Hi,all: Our squid box's performance is not very good(40000 reqs/min), cpu load is very high, and the traffic can't great bigger than 100MBits/s.(Gbits/s network). We use aufs scheme now.We have a test for coss, and the result is not very good also(cpu overload also). can we optimize continue?Is the best performace that our hardware can achived?where is the bottle-neck? what is the best performance of your box? there are some infomations: ++++++ hardware: cpu: Xeon 1.8G(Hyper-Threading) os: RHAS 4.3 file discriptor num: 32768 mem: 2G disk: OS: 17G(scsi) for OS, cache:73G(SCSI,10000rpm for cache data) ++++++ squid.conf about 100 ACLs cache_mem 1500 MB cache_dir coss /dev/sdb1 50000 max-size=10000000 block-size=8192 (some server use aufs: cache_dir aufs /cache/cache 50000 240 256, and sdb1 is mounted with options of async and noatime) ++++++ top: top - 11:37:46 up 42 days, 12:00, 1 user, load average: 1.00, 0.99, 0.91 Tasks: 54 total, 3 running, 51 sleeping, 0 stopped, 0 zombie Cpu(s): 41.8% us, 8.3% sy, 0.0% ni, 47.9% id, 1.3% wa, 0.7% hi, 0.0% si Mem: 2074980k total, 1979160k used, 95820k free, 686568k buffers Swap: 4192956k total, 3404k used, 4189552k free, 355632k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3738 squid 25 0 918m 714m 2104 R 99.9 35.3 63:59.56 squid 3901 root 16 0 3664 912 740 R 0.3 0.0 0:00.04 top 1 root 16 0 3312 236 208 S 0.0 0.0 0:04.01 init ++++++ mgr:info Squid Object Cache: Version 2.6.STABLE12 Start Time: Thu, 22 Mar 2007 02:34:09 GMT Current Time: Thu, 22 Mar 2007 03:21:32 GMT Connection information for squid: Number of clients accessing cache: 9967 Number of HTTP requests received: 1705959 Number of ICP messages received: 0 Number of ICP messages sent: 0 Number of queued ICP replies: 0 Request failure ratio: 0.00 Average HTTP requests per minute since start: 36012.7 Average ICP messages per minute since start: 0.0 Select loop called: 1805771 times, 1.574 ms avg Cache information for squid: Request Hit Ratios: 5min: 97.9%, 60min: 97.6% Byte Hit Ratios: 5min: 83.9%, 60min: 78.7% Request Memory Hit Ratios: 5min: 9.6%, 60min: 18.2% Request Disk Hit Ratios: 5min: 16.3%, 60min: 7.5% Storage Swap size: 240512 KB Storage Mem size: 241140 KB Mean Object Size: 26.95 KB Requests given to unlinkd: 0 Median Service Times (seconds) 5 min 60 min: HTTP Requests (All): 0.00919 0.00562 Cache Misses: 0.09736 0.10281 Cache Hits: 0.00919 0.00562 Near Hits: 0.06640 0.05331 Not-Modified Replies: 0.00865 0.00463 DNS Lookups: 0.03868 0.06364 ICP Queries: 0.00000 0.00000 Resource usage for squid: UP Time: 2842.262 seconds CPU Time: 2911.327 seconds CPU Usage: 102.43% CPU Usage, 5 minute avg: 87.11% CPU Usage, 60 minute avg: 102.57% Process Data Segment Size via sbrk(): 378764 KB Maximum Resident Size: 0 KB Page faults with physical i/o: 0 Memory usage for squid via mallinfo(): Total space in arena: 378764 KB Ordinary blocks: 297942 KB 10127 blks Small blocks: 0 KB 0 blks Holding blocks: 401944 KB 6 blks Free Small blocks: 0 KB Free Ordinary blocks: 80821 KB Total in use: 699886 KB 90% Total free: 80821 KB 10% Total size: 780708 KB Memory accounted for: Total accounted: 552999 KB memPoolAlloc calls: 147261049 memPoolFree calls: 147041272 File descriptor usage for squid: Maximum number of file descriptors: 32768 Largest file desc currently in use: 6319 Number of file desc currently in use: 5784 Files queued for open: 0 Available number of file descriptors: 26984 Reserved number of file descriptors: 100 Store Disk files open: 0 IO loop method: epoll Internal Data Structures: 8976 StoreEntries 4571 StoreEntries with MemObjects 4537 Hot Object Cache Items 8924 on-disk objects -- Best regards Felix New