This section provides sample backup schedules. All schedules assume you begin with a full backup (level 0), and that you use the -u option to record each backup.
The table below shows the most commonly used incremental backup schedule; it is recommended for most situations. With this schedule:
All files that have changed since the lower-level backup at the end of the previous week are saved each day.
For each weekday level 9 backup, the previous level 0 or level 5 is the closest backup at a lower level. Therefore, each weekday tape contains all the files changed since the end of the previous week (or the initial level 0 for the first week).
For each Friday level 5 backup, the nearest lower-level backup is the level 0 done at the beginning of the month. Therefore, each Friday's tape contains all the files changed during the month to that point.
Floating |
Mon |
Tues |
Wed |
Thurs |
Fri |
|
---|---|---|---|---|---|---|
1st of Month |
0 |
|
|
|
|
|
Week 1 |
9 |
9 |
9 |
9 |
5 |
|
Week 2 |
9 |
9 |
9 |
9 |
5 |
|
Week 3 |
9 |
9 |
9 |
9 |
5 |
|
Week 4 |
9 |
9 |
9 |
9 |
5 |
The table below shows how the contents of the tapes can change across two weeks using the previous schedule. Each letter represents a different file.
Table 42-8 Contents of Tapes for Daily/Weekly Cumulative Schedule
Mon |
Tues |
Wed |
Thurs |
Fri |
|
---|---|---|---|---|---|
Week 1 |
a b |
a b c |
a b c d |
a b c d e |
a b c d e f |
Week 2 |
g |
g h |
g h i |
g h i j |
a b c d e f g h i j k |
With this schedule, you need six tapes (if you want to reuse daily tapes), or nine tapes (if you want to use four different daily tapes): one for the level 0, four for the Fridays, and one or four daily tapes.
If you need to restore a complete file system, you will need the following tapes: the level 0, the most recent Friday tape, and the most recent daily tape since the last Friday tape (if any).
The table below shows a schedule where each weekday tape accumulates all files that changed since the beginning of the week (or the initial level 0 for the first week), and each Friday's tape contains all the files changed that week.
Table 42-9 Daily Cumulative/Weekly Incremental Backup Schedule
Floating |
Mon |
Tues |
Wed |
Thurs |
Fri |
|
---|---|---|---|---|---|---|
1st of Month |
0 |
|
|
|
|
|
Week 1 |
9 |
9 |
9 |
9 |
3 |
|
Week 2 |
9 |
9 |
9 |
9 |
4 |
|
Week 3 |
9 |
9 |
9 |
9 |
5 |
|
Week 4 |
9 |
9 |
9 |
9 |
6 |
The table below shows how the contents of the tapes can change across two weeks using the previous schedule. Each letter represents a different file.
Table 42-10 Contents of Tapes for Daily Cumulative/Weekly Incremental Backup Schedule
Mon |
Tues |
Wed |
Thurs |
Fri |
|
---|---|---|---|---|---|
Week 1 |
a b |
a b c |
a b c d |
a b c d e |
a b c d e f |
Week 2 |
g |
g h |
g h i |
g h i j |
g h i j k |
With this schedule, you need six tapes (if you want to reuse daily tapes), or nine tapes (if you want to use four different daily tapes): one for the level 0, four for the Fridays, and one or four daily tapes.
If you need to restore a complete file system, you need the following tapes: the level 0, all the Friday tapes, and the most recent daily tape since the last Friday tape (if any).
The table below shows a schedule where each weekday tape contains only the files changed since the previous day, and each Friday's tape contains all files changed since the initial level 0 at the beginning of the month.
Table 42-11 Daily Incremental/Weekly Cumulative Backup Schedule
Floating |
Mon |
Tues |
Wed |
Thurs |
Fri |
|
---|---|---|---|---|---|---|
1st of Month |
0 |
|
|
|
|
|
Week 1 |
3 |
4 |
5 |
6 |
2 |
|
Week 2 |
3 |
4 |
5 |
6 |
2 |
|
Week 3 |
3 |
4 |
5 |
6 |
2 |
|
Week 4 |
3 |
4 |
5 |
6 |
2 |
The table below shows how the contents of the tapes can change across two weeks using the previous schedule. Each letter represents a different file.
Table 42-12 Contents of Tapes for Daily/Weekly Cumulative Backup Schedule
Mon |
Tues |
Wed |
Thurs |
Fri |
|
---|---|---|---|---|---|
Week 1 |
a b |
c d |
e f g |
hi |
a b c d e f g h i |
Week 2 |
j k l |
m |
n o |
p q |
a b c d e f g h i j k l m n o p q r s |
With this schedule you need at least nine tapes (if you want to reuse daily tapes--not recommended), or 21 tapes (if you save weekly tapes for a month): one for the level 0, four for the Fridays, and four or 16 daily tapes.
If you need to restore the complete file system, you need the following tapes: the level 0, the most recent Friday tape, and all the daily tapes since the last Friday tape (if any).
The table below shows an example backup strategy for a heavily used file server on a small network where users are doing file-intensive work, such as program development or document production. It assumes that the backup period begins on a Sunday and consists of four seven-day weeks.
Table 42-13 Schedule of Backups for a Server Example
Directory |
Date |
Level |
Tape Name |
---|---|---|---|
root (/) |
1st Sunday |
0 |
n tapes |
/usr |
1st Sunday |
0 |
" |
/export |
1st Sunday |
0 |
" |
/export/home |
1st Sunday |
0 |
" |
|
1st Monday |
9 |
A |
|
1st Tuesday |
9 |
B |
|
1st Wednesday |
5 |
C |
|
1st Thursday |
9 |
D |
|
1st Friday |
9 |
E |
|
1st Saturday |
5 |
F |
root (/) |
2nd Sunday |
0 |
n tapes |
/usr |
2nd Sunday |
0 |
" |
/export |
2nd Sunday |
0 |
" |
/export/home |
2nd Sunday |
0 |
" |
|
2nd Monday |
9 |
G |
|
2nd Tuesday |
9 |
H |
|
2nd Wednesday |
5 |
I |
|
2nd Thursday |
9 |
J |
|
2nd Friday |
9 |
K |
|
2nd Saturday |
5 |
L |
root (/) |
3rd Sunday |
0 |
n tapes |
/usr |
3rd Sunday |
0 |
" |
/export |
3rd Sunday |
0 |
" |
/export/home |
3rd Sunday |
0 |
" |
|
3rd Monday |
9 |
M |
|
3rd Tuesday |
9 |
N |
|
3rd Wednesday |
5 |
O |
|
3rd Thursday |
9 |
P |
|
3rd Friday |
9 |
Q |
|
3rd Saturday |
5 |
R |
root (/) |
4th Sunday |
0 |
n tapes |
/usr |
4th Sunday |
0 |
" |
/export |
4th Sunday |
0 |
" |
/export/home |
4th Sunday |
0 |
" |
|
4th Monday |
9 |
S |
|
4th Tuesday |
9 |
T |
|
4th Wednesday |
5 |
U |
|
4th Thursday |
9 |
V |
|
4th Friday |
9 |
W |
|
4th Saturday |
5 |
X |
With this plan, you use 4n tapes (the number of tapes needed for four full backups of root (/), /usr, /export, and /export/home), plus 24 additional tapes for the incremental backups of /export/home. This plan assumes that each incremental backup uses one tape and you save the tapes for a month.
Here's how this plan works:
On each Sunday, do a full backup (level 0) of root (/), /usr, /export, and /export/home. Save the level 0 tapes for at least 3 months.
On the first Monday of the month, use tape A to do a level 9 backup of /export/home. ufsdump copies all files changed since the previous lower-level backup (in this case, the level 0 backup that you did on Sunday).
On the first Tuesday of the month, use tape B to do a level 9 backup of /export/home. Again, ufsdump copies all files changed since the last lower-level backup--Sunday's level 0 backup.
On the first Wednesday, use tape C to do a level 5 backup. ufsdump copies all files changed since Sunday.
Do the Thursday and Friday level 9 backups on tapes D and E. ufsdump copies all files changed since the last lower-level backup--Wednesday's level 5 backup.
On the first Saturday of the month, do a level 5 backup of /export/home, which copies all files changed since the previous lower-level backup--in this case, the level 0 backup you did on Sunday. Store tapes A-F until the first Monday of the next 4-week period, when you use them again.
Repeat steps 1-6 for the next three weeks, using tapes G-L and 4n tapes for the level 0 on Sunday, and so on.
For each 4-week period, repeat steps 1-7, using a new set of tapes for the level 0s and reusing tapes A-X for the incremental backups. The level 0 tapes could be reused after 3 months.
This plan lets you save files in their various states for a month. It requires many tapes, but ensures that you have a library of tapes to draw upon. To reduce the number of tapes, you could reuse Tapes A-F each week.
The table below provides other suggestions for scheduling backups.
Table 42-14 Other Suggestions for Scheduling Backing Up Systems