The dCache SRM
server requires a PostgreSQL database for request
persistency and link group space accounting. It is recommended
to run SRM
on a dedicated node, preferably with a PostgreSQL
database running on a separate host. The SRM
server has to have
sufficient memory to hold request queues and CPU resources
mainly for GSI
key pair generation. The database host has to
have sufficient I/O and memory resources for optimal database
performance. As a reference Fermilab US-CMS T1 site uses two
dual quad core Intel(R) Xeon(R) CPU E5430 @ 2.66GHz and 32 GB
RAM nodes for SRM
and SRM
database respectively.
Latest Scientific Linux or RHEL would do.
The kernel.shmmax=1073741824 and kernel.shmall=1073741824 kernel parameters should be set for a 4GB RAM Machine. This can be accomplished by running:
[root] #
echo 'kernel.shmmax=1073741824' >> /etc/sysctl.conf
[root] #
echo 'kernel.shmall=1073741824' >> /etc/sysctl.conf
[root] #
/bin/sysctl -p
The exact content of US-CMS T1 SRM
sysctl.conf
is:
kernel.core_uses_pid = 1 kernel.sysrq = 1 kernel.panic = 60 fs.file-max = 131072 net.ipv4.ip_forward = 0 vm.vfs_cache_pressure = 10000 # Keep this amount of memory free for emergency, IRQ and atomic allocations. vm.min_free_kbytes = 65535 # Network tune parameters net.ipv4.tcp_timestamps = 0 net.ipv4.tcp_sack = 0 net.ipv4.tcp_window_scaling = 1 kernel.shmmax=1073741824 kernel.shmall=1073741824