Posts Tagged ‘Backup Exec’

Disk to Disk to Tape backup in Backup Exec

July 14, 2012

Notice: It seems that D2D2T feature in Backup Exec 11d is buggy. D2D2T duplicate jobs (which transfer data from disk to tape) are insanely slow and nobody has yet solved this problem. You can try to implement backup of raw Backup to Disk Folder, but it is associated with number of  difficulties when restoring. Files from Backup to Disk Folders are media and they conflict with media which is currently used for backup.

Typical backup solution in most organizations consists of backup server and tape drive/autoloader/tape library connected directly to backup server. Every night backups are pushed to tape through backup server. But sometimes it is more complicated. We have NetApp filer with StorageTek tape library connected to the filer. Backup server sends NDMP commands to the filer and filer in its turn performs actual data transfer to tapes from disk shelves. Most of our hosts are VMware virtual machines. We backup whole .vmdk files, but we also want to perform file-level backups from some of virtual machines. To accomplish that we set up backup agents on all virtual machines, but we can’t backup files directly to tapes, because they do not originate from NetApp filer volumes. So we decided to implement D2D2T multistage backup. The idea here is to create a CIFS share on the filer, backup data there and then transfer data from CIFS share to tapes.

First step here is to configure disk to disk backup. Backup Exec stores disk to disk backups in binary files. Folder where files are stored is listed on Devices tab and files are listed on Media tab. Initially, you need to create a Backup to Disk Folder in Devices tab. There you choose size for backup-to-disk files and maximum number of backups per backup-to-disk file. If backup is larger than file size, it is splitted in several files. If file size is smaller than backup, several backups will be written to one file. I use defaults with 16GB file size. Then you create backup jobs as usual (by configuring selection list and policy) using Backup to Disk Folder as target device.

As a second step you need to instruct Backup Exec to transfer backed up files to tape, upon disk to disk job completion. Backup Exec has “duplicate jobs” to implement that. Go to your backup policy properties, click “New Template”, choose “Duplicate Backup Sets Template”, pick template for which you want to create duplicate, in “Devices and Media” choose your tape library, in “Schedule” choose “Run only according to rules for this template”. This will create duplicate template and rule which will start duplicate job after main job completes. As a result you will have duplicate data on disk and on tape.

Disconnect stalled NDMP sessions

March 30, 2012

Once, I started installation of Symantec Backup Exec service pack update when tape library inventory job was running. After installation has been completed I ended up with library offline and not available. It happened because of hanged NDMP sessions. To list your media changer and tape drives information run:

storage show mc
storage show tape

or

sysconfig -m
sysconfig -t

To list and kill particular NDMP sessions run:

ndmpd status
ndmpd kill job_id

Then restart Backup Exec service.

GFS backup scheme in Symantec Backup Exec

March 23, 2012

Grandfather-Father-Son is an industry standard backup scheme, where you have 5 daily backups, 5 weekly backups and as many monthly as you need. Symantec Backup Exec has prebuilt policy for GFS, but before going into configuring backup scheme itself, lets talk a little bit about general backup job configuration in Backup Exec.

Basic Terminology

Inside user interface you see Jobs, Policies, Selection Lists and Media Sets. First of all you need to create Selection List, which describes what you want to backup. There you select files and folders from your Windows, Unix or NDMP servers. Then you create Media Set, which is a collection of tapes with particular append and retention periods. Append period specifies how long data can be added to the same tape and retention period tells for how long data cannot be overwritten. Retention period starts form the time of last append to the tape. Then you create Policy. Policy, by means of templates, defines when backup jobs are run, where backups are stored and what is the type of backup – incremental, differential or full. One policy can consist of several templates. In template you specify backup date and time, as well as target tape library.

GFS Implementation

Backup Exec has a template for GFS backup rotation scheme. Click “New policy using wizard”, choose GFS scheme and then select schedule, target backup device and media sets for daily, weekly and monthly backups. By default Backup Exec suggests the following configuration.

Three tape media sets:

  • Daily Media Set – 1 week overwrite, 1 week append
  • Weekly Media Set – 5 weeks overwrite, 5 weeks append
  • Monthly Media Set – 1 year overwrite, 1 year append

Policy with three templates:

  • Daily Backup – Monday to Friday, Incremental
  • Weekly Backup – every Friday, Full
  • Monthly Backup – first Saturday of each month, Full

Also Backup Exec automatically creates rules to resolve conflicts. For example when both Daily and Weekly backups try to run on Friday, jobs do not conflict, because weekly backups always supersede daily. Same for monthly.

I personally prefer another schedule. First of all, if you run your jobs after midnight, you will need to shift your schedules from Mon – Fri to Tue – Sat. Additionally, I run monthly backup on the first Saturday of the month. Backup Exec by default (taking into consideration my one day shift) would suggest first Sunday for the monthly backup. However, it doesn’t make much sense to have weekly on Saturday and then monthly next day on Sunday. You would just consume more space without any benefit. Also, you can schedule monthly on the last Saturday of the month, but if the last day is Thursday, for example, then you will loose four business days from your monthly backup.

After the policy is created, you need to create backup jobs using this policy by clicking on New jobs using policy. All three jobs will be created automatically according to Selection List, as well as Policy Schedule, Target, and Backup Type parameters.

I’d also recommend everyone to configure notifications. There are general Alerts properties as well as inside each job.

Why I wouldn’t recommend Microsoft Data Protection Manager as a backup solution

February 22, 2012

When taking into account different backup solutions which are in the market, MS DPM 2010 was rather attractive for us. It’s a solution from leading software vendor and it’s cheap. However, DPM has a number of limitations which forced us to abandon it and rebuild our backup procedures from ground up. Here I’d like to describe major points as impartial as I can.

The first thing about DPM is that it uses VSS snapshots as one and only backup method. The major consequence is that you are very limited in flexibility and cannot do incremental, differential or full backups, implement GFS backup strategy or Progressive Paradigm. The only option you have is to exclude weekends or any other particular days from backups. That means ineffective storage utilization and inability to have longer data retention as you could have with flexible backup policy as GFS for instance, not to mention additional spendings on storage.

Another problem of VSS is that it supports only 64 snapshots. Basically, that means if you exclude weekends from your backup policy, you will be able to have backups for 89 day period. It’s clearly not enough if, for example, you work in a financial institution where you have strict policies of long data retention. DPM assumes that you will use tapes for prolonged data retention. If you already have tapes then you are good to go, if not then once again it’s additional expenditures.

Interestingly enough in DPM you cannot have different retention policies for data which resides on the same volume. Say I want to keep database backups for 3 months and transaction logs for the last week. If database backups and transaction logs reside on the same volume then you will have to create the second volume and separate them.

Limitation which I personally find very inconvenient is space reservation. Each time you create a Protection Group you reserve space for it. Say 500GB. And you cannot change it. In case one folder from ten, which you backup from the server, moves to another place and 250GB become free, the only option you have is to destroy Protection Group, loose all backups and recreate it. DPM helps you in situation when you don’t know how your data will grow and you can specify smaller storage size initially and it will automatically grow as needed. However, it can extend only 32 times. If you hit that limit, then you are in the same situation as before.

Another major issue arise when you change protected server name. If server name is changed the only option you have is destroying protection group, loosing all backups and recreating it.

The next limitation I also find inflexible is target storage. In DPM you can only use blocked devices as target storage to keep your backups. So it’s either DAS, FC or iSCSI storage. NAS is not supported.

If you work in SMB then you would probably have issues with installation and support of legacy systems. DPM works only on 64-bit Windows Server 2008 platforms (Windows Server 2003 is not supported). DPM doesn’t support Bare Metal Recovery (BMR) of Windows Server 2003.

And lastly, DPM keeps all data on a raw volume. Raw volumes are more efficient in terms of disk I/O performance. But when it’s helpful for DBMS it doesn’t seem to make any difference for backup software. The downside of it is higher risk of loosing all data in case of volume damage or DPM bug. It’s arguable, so I will leave it as my personal opinion.

In conclusion, it’s rather disappointing to see how software with 7 years history (DPM 2006 was released in 2005) has more limitations than any backup software solution I can think of. Even if you don’t have enough money for Symantec Backup Exec, ARCServe Backup, HP Data Protector or any other software, I would recommend to make more effort and search for some other solution. Otherwise you can fall into the same trap as we did.

Installing Symantec Backup Exec Agent for Linux

October 7, 2011

Symantec Backup Exec Linux/Unix agent is called RALUS which stands for Remote Agent for Linux and Unix Servers. I obtained my RALUS installation from official Symantec CDs. If you don’t have them you probably can download them from Symantec web site. Here is the sequence:

  1. Mount CD or iso image to your Linux host.
  2. Run ./installralus script and follow instructions. I use defaults. The only thing you should enter is Media Server IP address. Installation script add itself to rc*.d levels automatically.
  3. After installations is completed create backup user, add it to beoper group and set its password: # useradd backup -c “User for Symantec Backup Exec”;  # usermod -G beoper backup; # passwd backup.
  4. Start BE agent manually for the first time: # /etc/init.d/VRTSralus.init start

That’s it. Now you can see your server under Linux/Unix Servers section when creating backup job.

Add #1: If agent doesn’t start and you get an error with libstdc++.so.5 missing in /var/VRTSralus/beremote.service.log then install compat-libstdc++-33.

Add #2: If you have active firewall then you need to open additional ports. For me it was tcp 10000-10200. It’s 10000 plus port range you can find on media server in Tools->Options->Network and Security tab. For CentOS firewall rule would be:

-A RH-Firewall-1-INPUT -m tcp -p tcp -s media_server_ip –dport 10000:10200 -j ACCEPT

Add #3: In case you also write firewall rules to OUTPUT chain then open output tcp 10000:

-A RH-Firewall-1-OUTPUT -m tcp -p tcp -d media_server_ip –dport 10000 -j ACCEPT

If you don’t have RH-Firewall-1-OUTPUT add also:

:RH-Firewall-1-OUTPUT – [0:0]
-A OUTPUT -j RH-Firewall-1-OUTPUT

I leave possibility of me being wrong, but SBE documentation says:

Symantec recommends having port 10000 open and available on the Backup Exec media
server as well as on the remote systems.

Additional connections from the media server to the Remote Agent will be initiated on any available port.

I understand that as both agent and media server may connect to each other’s 10000 port and additional 10001:10200 connections are initiated from medias server.