This section provides sample backup schedules. All schedules assume that you begin with a full backup (dump level 0), and that you use the -u option to record each backup.
The following table shows the most commonly used incremental backup schedule. This schedule is recommended for most situations. With this schedule, the following occurs:
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 that 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 following table shows how the contents of the tapes can change across two weeks with the daily cumulative, weekly cumulative schedule. Each letter represents a different file.
Table 46–7 Contents of Tapes for Daily Cumulative/Weekly Cumulative 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 |
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 tape for the level 0, four tapes for Fridays, and one or four daily tapes.
If you need to restore a complete file system, you 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 following table 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 that changed that week.
Table 46–8 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 following table shows how the contents of the tapes can change across two weeks with the daily cumulative, weekly incremental backup schedule. Each letter represents a different file.
Table 46–9 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 tape for the level 0, four tapes for 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 following table shows a schedule where each weekday tape contains only the files that 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 46–10 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 following table shows how the contents of the tapes can change across two weeks with the daily incremental, weekly cumulative schedule. Each letter represents a different file.
Table 46–11 Contents of Tapes for Daily Incremental, 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, which is not recommended. Or, you need 21 tapes if you save weekly tapes for a month: one tape for the level 0, four tapes 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 following table 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. This example assumes that the backup period begins on a Sunday and consists of four seven-day weeks.
Table 46–12 Example of Monthly Backup Schedule for a Server
Directory |
Date |
Level |
Tape Name |
---|---|---|---|
root (/) |
1st Sunday |
0 |
n tapes |
/usr |
1st Sunday |
0 |
n tapes |
/export |
1st Sunday |
0 |
n tapes |
/export/home |
1st Sunday |
0 |
n tapes |
|
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 schedule, you use 4n tapes, the number of tapes needed for four full backups of the root (/), /usr, /export, and /export/home file systems, plus 24 additional tapes for the incremental backups of the /export/home file systems. This schedule assumes that each incremental backup uses one tape and that you save the tapes for a month.
Here's how this schedule works:
On each Sunday, do a full backup (level 0) of the root (/), /usr, /export, and /export/home file systems. 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 the /export/home file system. The ufsdump command 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 the /export/home file system. Again, the ufsdump command copies all files changed since the last lower-level backup, which is Sunday's level 0 backup.
On the first Wednesday, use tape C to do a level 5 backup. The ufsdump command copies all files that changed since Sunday.
Do the Thursday and Friday level 9 backups on tapes D and E. The ufsdump command copies all files that changed since the last lower-level backup, which is 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 schedule lets you save files in their various states for a month. This plan 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 following table provides other suggestions for scheduling backups.
Table 46–13 Suggestions for Backup Schedules