Reverting to the Data ONTAP 6.4 release family

Issues you must resolve before reverting

The following sections discuss upgrade issues that you must resolve before upgrading to the Data ONTAP 6.4 release family:

Reversion with larger inodes

When you upgrade to Data ONTAP 6.5 or later, your storage system is upgraded to support larger inodes. There are two instances in which larger inodes can cause a reversion to an earlier release to fail:

While the inode upgrade is still in progress
When there is not enough disk space or there are not enough free inodes in a volume
Note
Reverting to an earlier release can take several hours, depending on the number of total inodes and inodes used on your system.

To determine whether an inode upgrade is still in progress, complete the following steps.

Step	Action
1	Enter the following command: priv set advanced Result The storage system prompt now displays an asterisk (*) after the storage system name to indicate that you are in advanced mode.
2	Enter the following command: wafl scan status Example If the upgrade is still in progress, the storage system displays a message similar to the following: Volume vol1: Scan id Type of scan progress 2 inofile upgrade 849387 of 33554472 Note If an `inofile upgrade` scan type is not displayed, the inode upgrade is done.

Step

Action

Enter the following command:

priv set advanced

Result

The storage system prompt now displays an asterisk (*) after the storage system name to indicate that you are in advanced mode.

Enter the following command:

wafl scan status

Example

If the upgrade is still in progress, the storage system displays a message similar to the following:

Volume vol1:

Scan id       Type of scan          progress

      2       inofile upgrade      849387 of 33554472

Note
If an inofile upgrade scan type is not displayed, the inode upgrade is done.

When more disk space or free inodes are needed for reverting, you see a message similar to the following:

Volume vol1: There are not enough free inodes to revert the ACLs 
with nlinks over 65535.

A minimum of ### inodes needed (maximum ###).

Minimum and maximum inodes needed depends on the number of hard links (nlinks) over 65,535.

You can free up inodes in a volume by deleting files or by moving files to a volume that has free inodes.

To view the number of used and free inodes, complete the following step.

Step	Action
1	At the storage system console, enter the following command: df -i

Excessive subdirectories and hard links

If you have more than 65,533 subdirectories or 65,535 hard links, you must move the extra subdirectories to another directory and delete the extra hard links before you revert. When too many hard links exist during a revert, you will see an error message similar to the following:

Scanning all inodes in volume "vol1" for non-ACL inodes with nlinks 
over 65535 0% done

inode 102, file has too high of an nlink (81519)

inode 101, file has too high of an nlink (90001)

0% done.

Large directories can be reverted but cannot be made larger

Data ONTAP 6.5 and later releases allow larger directories than in previous versions. If you have a directory larger than 65,535 KB, the directory will be accessible when you revert to an earlier version of Data ONTAP and will remain at its current size, but you cannot make it any larger.

Reverting entries in the /etc/exports file

When you upgrade to Data ONTAP 6.5 or later, new access rules are applied to the /etc/exports file. If you revert to an earlier version of Data ONTAP, the /etc/exports file will be scanned to determine whether it conforms to the earlier version's format. If not, the reversion will not proceed until the file has been fixed.

To fix the file, you can edit it manually or use the exportfs -d command to revert the file. Using exportfs -d will fix most of the revert issues. However, some changes to the /etc/exports file are not fixed with the exportfs -d command and cause a message to be sent to the console during a reversion. If any of these issues are not fixed, that line in the /etc/exports file does not load and access is denied for that resource. This happens in the following circumstances:

Lines greater than 4,096 characters, excluding comments
Entries exceeding 256 characters in either the -rw or -root options
Too many entries in the -access option
Attention
Data ONTAP has no way to determine whether entries in an access list represent a netgroup or a host name; therefore, no checking is done on names during reversion. If netgroups exist in the -rw and -root options, you must manually edit the file to conform to the earlier format; otherwise, the export line containing the netgroup does not load and access is denied for that resource.

For more information about the /etc/exports file, see the exports(5) man page.

RAID-related errors

Updates made to RAID in Data ONTAP 6.5 or later can sometimes cause problems when you revert to an earlier version, and the reversion may fail. The following is a list of possible problems and the resulting error messages that are sent to the console:

RAID reversion issue	Message with required action
RAID-DP volumes are present	There is a raid_dp volume present which cannot be reverted. Downgrade these volumes with `vol options <vol> raidtype raid 4'.
RAID label assimilation in progress	RAID label assimilation in progress. Wait for assimilation to complete before reverting.
Failed Disk Registry in process of being updated	Please wait one moment while RAID updates the Failed Disk Registry.
Sanitized disk present	There are sanitized disks present. Either remove them or issue a `disk sanitize release' to return sanitized disks to the spare pool.
Disk in process of being sanitized is present	There are sanitized disks present. Either wait for the sanitize to complete, or issue a `disk sanitize abort' to return sanitized disks to the spare pool.
Sparecore disk present	There is a sparecore disk present which cannot be reverted. Wait for the sparecore to complete before running revert.

Running a RAID label version that is too new

When you install a version of Data ONTAP earlier than 6.5, you might get a message that the RAID label version you are running is either invalid or too new. This can happen when the storage system contains disks that were previously upgraded with Data ONTAP 6.5 or later, and were not reverted using the revert_to command. In cases where a disk has not been properly reverted, the following actions occur:

The disk is not assimilated.
The disk is moved to the broken disk pool with "bad label" given as the reason.
An AutoSupport notice is sent to NetApp and the customer.

SnapLock volumes must be removed before reverting

Before reverting to a version of Data ONTAP earlier than 6.5, SnapLock volumes must be removed. For more information about SnapLock, see the Storage Management Guide.

Fractional reserve must be 100% before reverting

Fractional reserve (setting space reservation to less than 100 percent) is available in Data ONTAP 6.5.1 or later, but it is not available in the 6.4 release family. If you want to revert from Data ONTAP 6.5.1 or higher to a Data ONTAP 6.4 family release and you are using fractional reserve, you must make sure you have enough available space for 100 percent overwrite reserve. If you do not have enough space when you revert, Data ONTAP displays the following message:

You have an over committed volume. You are required to set the 
fractional_reserve to 100. This can be done by either disabling 
space reservations on all objects in the volume or making more 
space available for full reservations or deleting all the snapshots 
in the volume.

To avoid this problem when you revert to a Data ONTAP 6.4 family release, make sure that you have enough available space for 100 percent overwrite reserve. If you do not have enough space or you have received this message, make space by deleting snapshots.