When recovery is slower than you can afford.
WHY IT MATTERS
Recovery time is part of your plan. A restore taking eight hours is a different proposition from one taking twenty minutes.
WHAT MAKES RESTORES SLOW
Very large archives Large databases importing through phpMyAdmin Many small files, which transfer slowly Restoring everything when only part is needed
MAKING IT FASTER
Restore selectively. If only the database is affected, restore only the database. Use the command line for large database imports. Keep separate per-site backups on multi-site accounts, so you restore one rather than all. Keep archives compressed and transfer once rather than file by file.
REDUCING WHAT NEEDS RESTORING
Keep media off the critical path. If images are backed up separately, the site can be restored and working while media restores afterwards.
PLANNING FOR IT
Time a restore during a test. Then you know, rather than discovering during an incident.
IF IT IS GENUINELY TOO SLOW
Consider whether the site has outgrown the arrangement, and whether a different approach or a different plan is warranted.
