I don't understand why.
catch (...)
    {
    }
    try
    {
        if (readString("/sys/kernel/mm/transparent_hugepage/enabled").find("[always]") != std::string::npos)
            server->context()->addWarningMessage("Linux transparent hugepage are set to \"always\".");
    }
    catch (...)
    {
    }
    try
    {
        if (readNumber("/proc/sys/kernel/pid_max") < 30000)
            server->context()->addWarningMessage("Linux max PID is too low.");
    }
    catch (...)
    {
    }
    try
    {
        if (readNumber("/proc/sys/kernel/threads-max") < 30000)
            server->context()->addWarningMessage("Linux threads max count is too low.");
    }
    catch (...)
    {
    }
    std::string dev_id = getBlockDeviceId(data_path);
    if (getBlockDeviceType(dev_id) == BlockDeviceType::ROT && getBlockDeviceReadAheadBytes(dev_id) == 0)
        server->context()->addWarningMessage("Rotational disk with disabled readahead is in use. Performance can be degraded.");