4 Week cycle tape backups

[Kerplunk]

We have a 4 week cycle tape backup schedule here at work, but im curious to know how you would perceive this.

Okay, so this is how it goes:

Monday Tuesday Wednesday Thursday Friday
Week 1
Monday-1
Tuesday-1
Wednesday-1
Thursday-1
Friday-1

Week 2
Monday-2
Tuesday-2
Wednesday-2
Thursday-2
Friday-2

Week 3
Monday-3
Tuesday-3
Wednesday-3
Thursday-3
Friday-3

Week 4
Monday-4
Tuesday-4
Wednesday-4
Thursday-4
Friday-4

At which point would you withdraw a tape (s)? My understanding is that on the last day of the month all those tapes are in effect that months backups, Okay the part that I dont understand is do you withdraw all of them ? or do you just overwrite them? (assuming you dont!).

If anyone has experience with this, then i'd like to hear what you do or at least any idea.

 

[Gman]

I think where I last worked we just overwrote the oldest ones each time.

 

[masterk]

The way ive always known it is that day 5's backup is actually a permanent backup.

If you delete something important, and then a month later need it again you would have it if you had a permanent backup.

 

[Dr_Evil]

So how many physical Tapes/Drives do you have?

We have the following Drives, with the following labels:

Monday
Tuesday
Wednesday
Thursday
Friday 1
Friday 2
Friday 3
Friday 4

so, the Mon-Thu tapes are overwritten weekly on that day, and the Friday ones are "cycled" so we always have a backup from 3 Fridays ago.

 

[gyro]

We currently have

Monday
Tuesday
Wednesday
Thursday
Friday 1
Friday 2

Lee

 

[Uhtred]

we have 4 differental backup jobs on monday-thursday. full backup on friday which is in a 4 week rotation, just overwrites the old tapes. then a monthly full backup on the last day of each month which is kept for good.

We also keep snapshots every hour of every file that has changed which, i believe, is also backed up to tape at the end of the month as well.

 

[Dr_Evil]

Yes - Windows Shadow Copies I believe that is called - you can create "snapshots" of all files in certain folders/drives every x amount of time, quite handy in rolling back to previous versions.

 

[bledd]

where i worked last we had a 4 week cycle like you have, but we'd keep one a month, usually around the 1st, that would be taken out and stored at home

 

[benjo plz.]

Tbh, you should always have an offsite backup.

 

[oddjob62]

Mon / Tue / Wed / Thu
Fri1 / Fri2 / Fri3 / Fri4
Jan / Feb / March... etc etc

So 20 tapes needed (plus any for year end)

 

[Silent Bob]

I do 1 full backup each week (every Friday) and then do incrementals the rest of the days onto a single tape.

Then every 4th Fridays full backup I label as a monthly backup and keep it for 6 months until I overwrite it. Like this:

Week 1:
Incremental tape A (mon-thu)
Weekly tape A


Week 2:
Incremental tape B (mon-thu)
Weekly tape B


Week 3:
Incremental tape A (mon-thu)
Weekly tape C

Week 4:
Incremental tape B (mon-thu)
Monthly tape (x)

Then every week 4 I cyle between monthly tape (A,B,C,D,E,F). That means I always have a daily backup of the last 2 weeks, a weekly backup of the last 4 weeks and a monthly backup of the last 6 months.

 

[iBot]

dont bother backing anything up, people like fresh starts.

 

[Slinwagh]

So how many physical Tapes/Drives do you have?

We have the following Drives, with the following labels:

Monday
Tuesday
Wednesday
Thursday
Friday 1
Friday 2
Friday 3
Friday 4

so, the Mon-Thu tapes are overwritten weekly on that day, and the Friday ones are "cycled" so we always have a backup from 3 Fridays ago.

I have always run backups like that plus 12 end of month tapes. it never let me down.

 

[Stelly]

I have always run backups like that plus 12 end of month tapes. it never let me down.

Agreed... hell of a lot of money on tapes... we have 4 tapes for each backup using LTO2...

Stelly

 

[Slinwagh]

Agreed... hell of a lot of money on tapes... we have 4 tapes for each backup using LTO2...

Stelly

I think you have to balance that against how valuable is the data and can the business function without sufficient backups?

 

[Valo]

We recommend it this way at my work:

Tape 1 - Monday (Daily Tape)
Tape 2 - Tuesday (Daily Tape)
Tape 3 - Wednesday (Daily Tape)
Tape 4 - Thursday (Daily Tape)
Tape 5 - Friday (Week 1)
Tape 6 - Friday (Week 2)
Tape 7 - Friday (Week 3)
Tape 8 - Friday (Month 1)
Tape 9 - Friday (Month 2)
Tape 10 - Friday (Month 3)

Use tapes 1-5 for your daily backups, tapes 5-7 for your weekly backups and tapes 8-10 for the monthly backups. You could at tape 11 and make that a yearly backup as well. This system also makes it easy for tape rotation.

 

[Dr_Evil]

Question - why would you need a backup from 3 months ago, when you have one from a week ago at hand? Would you ever need to go back that far?

 

[Kerplunk]

Thanks for all the informative replies guys.

Question - why would you need a backup from 3 months ago, when you have one from a week ago at hand? Would you ever need to go back that far?

This is the very reason, why I posted this thread. A user here wanted to go back to June (in November) and I thought that id I just looked at which backup tape was created on that day it would be there. But no.

From what I can see on our magical little Backup Exec, you seem to get a months worth of media information 1 - 31 of a month (depending on month).

Anyway, The question I was asking myself is how would this data of been kept/backed up if Every 4 weeks the tapes had been overwritten.

Okay, some nub might of made a drastic error and needed to go back but didnt notice until just now? :/

So, are people here sayign that On 'fridays' you should withdraw the tape and store them?

Perhaps im missing something blatently obvious but I dont see how you can have all data backed up and refer back to a specific file from January 06.

 

[Shoei]

Have 20 tapes in the cycle plus 6 monthly tapes.
So you start at Tape1 and just go round till you get to Tape1 again.
The backup from Friday goes off site for insurance purposes.
The monthly goes off site and the previous monthly tape comes back on site but into the fire safe.
Currently backing up 520Gb to Ultrium 960 tape from umpteen servers.

 

[Shoei]

Question - why would you need a backup from 3 months ago, when you have one from a week ago at hand? Would you ever need to go back that far?

Oh yes. Users like to have stuff from way back just to test the backups out.
Furthest ive gone back is 6 months to find a file or an email.