Example—Monthly Backup Schedule for a Server

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 45–12 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:

1. 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.

2. 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).

3. 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.

4. On the first Wednesday, use tape C to do a level 5 backup. The ufsdump command copies all files that changed since Sunday.

5. 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.

6. 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.

7. 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.

8. 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.