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.