Carbonite Server Backup
Linux Agent (32-bit) 8.90.1020
Release Notes, February 10, 2021
1 Overview
1.1  Release History
1.2  Compatibility
1.3  Supported Platforms
2 NEW FEATURES
3 INSTALLATION NOTES
3.1  Installation Requirements
3.2  Bare Metal Restore Requirements
3.3  Licensing
3.4  Install
3.5  Upgrade
4 FIXES and KNOWN ISSUES
4.1  Fixes
4.2  Known Issues
5 PRODUCT SUPPORT
5.1  Technical Support
5.2  Product Updates
5.3  Documentation

© Carbonite Inc. 2021. All Rights Reserved.
The release notes are governed by the Terms of Service found at https://www.carbonite.com/terms-of-use/carbonite-general-enterprise-terms-of-service. Carbonite, at its sole discretion, reserves the right to modify or revoke these Release Notes at any time, without notice.
1 Overview
The 32-bit Linux Agent is installed on each 32-bit Linux computer that you want to protect. Using Portal, you can manage the agent, back up data to a vault, and restore data from the vault. A plug-in for protecting Oracle databases on Linux is also available.
1.1  Release History 
Version 8.90.1020, February 10, 2021
1.2  Compatibility
Portal	To manage this Linux Agent version, we recommend using Portal version 8.88 or later.
Important: This agent version checks the public key of the Portal certificate when it tries to connect to Portal. If users are hosting their own Portal, we recommend updating the Portal certificate before new agents are registered to Portal or existing agents are upgraded from a version earlier than 8.63.	
Windows CentralControl	To take advantage of new features and important security enhancements, we highly recommend using Portal to manage the Linux Agent. 
If you must manage the Linux Agent using Windows CentralControl 8.90, please contact Support. 
Note: You cannot create Linux Bare Metal Restore jobs using Windows CentralControl. 
Important: Changing job configurations using Portal and Windows CentralControl alternately is not supported. Do not manage the same agent using both Portal and Windows CentralControl. 	
Director	This Linux Agent version is supported with Director version 8.50 or later. This agent version is also supported with Director version 8.4, but we strongly recommend the latest Director version so you can take advantage of the latest bug fixes and performance improvements.	
1.3  Supported Platforms
The Agent is supported on the following 32-bit Linux platforms:
•	CentOS 6 (up to Update 10) 1
•	Debian 8 (up to Update 11)
•	Oracle Linux 6 (up to Update 10) 1
•	Red Hat Enterprise Linux Server 6 (up to Update 10) 1
•	Ubuntu 14.04
1 The Agent requires GCC runtime libraries that usually must be downloaded and compiled manually on this platform. See Installation Requirements.	
The Agent is supported with the following Linux file systems: ext2, ext3, ext4, XFS, GFS, ReiserFS, and JFS.
The BTRFS file system is not supported.
2 NEW FEATURES
Bare Metal Restore backups for 32-bit systems
The 32-bit Linux Agent can now create Bare Metal Restore (BMR) backups of 32-bit systems. Previously, BMR backups were only supported for 64-bit systems with Linux Agent 8.83.
A Linux BMR backup includes an .iso file for starting the destination system and running the restore, and a backup in the vault that includes all data on the system, by default.
To create Linux BMR backups, Relax-and-Recover version 2.6 must be installed on the Linux system before you install the Agent. See https://relax-and-recover.org.
Note: You can create Linux BMR backups when you manage the agent using Portal. You cannot create Linux BMR backups using Windows CentralControl.
Support for upcoming new features 
This Linux Agent version includes support for new features that will be provided with an upcoming Director release. Information about these features will be added to the Agent documentation when the required Director version is available.
Aggressively-scheduled backups skipped
The Linux Agent now skips some backups with overly aggressive schedules. This gives the vault more time to run maintenance operations on the backup data and reduces schedule overloads.
If a backup job is scheduled to run more than once daily by one schedule and a backup is already running for the job, the agent skips the incoming backup. In previous agent versions, if a backup was running for the job, the incoming backup was queued and started when the current backup finished.
Note: Intra-daily backups, where backup jobs are scheduled to run more than once each day, are not currently supported with Server Backup. 
Security enhancements
Security enhancements have been added in this Linux Agent version.
3 INSTALLATION NOTES
3.1  Installation Requirements
•	CPU: 32-bit x86 or compatible processor (No support for Itanium processors.)
Note: Meet or exceed the hardware requirements of your operating system. 
•	RAM: Minimum of 2 GB
•	Disk space: The Agent requires at least 100 MB of free space for a new (fresh) installation. An upgrade may require more free space. If there is not enough disk space, the system will issue a message.
•	SELinux must be disabled on the system.
•	GCC runtime libraries: GLIBCXX 3.4.18 and GLIBCXX 3.4.19 or later.
Note:   On some 32-bit Linux platforms (e.g., CentOS 6, Oracle Linux Server 6, RHEL 6), the required GCC runtime libraries must be downloaded and re-compiled manually.
Note: You may see core dumps related to semaphore limits on the system. You can change the semaphore limits through the following kernel configuration parameters: 
Parameter /  Recommended Minimum Limit
semmni    /  128
Defines the number of semaphore identifiers in the kernel. 
This is the maximum number of unique semaphore sets that can be active at any one time. 
semmns    /  32000
Defines the maximum number of semaphores in the system. User processes include jobbed processes, plus all other semaphores required by other software. 
semmsl    /  250
Defines the maximum number of semaphores per identifier list. 
semopm    /  100
Controls the number of semaphore operations that can be performed per semop system call. 
3.2  Bare Metal Restore Requirements
To enable BMR backups, Relax-and-Recover version 2.6 must be installed on the Linux system before you install the Agent. For more information, see the Linux Agent and Oracle Plug-in User Guide. 
When you first run a BMR backup job, we recommend reserving a minimum of 1 GB of space in the root file system for the resulting .iso file.
When restoring a Linux server from a BMR backup, the destination machine must have:
•	At least 4 GB of RAM.
•	The same boot type (BIOS or UEFI) as the source system, and compatible hardware.
•	Hard drives should be the same size or larger than drives on the source system.
•	A connection to the network, so that it can communicate with the vault.
3.3  Licensing
Agent and Plug-in licenses are distributed automatically when the Agent connects to a vault (based on your license quota). To back up and restore data to or from a vault, you need a valid account, username and password. Contact your service provider to obtain the required information.
3.4  Install
The file name of the 32-bit Agent installation kit is: Agent-Linux-8.90.1020.tar.gz
Note:   You can only install the 32-bit Linux Agent on a 32-bit system. You cannot install the 32-bit Linux Agent on a 64-bit system.
The Agent kit installs the following binary files:
Binary File 	md5sum Value	
AgtUpgd 	5120edfab4bc83128f5c8d4d77d51626	
bmragent	eb13b724305504f72742e10e213b2588	
buagent 	19ceb85ec840ac54d8cf3ec172bd01fc	
libbase64.so	804b3cdfce8436f1efb86708e8e00caf	
libcatalog_protobuf.so	37acb59cd8f3fdb78c490f718b922375	
libcrypto.so.1.0.0	1db0cbb79394960e39c1e0e211ff1ac3	
libevccl.so	1acd9448a23e8f443a374711c96f0c8a	
libevclient.so	6c76f0e15dafebdd48f90089fbe6e0c9	
libevplugins.so	1f08b1bc625f46987456d436dcc566c9	
libevtrace.so	7a77d843703d2888acceef73c2198f85	
liblz4.so.1.3.0	c58cc4d36ebfb17cd492e33e378eb2e5	
libprotobuf.so.15.0.1	190237bb8636831df282d2e39b3dee84	
libssl.so.1.0.0	85b0e1f0347292c7db55dd45ade1eb8b	
libstdsoap2.so.2.8	f6f067275cb8b74ee5ab85d1fa2da611	
VV	58e696deb680065fcbc757b7c0dc4e6c	
VVAgent	35c1568e0640a3a34f8125b13ee3decc	
xlogcat 	46f800b401567d1a20f9a34f89d76d33	
To obtain md5sum values, issue the following commands. These commands are examples based on an Agent that has been installed in the default location (i.e., /opt/BUAgent).
 cd /opt/BUAgent
 md5sum *
3.5  Upgrade
You can upgrade the following Linux Agent versions to version 8.90:
•	Version 8.6x
•	Version 8.50
•	Version 8.1x
•	Version 8.00
•	Version 7.50
•	Version 7.2x
To upgrade a previous Linux Agent version to version 8.90, first upgrade the Agent to version 7.2x.
4 FIXES and KNOWN ISSUES
4.1  Fixes
•	In a delta backup after a job's delta (.dta) file has been recreated, the Agent now correctly detects when a file's extended attributes have changed. The associated task on the vault is not marked as suspect. (EV-48527, EV-46287)
•	Backups no longer fail because the Agent configuration file gets overwritten. (EV-38678)
•	If the Agent loses connection to the vault during a backup, the Agent now waits longer to reconnect to the vault and continue the backup. (EV-41322, EV-34740)
4.2  Known Issues
•	Scheduled custom commands are not supported with this agent version. (EV-31488)
•	If a job is seeded to a vault using Agent version 7.34 or earlier and reseeded using Agent version 7.50 or later, the vault storage size for the job data cannot be reduced. (EV-25740)
•	When you re-register an Agent with a vault, backup jobs that never ran may not be brought to the Agent. The jobs still exist on the vault, so you cannot create jobs with the same names.
WORKAROUND: After an Agent re-registration, delete jobs with no safesets from the vault before creating jobs with the same names. (EV-13227)
•	When only permissions have changed in a file in the ReiserFS file system, permissions are backed up successfully but the deltized size may appear as 0 bytes in the Backup Summary report. (EV-13683)
•	When a backup is run from the Linux Bash shell, it may end with the following message: User defined signal 2 
WORKAROUND: Trap the signal, which is used to terminate running threads, by beginning the backup script with the following line: trap " USR2 
•	If your backup selection contains hardlinks outside of your selection, you may receive a backup log warning indicating that some hard links related to these file(s) were not selected and have not been backed up. This may occur even if you exclude these hardlink files. To avoid this warning, include all the hardlink files sharing the same inode. (19795)
•	When you perform a complete system restore (DR), make sure that there is sufficient disk space for the creation of large recovery logs from the Agent (and other possible logging or auditing from the operating system). File-level logging on a setup containing a large file system can generate a large log, which may fill up the available or allocated disk space. If the logs are on the same partition as the root file system, this may prevent the OS from booting. (19353)
•	An NFS backup job for a mounted file system may fail if the NFS mount is disconnected at run time. The error messages for this failure may not explain that the problem is related to NFS. (19215)
•	When you restore a very large number of files to an alternate location, you may run out of inodes for the file system. This may stop the restore process from responding. If you kill the VV process, defunct processes may remain and truncated restore logs may result. The logs may indicate that there is no space left on the device, but this may not be true. Because each file consumes an inode, you may not be able to restore additional files (regardless of how much space is available).
Recommendation: Allocate more inodes for the destination file system. (18967)
•	The command-line log viewer, xlogcat, uses the default language that you select during installation unless the LANG environment variable indicates a different supported language. For example, if German (de-DE) is your selected language, but your LANG value specifies U.S. English (LANG=en_US.utf8), xlogcat may display the log in English. You can override this using the "-l" (lowercase L) command-line parameter, or by adjusting the LANG variable. (18941)
•	For a backup or restore task on an NFS system to succeed, you need permissions to read, write and create files and directories on the mounted Network File System. This includes the remote system allowing operations for an anonymous user. A good test is to try it from the command line first. If you cannot read/write/create files or directories on NFS manually, the Agent backup and restore may not work. This issue applies to all Linux platforms.
•	Linux systems may be configured with strong firewall settings (IP tables) that may block communication between the Agent and Portal or Windows CentralControl.
The following ports are used by default for the Agent:
  * 808, 8031 (inbound) - VVAgent control by Windows CentralControl
  * 8086, 8087 (outbound) - buagent registration and control by Portal
  * 25 (outbound) - email notification
  * 2546 (outbound) - VV backup, restore, and synchronization with the Director (Vault)
To allow management of the Agent by Windows CentralControl, you may open the firewall with a rule similar to this:
iptables --append <chain-name> -p tcp -m tcp --dport 808 --syn -j ACCEPT
This rule may be made permanent in the normal way for your distribution.
•	Certain file systems and directories may be excluded from backups, including the /dev (device) directory (including the devpts file system at /dev/pts), /boot directory, /var/run directory, and the proc file system (usually at /proc). In Linux kernel version 2.6, the sysfs file system may represent the system hardware devices and drivers (usually at /sys). This may also be excluded from backups. 
Note: On a complete system backup, /dev and /proc directories are not backed up.
The Linux Agent only protects these locations under their default names.
These files must be restored to an alternative location and replaced manually if necessary, as automatic replacement may leave the operating system in an unusable state.
•	When restoring Linux system files, the boot loader should be reconfigured to find the restored operating system files and kernel in their current positions on the hard drive. When using GNU GRUB (http://www.gnu.org/software/grub/), follow the instructions from the GRUB user manual for installing GRUB natively: http://www.gnu.org/software/grub/manual/grub.html#Installation. For other boot loaders, refer to the manual provided by your vendor.
•	By default, chkconfig may not include VVAgent in the list of services that it manages. If you add VVAgent to chkconfig, the default run levels become 3 and 5. 
Recommendation: Use 3 and 5 as default run levels for starting the VVAgent script. (8321)
5 PRODUCT SUPPORT
5.1  Technical Support
Contact information for your provider is available through the Need Help button in Portal.
5.2  Product Updates
Product updates are available through your provider.
5.3  Documentation
The following documentation is available for Agent for Linux (32-bit):
•	Server Backup online help (https://onlinehelp.evault.com) and knowledge base (http://support.carbonite.com/evault)
•	Release notes (this document)
•	User Guide