Data Archiving on Jabba

About our data archiving system Jabba

All data you put on our data archiving system will we stored on tape drives. Like this the archive system can hold a large amount of data. The downside is that read and write operations are slow since the tape roboter has to physically grab the right tapes to handle your data. Thus, you should not use Jabba for data you use daily. But if you have a huge amount of simulation data that you might need in some weeks, Jabba would be a good place to take care of them.

Jabba Usage

Access rights

We will have to give the proper rights to your account before you will be able to use Jabba. Please write an email to support@ee.ethz.ch if you need access to our data archiving system.

How to access Jabba

As soon as access is granted, you have the following options to get/put data from/to the archiving system:

• NFS (preferred on Linux): /usr/jabba/archive/INSTITUTE/USERNAME or /usr/jabba/backup/INSTITUTE/USERNAME

• Samba: \\jabba\USERNAME

• OpenSSH: scp

Important notes

Please follow these rules when storing data on Jabba:

• Only write big archive files (.tar.gz, .zip, ...) to jabba, not many small files.

• The ideal size of these archive files is between 5 and 10 Gigabytes.
• Don't create archive files bigger than 10 Gigabytes.
• Take care when you delete files. You are working on the backup system and there is no further backup of these data.

• Only put data into the archive or backup folder.

If you don't obey these rules, backing up and restoring your data will take very, very long.

Differences between storage areas

• archive : Files within the archive directory will be stored on two tapes, five minutes after the last modification.

• backup : Files within the backup directory will be saved to one tape, 30 minutes after their last modification on harddisk.

In both cases the cached files on harddisk will be deleted after storage on tape only if the threshold of free disk space on the partition is reached.

Some usage examples

• Backup Pictures folder via NFS:

   tar cfv - Pictures | /usr/isgtc/bin/tubasplit --size 5056 /usr/jabba/backup/tik/hans/Pictures.tar

• Archive Pictures folder with ssh:

   tar cfv - Pictures | ssh jabba "/usr/isgtc/bin/tubasplit --size 5056  /usr/jabba/archive/tik/hans/Pictures.tar

  Note: The usage through NFS/Samba is preferred since above command creates excessive CPU load on the archive system.

• Get two tar archives via NFS and unpack them in scratch:

   cd /scratch/hans
   cat  /usr/archive/biwi/hans/Pictures_1.tar /usr/archive/biwi/hans/Pictures_2.tar | tar xvf -

Advanced usage

The data transfer between harddisk and tape storage can be influenced with the commands below. You have to be logged in on jabbe through SSH to use these commands. Please consult the man pages for further details.

• Command	Description
  sls	An extended version of GNU ls for listing directory information
  sdu	An extended version of GNU du
  archive	Set archive attributes and archive files
  release	Release disk space and set release attributes
  stage	Set staging attributes and copy off-line files to harddisk
  ssum	Set file checksum attributes