storage: high write rate roachtest with a large LSM #155363
Description
Motivated by https://github.com/cockroachlabs/support/issues/3457
We should be benchmarking a single node cluster starting with a large LSM (say 1TiB), with a shape that is natural (i.e., not all bytes in L6), and a very high write rate. For the writes, kv0 with large block-bytes (say 512) and high concurrency is good enough. The work here will be to quickly initialize this LSM via a series of ingests that populate L6, L5, ... One possibility is to use external files, then wait until download.
Jira issue: CRDB-55409