Bug 2142151 - Documentation for preparing local storage is not clear enough and could lead to data loss if followed.
Summary: Documentation for preparing local storage is not clear enough and could lead ...
Keywords:
Status: CLOSED DEFERRED
Alias: None
Product: Red Hat Enterprise Virtualization Manager
Classification: Red Hat
Component: Documentation
Version: 4.5.0
Hardware: Unspecified
OS: Unspecified
medium
low
Target Milestone: ---
: ---
Assignee: rhev-docs@redhat.com
QA Contact: rhev-docs@redhat.com
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2022-11-11 19:48 UTC by Sean Haselden
Modified: 2023-08-14 01:58 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
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Last Closed: 2023-08-14 01:58:25 UTC
oVirt Team: Storage
Target Upstream Version:
Embargoed:


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Red Hat Issue Tracker RHV-48032 0 None None None 2022-11-11 19:51:23 UTC

Description Sean Haselden 2022-11-11 19:48:24 UTC
Description of problem:

Documentation for preparing local storage states:
"On Red Hat Virtualization Host (RHVH), local storage should always be defined on a file system that is separate from / (root). Use a separate logical volume or disk, to prevent possible loss of data during upgrades.
"
https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.4/html/administration_guide/chap-storage#sect-Preparing_and_Adding_Local_Storage

In order to ensure a customer can correctly upgrade or reinstall, it should be made clear that the local storage filesystem should be on a separate volume group on a separate physical disk.  The current wording is ambiguous enough that I've seen a customer recently set up system incorrectly and overwrite their storage even though they did follow: 


"Create the local storage on a logical volume:" <--- this part should be explicit that it should be a new volume group or a partition on a disk that is not part of the base RHVH volume group.


Later in our documentation on doing an upgrade we point out to "not select the device(s) storing the virtual machines", which is correct as they should be on a separate device from the base RHVH volume. 

https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.4/html-single/upgrade_guide/index#Upgrading_hypervisor_preserving_local_storage_4-3_local_db
"When selecting the device on which to install RHVH from the Installation Destination screen, do not select the device(s) storing the virtual machines. Only select the device where the operating system should be installed."


We had a customer put 3 disks into one "rhvh" volume, which is how the above documentation could be interpreted. It might be worth changing this part as well:
# mkdir /data
# lvcreate -L $SIZE rhvh -n data
# mkfs.ext4 /dev/mapper/rhvh-data
# echo "/dev/mapper/rhvh-data /data ext4 defaults,discard 1 2" >> /etc/fstab
# mount /data


using 'rhvh' as an example could be confusing as the default install already creates a 'rhvh' volume group, and we want to ensure we do not use that volume group for /data purposes.

Comment 1 Casper (RHV QE bot) 2022-11-11 20:00:39 UTC
This bug has low overall severity and is not going to be further verified by QE. If you believe special care is required, feel free to properly align relevant severity, flags and keywords to raise PM_Score or use one of the Bumps ('PrioBumpField', 'PrioBumpGSS', 'PrioBumpPM', 'PrioBumpQA') in Keywords to raise it's PM_Score above verification threashold (1000).

Comment 2 ctomasko 2023-08-14 01:58:25 UTC
Closing. RHV nearing end of support. If you feel strongly that documentation must be updated, please reopen this issue.


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