What is the acceptable speed when restoring from tape (LTO4)

[kkhoo]

Hi,

So we are doing test restore from tape. What is the ideal speed when restoring from LTO4 tape? Is it the same when we backup to tape?

[RiaanBadenhorst]

The performance depends on the data. Having few large data files will usually give you better performance as compared to many small files eg database vs file server. This would apply to both backups and restores.

Additionally, multiplexing (it backing up to tape) also influences the performance. If you have a high level of multiplexing you might see improved backup times but restores will be slower.

[kkhoo]

@RiaanBadenhorst

Thanks for quick reply. is 922MB/min restore from considered ideal?

This is db restore and yes this is many small files.

[RiaanBadenhorst]

Like i said, each situation is different. What is the backup speed?

[kkhoo]

36963 KB/sec

[mph999]

Was the backup multiplexed ?  If so, what mpx value was used.

[sdo]

for anyone else looking:

restore was:  922MB/min = 15 MB/s = 15735KB/s

.

I'd like to know what your "waits" and "delays" were for the restore job.  See:

https://www.veritas.com/support/en_US/article.000010401

.

A word of advice:  Do not change the buffer/tuning files until you fully understand what the problem is.

[mph999]

Excellent advice SDO - the number of times I have seen that happen, even when it turns out the buffer settings had nothing to do with the issue ....