Recommended Checkpoint interval

It is possible

I would negotiate for a lower number though. For example 10 min for an hour and then hourly checkpoints

6 x 24 = 144 – if you have more file systems then you need to consider the total amount of file system + checkpoints per system

This also has an influence on the boot and failover time.

andre.rossouw

Can anyone answer this question please , this asked couple of times but I couldn't find any answer for it.

Thank you

I think Rainer provided an answer above.  One thing to consider - there is a limit to the total number of checkpoints per filesystem; 144 exceeds that limit.  Moreover, having more checkpoints per filesystem increases the time required to failover or reboot a datamover.  Rainer's recommendation - 10 minute checkpoints, saved for an hour + hourly checkpoints, saved for a day - is very reasonable.

In our environment, I keep a checkpoint every four hours for a day, seven daily checkpoints for a week and four weekly checkpoints for a month.  This allowed users great flexibility and dropped our help desk calls for restores dramatically.

Let us know if that helps!

Karl

Thanks @Karl,

Your explanation is clear but I', still confused. I think the check point limit is 96. You calculated:

6 (checkpoints per hour) * 24 (retention) = 144 which exceeds 96. Then you recalculated:

The question asking about checkpoint interval and answers are:

20

30

60

45

and 20 is the correct answer, how we get 20 ?@

The limit to the total number of checkpoints per filesystem is 96.  What Rainer was illustrating was that 6 X 24 = 144 which is too many checkpoints.  He was illustrating that to the original poster, so that the poster could negotiate fewer checkpoints with his customers.

The rest of your question, I don't understand - it looks like you're asking something from the VNX TA exam.

Repost the question here and I'll have a look!

Appreciate your help,

A customer has a requirement for their CIFS home directories, they want checkpoint every 10 minutes and 24h data retention, self-service file level recovery.

What checkpoint interval do you recommend ?

20

30

60

45

I need some help in couple of questions and I couldn't find any answer for them, is there anyone we can refer to ask e20-324 related questions?

just because customer wants snapshot every 10 minutes and keep for 24 hours does not mean the system can accommodate that. That's 6 x 24 = 144 , obviously 144 is more than Celerra/VNX supports at the moment (max 96 snapshots per file system) so your next recommendation is 20 minute interval (3 x 24 = 72)

Thanks dynamox for your perfect explanation.

hi Karl,

Is there anyone who can help with e20-324 questions? I am really confused about some calculations and I couldn't find any help for that.

Thanks,