Storix Software SBAdmin TSM Edition Users Guide - Manual (Page 38)

Storix System Backup Administrator 38 Version 8.2 TSM Edition User Guide
Wednesday Level 2
Thursday Level 3
Friday Level 4
a. On Monday, the entire system will be backed up. Note, however, that only the volume groups
indicated in the backup profile will be included, if applicable.
b. On Tuesday, only the files that have changed since Monday’s backup will be included in the
incremental level 1 backup.
c. On Wednesday, only files backed up since the last prior-level backup (level 1) will be included in
this backup.
d. Likewise on Thursday and Friday.
e. On the following Monday, a new incremental level 0 is performed, backing up all data once again.
This is the new backup from which all subsequent backups will be based. Any incremental backups
performed prior to this level 0 will be considered obsolete.
2. In a second example, consider the following backup schedule, which is often referred to as differential
backups since we’re effectively backing up the differences between the system as it is now versus a
specific day in the past :
First day of the Month Level 0
Each Friday night
Level 4
Each other weekday Level 7
a. On the first day of every month, regardless of the day of the week, a full incremental backup is
performed.
b. The next day, an incremental level 4 will be performed (if Friday) or an incremental level 7 will be
performed (if Monday through Thursday)
In this example, keep in mind that it is not necessary to perform a level 1 backup after a level 0, since
each level (1-9) will backup the data from the last prior-level backup performed, even if it was several
levels prior. Therefore, if your last level was 0 (full), then either a level 4 or a level 7 will backup the
same data. However, if your last level was 4, a level 7 will always backup files changed only since the
last level 4.
In addition, each weekday the same backup level will be performed. Since all data will be backed up
since the last prior level, your previous day’s backup of the same level will become obsolete.
3. This example is a differential backup, where all backups are based on the most recent level 0 (full)
backup that was performed:
Every Friday night Level 0
Monday through Thursday night Level 1
a. Every Friday night, a full backup level 0) is performed.
b. On every other night, a level 1 backup is performed. The result is that, each day, all files that have
been created or changed since the Friday night backup will be backed up again. The size of the
backup will grow each day until after the next Friday night backup is again performed.
Restoring from Incremental Backups
If re-installing the system from the backup, you must always restore from a level 0 incremental backup (or
one that did not use an incremental level). The system installation process will not allow you to select an