0-13.el5

incl. comment#8 "you can label any file systems"

Comment 12 releng-rhel@redhat.com 2010-11-11 15:36:26 UTC

Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.