Cache Wipe upon Crash survival

[edmiri]

Cache wipe is frustrating.
Can we have 2 parallel level 2 caches in 2 different partitions.
First one operates normally while the second one delay the saving so if a system crash happens it is not affected by it.
When the system rebots it uses the delayed non affected cache and automatically make a copy of it in the wiped cache partition.
We can do this using 2 partitions from the same ssd or 2 different ssd.

[Jaga]

There's a special option you can toggle on to accomplish this, it's visible in the Advanced Level-2 Cache Options, called "Ignore Sync Check and Preserve Cache Anyway". You can turn it on through the rxpcc command line utility. It isn't recommended obviously, since it could start using a corrupted L2 cache.

A secondary or tertiary L2 would be an interesting safety mechanism, coupled with verified/journaled writes. Not sure how much work would be involved though.