1 collectd - System information collection daemon
2 =================================================
8 collectd is a small daemon which collects system information periodically
9 and provides mechanisms to store and monitor the values in a variety of
16 * collectd is able to collect the following data:
19 Apache server utilization: Number of bytes transferred, number of
20 requests handled and detailed scoreboard statistics
23 APC UPS Daemon: UPS charge, load, input/output/battery voltage, etc.
26 Sensors in Macs running Mac OS X / Darwin: Temperature, fan speed and
30 Various sensors in the Aquaero 5 water cooling board made by Aquacomputer.
33 Statistics about Ascent, a free server for the game `World of Warcraft'.
36 Using digital barometer sensor MPL115A2 or MPL3115 from Freescale
37 provides absolute barometric pressure, air pressure reduced to sea level
41 Batterycharge, -current and voltage of ACPI and PMU based laptop
45 Name server and resolver statistics from the `statistics-channel'
46 interface of BIND 9.5, 9,6 and later.
49 CPU accounting information for process groups under Linux.
52 Number of nf_conntrack entries.
55 Number of context switches done by the operating system.
58 CPU utilization: Time spent in the system, user, nice, idle, and related
62 CPU frequency (For laptops with speed step or a similar technology)
65 Parse statistics from websites using regular expressions.
68 Retrieves JSON data via cURL and parses it according to user
72 Retrieves XML data via cURL and parses it according to user
76 Executes SQL statements on various databases and interprets the returned
80 Mountpoint usage (Basically the values `df(1)' delivers)
83 Disk utilization: Sectors read/written, number of read/write actions,
84 average time an IO-operation took to complete.
87 DNS traffic: Query types, response codes, opcodes and traffic/octets
91 Collect individual drbd resource statistics.
94 Email statistics: Count, traffic, spam scores and checks.
95 See collectd-email(5).
98 Amount of entropy available to the system.
101 Network interface card statistics.
104 Values gathered by a custom program or script.
105 See collectd-exec(5).
108 Count the number of files in directories.
111 Linux file-system based caching framework statistics.
114 Receive multicast traffic from Ganglia instances.
117 Hard disk temperatures using hddtempd.
120 Interface traffic: Number of octets, packets and errors for each
124 Iptables' counters: Number of bytes that were matched by a certain
128 IPMI (Intelligent Platform Management Interface) sensors information.
131 IPVS connection statistics (number of connections, octets and packets
132 for each service and destination).
133 See http://www.linuxvirtualserver.org/software/index.html.
136 IRQ counters: Frequency in which certain interrupts occur.
139 Integrates a `Java Virtual Machine' (JVM) to execute plugins in Java
140 bytecode. See “Configuring with libjvm” below.
143 System load average over the last 1, 5 and 15 minutes.
146 Detailed CPU statistics of the “Logical Partitions” virtualization
147 technique built into IBM's POWER processors.
150 CPU, memory, disk and network I/O statistics from virtual machines.
153 Size of “Logical Volumes” (LV) and “Volume Groups” (VG) of Linux'
154 “Logical Volume Manager” (LVM).
157 Queries very detailed usage statistics from wireless LAN adapters and
158 interfaces that use the Atheros chipset and the MadWifi driver.
161 Motherboard sensors: temperature, fan speed and voltage information,
165 Linux software-RAID device information (number of active, failed, spare
169 Query and parse data from a memcache daemon (memcached).
172 Statistics of the memcached distributed caching system.
173 <http://www.danga.com/memcached/>
176 Memory utilization: Memory occupied by running processes, page cache,
177 buffer cache and free.
180 Collects CPU usage, memory usage, temperatures and power consumption from
181 Intel Many Integrated Core (MIC) CPUs.
184 Reads values from Modbus/TCP enabled devices. Supports reading values
185 from multiple "slaves" so gateway devices can be used.
188 Information provided by serial multimeters, such as the `Metex
192 MySQL server statistics: Commands issued, handlers triggered, thread
193 usage, query cache utilization and traffic/octets sent and received.
196 Plugin to query performance values from a NetApp storage system using the
197 “Manage ONTAP” SDK provided by NetApp.
200 Very detailed Linux network interface and routing statistics. You can get
201 (detailed) information on interfaces, qdiscs, classes, and, if you can
202 make use of it, filters.
205 Receive values that were collected by other hosts. Large setups will
206 want to collect the data on one dedicated machine, and this is the
207 plugin of choice for that.
210 NFS Procedures: Which NFS command were called how often. Only NFSv2 and
214 Collects statistics from `nginx' (speak: engine X), a HTTP and mail
218 NTP daemon statistics: Local clock drift, offset to peers, etc.
221 Network UPS tools: UPS current, voltage, power, charge, utilisation,
222 temperature, etc. See upsd(8).
225 Information about Non-Uniform Memory Access (NUMA).
228 Queries routing information from the “Optimized Link State Routing”
231 - onewire (EXPERIMENTAL!)
232 Read onewire sensors using the owcapu library of the owfs project.
233 Please read in collectd.conf(5) why this plugin is experimental.
236 RX and TX of each client in openvpn-status.log (status-version 2).
237 <http://openvpn.net/index.php/documentation/howto.html>
240 Query data from an Oracle database.
243 The perl plugin implements a Perl-interpreter into collectd. You can
244 write your own plugins in Perl and return arbitrary values using this
245 API. See collectd-perl(5).
248 Query statistics from BSD's packet filter "pf".
251 Receive and dispatch timing values from Pinba, a profiling extension for
255 Network latency: Time to reach the default gateway or another given
259 PostgreSQL database statistics: active server connections, transaction
260 numbers, block IO, table row manipulations.
263 PowerDNS name server statistics.
266 Process counts: Number of running, sleeping, zombie, ... processes.
269 Counts various aspects of network protocols such as IP, TCP, UDP, etc.
272 The python plugin implements a Python interpreter into collectd. This
273 makes it possible to write plugins in Python which are executed by
274 collectd without the need to start a heavy interpreter every interval.
275 See collectd-python(5) for details.
278 The redis plugin gathers information from a Redis server, including:
279 uptime, used memory, total connections etc.
282 Query interface and wireless registration statistics from RouterOS.
285 RRDtool caching daemon (RRDcacheD) statistics.
288 System sensors, accessed using lm_sensors: Voltages, temperatures and
292 RX and TX of serial interfaces. Linux only; needs root privileges.
295 Uses libsigrok as a backend, allowing any sigrok-supported device
296 to have its measurements fed to collectd. This includes multimeters,
297 sound level meters, thermometers, and much more.
300 Read values from SNMP (Simple Network Management Protocol) enabled
301 network devices such as switches, routers, thermometers, rack monitoring
302 servers, etc. See collectd-snmp(5).
305 Acts as a StatsD server, reading values sent over the network from StatsD
306 clients and calculating rates and other aggregates out of these values.
309 Pages swapped out onto hard disk or whatever is called `swap' by the OS..
312 Parse table-like structured files.
315 Follows (tails) log files, parses them by lines and submits matched
319 Follows (tails) files in CSV format, parses each line and submits
323 Bytes and operations read and written on tape devices. Solaris only.
326 Number of TCP connections to specific local and remote ports.
329 TeamSpeak2 server statistics.
332 Plugin to read values from `The Energy Detective' (TED).
335 Linux ACPI thermal zone information.
338 Reads the number of records and file size from a running Tokyo Tyrant
342 System uptime statistics.
345 Users currently logged in.
348 Various statistics from Varnish, an HTTP accelerator.
351 Virtual memory statistics, e. g. the number of page-ins/-outs or the
352 number of pagefaults.
355 System resources used by Linux VServers.
356 See <http://linux-vserver.org/>.
359 Link quality of wireless cards. Linux only.
362 Bitrate and frequency of music played with XMMS.
365 Statistics for ZFS' “Adaptive Replacement Cache” (ARC).
367 * Output can be written or sent to various destinations by the following
371 Sends JSON-encoded data to an Advanced Message Queuing Protocol (AMQP)
372 server, such as RabbitMQ.
375 Write to comma separated values (CSV) files. This needs lots of
376 diskspace but is extremely portable and can be analysed with almost
377 every program that can analyse anything. Even Microsoft's Excel..
380 Send the data to a remote host to save the data somehow. This is useful
381 for large setups where the data should be saved by a dedicated machine.
384 Of course the values are propagated to plugins written in Perl, too, so
385 you can easily do weird stuff with the plugins we didn't dare think of
386 ;) See collectd-perl(5).
389 It's possible to implement write plugins in Python using the python
390 plugin. See collectd-python(5) for details.
393 Output to round-robin-database (RRD) files using the RRDtool caching
394 daemon (RRDcacheD) - see rrdcached(1). That daemon provides a general
395 implementation of the caching done by the `rrdtool' plugin.
398 Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
399 This is likely the most popular destination for such values. Since
400 updates to RRD-files are somewhat expensive this plugin can cache
401 updates to the files and write a bunch of updates at once, which lessens
405 One can query the values from the unixsock plugin whenever they're
406 needed. Please read collectd-unixsock(5) for a description on how that's
410 Sends data to Carbon, the storage layer of Graphite using TCP or UDP. It
411 can be configured to avoid logging send errors (especially useful when
415 Sends data OpenTSDB, a scalable no master, no shared state time series
419 Sends the values collected by collectd to a web-server using HTTP POST
420 requests. The transmitted data is either in a form understood by the
421 Exec plugin or formatted in JSON.
424 Sends data to Apache Kafka, a distributed queue.
427 Sends data to MongoDB, a NoSQL database.
430 Sends the values to a Redis key-value database server.
433 Sends data to Riemann, a stream processing and monitoring system.
435 * Logging is, as everything in collectd, provided by plugins. The following
436 plugins keep up informed about what's going on:
439 Writes log messages to a file or STDOUT/STDERR.
442 Log messages are propagated to plugins written in Perl as well.
443 See collectd-perl(5).
446 It's possible to implement log plugins in Python using the python plugin.
447 See collectd-python(5) for details.
450 Logs to the standard UNIX logging mechanism, syslog.
453 Writes log messages formatted as logstash JSON events.
455 * Notifications can be handled by the following plugins:
458 Send a desktop notification to a notification daemon, as defined in
459 the Desktop Notification Specification. To actually display the
460 notifications, notification-daemon is required.
461 See http://www.galago-project.org/specs/notification/.
464 Send an E-mail with the notification message to the configured
468 Execute a program or script to handle the notification.
469 See collectd-exec(5).
472 Writes the notification message to a file or STDOUT/STDERR.
475 Send the notification to a remote host to handle it somehow.
478 Notifications are propagated to plugins written in Perl as well.
479 See collectd-perl(5).
482 It's possible to implement notification plugins in Python using the
483 python plugin. See collectd-python(5) for details.
485 * Value processing can be controlled using the "filter chain" infrastructure
486 and "matches" and "targets". The following plugins are available:
488 - match_empty_counter
489 Match counter values which are currently zero.
492 Match values using a hash function of the hostname.
495 Match values by their identifier based on regular expressions.
498 Match values with an invalid timestamp.
501 Select values by their data sources' values.
503 - target_notification
504 Create and dispatch a notification.
507 Replace parts of an identifier using regular expressions.
510 Scale (multiply) values by an arbitrary value.
513 Set (overwrite) entire parts of an identifier.
515 * Miscellaneous plugins:
518 Selects multiple value lists based on patterns or regular expressions
519 and creates new aggregated values lists from those.
522 Checks values against configured thresholds and creates notifications if
523 values are out of bounds. See collectd-threshold(5) for details.
526 Sets the hostname to a unique identifier. This is meant for setups
527 where each client may migrate to another physical host, possibly going
528 through one or more name changes in the process.
530 * Performance: Since collectd is running as a daemon it doesn't spend much
531 time starting up again and again. With the exception of the exec plugin no
532 processes are forked. Caching in output plugins, such as the rrdtool and
533 network plugins, makes sure your resources are used efficiently. Also,
534 since collectd is programmed multithreaded it benefits from hyper-threading
535 and multicore processors and makes sure that the daemon isn't idle if only
536 one plugin waits for an IO-operation to complete.
538 * Once set up, hardly any maintenance is necessary. Setup is kept as easy
539 as possible and the default values should be okay for most users.
545 * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
546 Run `collectd -h' for a list of built-in defaults. See `collectd.conf(5)'
547 for a list of options and a syntax description.
549 * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
550 files. The usual place for these files is beneath `/var/lib/collectd'.
552 * When using some of the plugins, collectd needs to run as user root, since
553 only root can do certain things, such as craft ICMP packages needed to ping
554 other hosts. collectd should NOT be installed setuid root since it can be
555 used to overwrite valuable files!
557 * Sample scripts to generate graphs reside in `contrib/' in the source
558 package or somewhere near `/usr/share/doc/collectd' in most distributions.
559 Please be aware that those script are meant as a starting point for your
560 own experiments.. Some of them require the `RRDs' Perl module.
561 (`librrds-perl' on Debian) If you have written a more sophisticated
562 solution please share it with us.
564 * The RRAs of the automatically created RRD files depend on the `step'
565 and `heartbeat' settings given. If change these settings you may need to
566 re-create the files, losing all data. Please be aware of that when changing
567 the values and read the rrdtool(1) manpage thoroughly.
570 collectd and chkrootkit
571 -----------------------
573 If you are using the `dns' plugin chkrootkit(1) will report collectd as a
574 packet sniffer ("<iface>: PACKET SNIFFER(/usr/sbin/collectd[<pid>])"). The
575 plugin captures all UDP packets on port 53 to analyze the DNS traffic. In
576 this case, collectd is a legitimate sniffer and the report should be
577 considered to be a false positive. However, you might want to check that
578 this really is collectd and not some other, illegitimate sniffer.
584 To compile collectd from source you will need:
586 * Usual suspects: C compiler, linker, preprocessor, make, ...
588 * A POSIX-threads (pthread) implementation.
589 Since gathering some statistics is slow (network connections, slow devices,
590 etc) collectd is parallelized. The POSIX threads interface is being
591 used and should be found in various implementations for hopefully all
594 * aerotools-ng (optional)
595 Used by the `aquaero' plugin. Currently, the `libaquaero5' library, which
596 is used by the `aerotools-ng' toolkit, is not compiled as a shared object
597 nor does it feature an installation routine. Therefore, you need to point
598 collectd's configure script at the source directory of the `aerotools-ng'
600 <https://github.com/lynix/aerotools-ng>
602 * CoreFoundation.framework and IOKit.framework (optional)
603 For compiling on Darwin in general and the `apple_sensors' plugin in
605 <http://developer.apple.com/corefoundation/>
607 * libclntsh (optional)
608 Used by the `oracle' plugin.
610 * libcredis (optional)
611 Used by the `redis' plugin. Please note that you require a 0.2.2 version
612 or higher. <http://code.google.com/p/credis/>
615 If you want to use the `apache', `ascent', `bind', `curl', `curl_json',
616 `curl_xml', `nginx', or `write_http' plugin.
617 <http://curl.haxx.se/>
620 Used by the `dbi' plugin to connect to various databases.
621 <http://libdbi.sourceforge.net/>
623 * libesmtp (optional)
624 For the `notify_email' plugin.
625 <http://www.stafford.uklinux.net/libesmtp/>
627 * libganglia (optional)
628 Used by the `gmond' plugin to process data received from Ganglia.
629 <http://ganglia.info/>
631 * libgcrypt (optional)
632 Used by the `network' plugin for encryption and authentication.
633 <http://www.gnupg.org/>
636 If present, the `uuid' plugin will check for UUID from HAL.
637 <http://hal.freedesktop.org/>
639 * libi2c-dev (optional)
640 Used for the plugin `barometer', provides just the i2c-dev.h header file
641 for user space i2c development.
644 For querying iptables counters.
645 <http://netfilter.org/>
648 Library that encapsulates the `Java Virtual Machine' (JVM). This library is
649 used by the `java' plugin to execute Java bytecode. See “Configuring with
651 <http://openjdk.java.net/> (and others)
654 Used by the `lvm' plugin.
655 <ftp://sources.redhat.com/pub/lvm2/>
657 * libmemcached (optional)
658 Used by the `memcachec' plugin to connect to a memcache daemon.
659 <http://tangent.org/552/libmemcached.html>
662 Used by the `netlink' plugin.
663 <http://www.netfilter.org/projects/libmnl/>
665 * libmodbus (optional)
666 Used by the `modbus' plugin to communicate with Modbus/TCP devices. The
667 `modbus' plugin works with version 2.0.3 of the library – due to frequent
668 API changes other versions may or may not compile cleanly.
669 <http://www.libmodbus.org/>
671 * libmysqlclient (optional)
672 Unsurprisingly used by the `mysql' plugin.
673 <http://dev.mysql.com/>
675 * libnetapp (optional)
676 Required for the `netapp' plugin.
677 This library is part of the “Manage ONTAP SDK” published by NetApp.
679 * libnetsnmp (optional)
680 For the `snmp' plugin.
681 <http://www.net-snmp.org/>
683 * libnotify (optional)
684 For the `notify_desktop' plugin.
685 <http://www.galago-project.org/>
687 * libopenipmi (optional)
688 Used by the `ipmi' plugin to prove IPMI devices.
689 <http://openipmi.sourceforge.net/>
691 * liboping (optional)
692 Used by the `ping' plugin to send and receive ICMP packets.
693 <http://octo.it/liboping/>
695 * libowcapi (optional)
696 Used by the `onewire' plugin to read values from onewire sensors (or the
698 <http://www.owfs.org/>
701 Used to capture packets by the `dns' plugin.
702 <http://www.tcpdump.org/>
704 * libperfstat (optional)
705 Used by various plugins to gather statistics under AIX.
708 Obviously used by the `perl' plugin. The library has to be compiled with
709 ithread support (introduced in Perl 5.6.0).
710 <http://www.perl.org/>
713 The PostgreSQL C client library used by the `postgresql' plugin.
714 <http://www.postgresql.org/>
716 * libprotobuf-c, protoc-c (optional)
717 Used by the `pinba' plugin to generate a parser for the network packets
718 sent by the Pinba PHP extension, and by the `write_riemann' plugin to
719 generate events to be sent to a Riemann server.
720 <http://code.google.com/p/protobuf-c/>
722 * libpython (optional)
723 Used by the `python' plugin. Currently, Python 2.3 and later and Python 3
725 <http://www.python.org/>
727 * librabbitmq (optional; also called “rabbitmq-c”)
728 Used by the `amqp' plugin for AMQP connections, for example to RabbitMQ.
729 <http://hg.rabbitmq.com/rabbitmq-c/>
731 * librdkafka (optional; also called “rdkafka”)
732 Used by the `write_kafka' plugin for producing messages and sending them
734 <https://github.com/edenhill/librdkafka>
736 * librouteros (optional)
737 Used by the `routeros' plugin to connect to a device running `RouterOS'.
738 <http://octo.it/librouteros/>
741 Used by the `rrdtool' and `rrdcached' plugins. The latter requires RRDtool
742 client support which was added after version 1.3 of RRDtool. Versions 1.0,
743 1.2 and 1.3 are known to work with the `rrdtool' plugin.
744 <http://oss.oetiker.ch/rrdtool/>
746 * librt, libsocket, libkstat, libdevinfo (optional)
747 Various standard Solaris libraries which provide system functions.
748 <http://developers.sun.com/solaris/>
750 * libsensors (optional)
751 To read from `lm_sensors', see the `sensors' plugin.
752 <http://www.lm-sensors.org/>
754 * libsigrok (optional)
755 Used by the `sigrok' plugin. In addition, libsigrok depends on glib,
756 libzip, and optionally (depending on which drivers are enabled) on
757 libusb, libftdi and libudev.
759 * libstatgrab (optional)
760 Used by various plugins to collect statistics on systems other than Linux
762 <http://www.i-scream.org/libstatgrab/>
764 * libtokyotyrant (optional)
765 Used by the `tokyotyrant' plugin.
766 <http://1978th.net/tokyotyrant/>
768 * libupsclient/nut (optional)
769 For the `nut' plugin which queries nut's `upsd'.
770 <http://networkupstools.org/>
773 Collect statistics from virtual machines.
774 <http://libvirt.org/>
777 Parse XML data. This is needed for the `ascent', `bind', `curl_xml' and
779 <http://xmlsoft.org/>
782 <http://www.xmms.org/>
785 Parse JSON data. This is needed for the `curl_json' and `log_logstash'
787 <http://github.com/lloyd/yajl>
789 * libvarnish (optional)
790 Fetches statistics from a Varnish instance. This is needed for the
792 <http://varnish-cache.org>
794 Configuring / Compiling / Installing
795 ------------------------------------
797 To configure, build and install collectd with the default settings, run
798 `./configure && make && make install'. For detailed, generic instructions
799 see INSTALL. For a complete list of configure options and their description,
800 run `./configure --help'.
802 By default, the configure script will check for all build dependencies and
803 disable all plugins whose requirements cannot be fulfilled (any other plugin
804 will be enabled). To enable a plugin, install missing dependencies (see
805 section `Prerequisites' above) and rerun `configure'. If you specify the
806 `--enable-<plugin>' configure option, the script will fail if the depen-
807 dencies for the specified plugin are not met. In that case you can force the
808 plugin to be built using the `--enable-<plugin>=force' configure option.
809 This will most likely fail though unless you're working in a very unusual
810 setup and you really know what you're doing. If you specify the
811 `--disable-<plugin>' configure option, the plugin will not be built. If you
812 specify the `--enable-all-plugins' or `--disable-all-plugins' configure
813 options, all plugins will be enabled or disabled respectively by default.
814 Explicitly enabling or disabling a plugin overwrites the default for the
815 specified plugin. These options are meant for package maintainers and should
816 not be used in everyday situations.
818 By default, collectd will be installed into `/opt/collectd'. You can adjust
819 this setting by specifying the `--prefix' configure option - see INSTALL for
820 details. If you pass DESTDIR=<path> to `make install', <path> will be
821 prefixed to all installation directories. This might be useful when creating
822 packages for collectd.
824 Configuring with libjvm
825 -----------------------
827 To determine the location of the required files of a Java installation is not
828 an easy task, because the locations vary with your kernel (Linux, SunOS, …)
829 and with your architecture (x86, SPARC, …) and there is no ‘java-config’
830 script we could use. Configuration of the JVM library is therefore a bit
833 The easiest way to use the `--with-java=$JAVA_HOME' option, where
834 `$JAVA_HOME' is usually something like:
835 /usr/lib/jvm/java-1.5.0-sun-1.5.0.14
837 The configure script will then use find(1) to look for the following files:
843 If found, appropriate CPP-flags and LD-flags are set and the following
844 library checks succeed.
846 If this doesn't work for you, you have the possibility to specify CPP-flags,
847 C-flags and LD-flags for the ‘Java’ plugin by hand, using the following three
848 (environment) variables:
854 For example (shortened for demonstration purposes):
856 ./configure JAVA_CPPFLAGS="-I$JAVA_HOME/include -I$JAVA_HOME/include/linux"
858 Adding "-ljvm" to the JAVA_LDFLAGS is done automatically, you don't have to
864 To compile correctly collectd needs to be able to initialize static
865 variables to NAN (Not A Number). Some C libraries, especially the GNU
866 libc, have a problem with that.
868 Luckily, with GCC it's possible to work around that problem: One can define
869 NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
870 ``implementation'' the configure script needs to compile and run a short
871 test program. Obviously running a test program when doing a cross-
872 compilation is, well, challenging.
874 If you run into this problem, you can use the `--with-nan-emulation'
875 configure option to force the use of this implementation. We can't promise
876 that the compiled binary actually behaves as it should, but since NANs
877 are likely never passed to the libm you have a good chance to be lucky.
879 Likewise, collectd needs to know the layout of doubles in memory, in order
880 to craft uniform network packets over different architectures. For this, it
881 needs to know how to convert doubles into the memory layout used by x86. The
882 configure script tries to figure this out by compiling and running a few
883 small test programs. This is of course not possible when cross-compiling.
884 You can use the `--with-fp-layout' option to tell the configure script which
885 conversion method to assume. Valid arguments are:
887 * `nothing' (12345678 -> 12345678)
888 * `endianflip' (12345678 -> 87654321)
889 * `intswap' (12345678 -> 56781234)
895 For questions, bug reports, development information and basically all other
896 concerns please send an email to collectd's mailing list at
897 <list at collectd.org>.
899 For live discussion and more personal contact visit us in IRC, we're in
900 channel #collectd on freenode.
906 Florian octo Forster <octo at collectd.org>,
907 Sebastian tokkee Harl <sh at tokkee.org>,
908 and many contributors (see `AUTHORS').
910 Please send bug reports and patches to the mailing list, see `Contact'
projects / collectd.git / blob