On Oct 26, 2010, at 10:35 AM, heikel, cory wrote:
> A question for the brain trust...
>
> I have many clients with an average daily change rate of over 50%. Most of
> these clients take several hours to back up and show a high percentage of
> wait time in the summary table. My question is this: Would it make sense for
> these clients to be backed up full each day instead of incremental?
Your client is likely busy trawling the file system(s) for backup candidates
during the time the TSM server is waiting for something from it. Some
platforms support Journal-Based Backups, which can be used to effectively
eliminate that. (I'd expect relatively modest IdleWait time with a 50% churn
rate, though: the file system may be busy at the time, slowing access, or the
Active files complement held by the client during the Incremental is a burden
for the memory of that system, resulting in substantial slow-down paging. Pore
over a sample scheduler log, looking for anomalies, and examining the deltas on
the timestamps for progress reasonableness.)
Full backups would still traverse the whole file system and, worse, send all
the data in it - which congests the networking, inflates storage pool
utilization, and creates issues with number of versions available (which can
render go-back restoral impossible).
Richard Sims
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