Откатился до squeeze (всё посносил, убрал репы дотдеба), и потерпел неудачу:
$ siege zenon.sytes.net -d1 -r10 -c25
** SIEGE 2.70
** Preparing 25 concurrent users for battle.
The server is now under siege...
HTTP/1.1 200 9.34 secs: 7846 bytes ==> /
HTTP/1.1 200 9.34 secs: 7846 bytes ==> /
HTTP/1.1 200 9.35 secs: 7846 bytes ==> /
HTTP/1.1 200 9.37 secs: 7846 bytes ==> /
HTTP/1.1 200 9.38 secs: 7846 bytes ==> /
HTTP/1.1 200 9.46 secs: 7846 bytes ==> /
HTTP/1.1 200 9.54 secs: 7846 bytes ==> /
[alert] socket: 1294948096 select timed out: Connection timed out
[alert] socket: 1437624064 select timed out: Connection timed out
[alert] socket: 1370482432 select timed out: Connection timed out
[alert] socket: 1261377280 select timed out: Connection timed out
[alert] socket: 1395660544 select timed out: Connection timed out
[alert] socket: 1269769984 select timed out: Connection timed out
[alert] socket: 1311733504 select timed out: Connection timed out
[alert] socket: 1378875136 select timed out: Connection timed out
[alert] socket: 1404053248 select timed out: Connection timed out
[alert] socket: 1387267840 select timed out: Connection timed out
[alert] socket: 1412445952 select timed out: Connection timed out
[alert] socket: 1429231360 select timed out: Connection timed out
[alert] socket: 1446016768 select timed out: Connection timed out
[alert] socket: 1420838656 select timed out: Connection timed out
[alert] socket: 1353697024 select timed out: Connection timed out
[alert] socket: 1454409472 select timed out: Connection timed out
[alert] socket: 1320126208 select timed out: Connection timed out
[alert] socket: 1286555392 select timed out: Connection timed out
^C
Lifting the server siege... done.
Transactions: 7 hits
Availability: 28.00 %
Elapsed time: 35.89 secs
Data transferred: 0.05 MB
Response time: 9.40 secs
Transaction rate: 0.20 trans/sec
Throughput: 0.00 MB/sec
Concurrency: 1.83
Successful transactions: 7
Failed transactions: 18
Longest transaction: 9.54
Shortest transaction: 0.00Следующая попытка будет с заново чистым установленным squeeze + апач и переносом сайта + мускула через mysqldump.