Hello All, I am running a polymix-4 test with 3 coss partition. 2 are files (one of them is in memory, tmpfs) and one is a raw partition. I am getting the above message once in a while, not very frequently. Can I safely increase MAX_ASYNCOP ? Does this indicate that the disk is overloaded ? Are there any messages under coss that would suggest that the disk is getting overloaded, similar to the "Queue congestion" message in aufs ? Setup --------------- polymix-4, 700req/s box ----- Dual Core AMD Opteron(tm) Processor 270 HE, 16GB RAM, 2x SATA disks. squid-version ------------------- Squid Cache: Version 2.6.STABLE3 configure options: '--prefix=/usr/squid' '--exec-prefix=/usr/squid' '--sysconfdir=/usr/squid/etc' '--enable-snmp' '--enable-err-languages=English' '--enable-linux-netfilter' '--enable-async-io=24' '--enable-storeio=ufs,aufs,null,coss' '--enable-coss-aio-ops' '--enable-linux-tproxy' '--enable-gnuregex' '--enable-internal-dns' '--enable-epoll' '--with-maxfd=32768' 'CFLAGS=-g -O2 -pg ' squid.conf ---------------- visible_hostname 10.51.6.102 cache_dir coss /mnt/cache/coss 8000 max-size=131072 block-size=512 cache_dir coss /mnt/tmp/coss 7500 max-size=131072 block-size=512 cache_dir coss /dev/sdb1 8000 max-size=131072 block-size=512 http_port 8080 request_body_max_size 0 snmp_port 3401 negative_ttl 0 minutes pid_filename /var/run/squid.pid coredump_dir /var/log/squid cache_effective_user squid cache_effective_group squid cache_access_log /var/log/squid/access.log cache_log /var/log/squid/cache.log cache_store_log none cache_swap_log /var/log/squid/swap.log logfile_rotate 10 icp_port 3130 icp_query_timeout 20000 log_icp_queries on extension_methods SEARCH PROPPATCH forwarded_for on acl all src 0.0.0.0/0.0.0.0 acl localhost src 127.0.0.1 10.51.6.102 acl manager proto cache_object acl snmppublic snmp_community public http_access allow localhost miss_access allow all http_access allow all snmp_access allow snmppublic all memory_pools on cache_mem 1 GB -- Pranav ------------------------------ http://pd.dnsalias.org