Newer
Older
# Accessing the Clusters
## Shell Access
All IT4Innovations clusters are accessed by the SSH protocol via login nodes at the address **cluster-name.it4i.cz**. The login nodes may be addressed specifically, by prepending the loginX node name to the address.
!!! note
The **cluster-name.it4i.cz** alias is currently not available through VPN connection. Use **loginX.cluster-name.it4i.cz** when connected to VPN.
### Karolina Cluster
| Login address | Port | Protocol | Login node |
| ----------------------- | ---- | -------- | ------------------------------------- |
| karolina.it4i.cz | 22 | SSH | round-robin DNS record for login[1-4] |
| login1.karolina.it4i.cz | 22 | SSH | login1 |
| login2.karolina.it4i.cz | 22 | SSH | login2 |
| login3.karolina.it4i.cz | 22 | SSH | login3 |
| login4.karolina.it4i.cz | 22 | SSH | login4 |
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
### Barbora Cluster
| Login address | Port | Protocol | Login node |
| ------------------------- | ---- | -------- | ------------------------------------- |
| barbora.it4i.cz | 22 | SSH | round-robin DNS record for login[1-2] |
| login1.barbora.it4i.cz | 22 | SSH | login1 |
| login2.barbora.it4i.cz | 22 | SSH | login2 |
### Salomon Cluster
| Login address | Port | Protocol | Login node |
| ---------------------- | ---- | -------- | ------------------------------------- |
| salomon.it4i.cz | 22 | SSH | round-robin DNS record for login[1-4] |
| login1.salomon.it4i.cz | 22 | SSH | login1 |
| login2.salomon.it4i.cz | 22 | SSH | login2 |
| login3.salomon.it4i.cz | 22 | SSH | login3 |
| login4.salomon.it4i.cz | 22 | SSH | login4 |
## Authentication
Authentication is available by [private key][1] only. Verify SSH fingerprints during the first logon:
Barbora:
```console
md5:
39:55:e2:b9:2a:a2:c4:9e:b1:8e:f0:f7:b1:66:a8:73 (RSA)
63:29:4c:3d:17:8c:be:73:4a:99:ff:83:66:ba:dd:c3 (ECDSA)
40:67:03:26:d3:6c:a0:7f:0a:df:0e:e7:a0:52:cc:4e (ED25519)
sha256:
TO5szOJf0bG7TWVLO3WABUpGKkP7nBm/RLyHmpoNpro (RSA)
lg+AaptpqFlEu5+lBecgaVdiSlYljo5+ADLItQRSYVA (ECDSA)
ZQzFTJVDdZa3I0ics9ME2qz4v5a3QzXugvyVioaH6tI (ED25519)
```
Salomon:
```console
md5:
f6:28:98:e4:f9:b2:a6:8f:f2:f4:2d:0a:09:67:69:80 (DSA)
70:01:c9:9a:5d:88:91:c7:1b:c0:84:d1:fa:4e:83:5c (RSA)
66:32:0a:ef:50:01:77:a7:52:3f:d9:f8:23:7c:2c:3a (ECDSA)
ab:3d:5e:ff:82:68:c7:72:da:4a:2d:e3:ca:85:0d:df (ED25519)
sha256:
epkqEU2eFzXnMeMMkpX02CykyWjGyLwFj528Vumpzn4 (DSA)
WNIrR7oeQDYpBYy4N2d5A6cJ2p0837S7gzzTpaDBZrc (RSA)
cYO4UdtUBYlS46GEFUB75BkgxkI6YFQvjVuFxOlRG3g (ECDSA)
bFm3stNM8ETmj8Xd7iPXNtu5X5dC2apLNXGiH3VSTuw (ED25519)
```
!!! note
SSH fingerprints are identical on all login nodes.
Private key authentication:
On **Linux** or **Mac**, use:
```console
$ ssh -i /path/to/id_rsa username@cluster-name.it4i.cz
```
If you see a warning message **UNPROTECTED PRIVATE KEY FILE!**, use this command to set lower permissions to the private key file:
```console
$ chmod 600 /path/to/id_rsa
```
On **Windows**, use the [PuTTY SSH client][2].
After logging in, you will see the command prompt:
```console
___ _____ _ _ ___ _ _
|_ _| |_ _| | || | |_ _| _ __ _ __ ___ __ __ __ _ | |_ (_) ___ _ __ ___
| | | | | || |_ | | | '_ \ | '_ \ / _ \ \ \ / / / _` | | __| | | / _ \ | '_ \ / __|
| | | | |__ _| | | | | | | | | | | | (_) | \ V / | (_| | | |_ | | | (_) | | | | | \__ \
|___| |_| |_| |___| |_| |_| |_| |_| \___/ \_/ \__,_| \__| |_| \___/ |_| |_| |___/
http://www.it4i.cz/?lang=en
Last login: Tue Jul 9 15:57:38 2013 from your-host.example.com
[username@login2.cluster-name ~]$
```
!!! note
The environment is **not** shared between login nodes, except for [shared filesystems][3].
## Data Transfer
Data in and out of the system may be transferred by SCP and SFTP protocols.
### Karolina Cluster
| Address | Port | Protocol |
| ----------------------- | ---- | --------- |
| karolina.it4i.cz | 22 | SCP, SFTP |
| login1.karolina.it4i.cz | 22 | SCP, SFTP |
| login2.karolina.it4i.cz | 22 | SCP, SFTP |
| login3.karolina.it4i.cz | 22 | SCP, SFTP |
| login4.karolina.it4i.cz | 22 | SCP, SFTP |
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
| ------------------------- | ---- | ------- |
| barbora.it4i.cz | 22 | SCP |
| login1.barbora.it4i.cz | 22 | SCP |
| login2.barbora.it4i.cz | 22 | SCP |
### Salomon Cluster
| Address | Port | Protocol |
| ---------------------- | ---- | --------- |
| salomon.it4i.cz | 22 | SCP, SFTP |
| login1.salomon.it4i.cz | 22 | SCP, SFTP |
| login2.salomon.it4i.cz | 22 | SCP, SFTP |
| login3.salomon.it4i.cz | 22 | SCP, SFTP |
| login4.salomon.it4i.cz | 22 | SCP, SFTP |
Authentication is by [private key][1] only.
!!! note
If you experience degraded data transfer performance, consult your local network provider.
On Linux or Mac, use an SCP or SFTP client to transfer data to Barbora:
```console
$ scp -i /path/to/id_rsa my-local-file username@cluster-name.it4i.cz:directory/file
```
```console
$ scp -i /path/to/id_rsa -r my-local-dir username@cluster-name.it4i.cz:directory
```
or
```console
$ sftp -o IdentityFile=/path/to/id_rsa username@cluster-name.it4i.cz
```
A very convenient way to transfer files in and out of cluster is via the fuse filesystem [SSHFS][b].
```console
$ sshfs -o IdentityFile=/path/to/id_rsa username@cluster-name.it4i.cz:. mountpoint
```
Using SSHFS, the user's Barbora home directory will be mounted on your local computer, just like an external disk.
Learn more about SSH, SCP, and SSHFS by reading the manpages:
```console
$ man ssh
$ man scp
$ man sshfs
```
On Windows, use the [WinSCP client][c] to transfer data. The [win-sshfs client][d] provides a way to mount the cluster filesystems directly as an external disc.
More information about the shared file systems is available [here][4].
## Connection Restrictions
Outgoing connections from cluster login nodes to the outside world are restricted to the following ports:
| Port | Protocol |
| ---- | -------- |
| 22 | SSH |
| 80 | HTTP |
| 443 | HTTPS |
| 873 | Rsync |
!!! note
Use **SSH port forwarding** and proxy servers to connect from cluster to all other remote ports.
Outgoing connections from cluster compute nodes are restricted to the internal network. Direct connections from compute nodes to the outside world are cut.
## Port Forwarding
### Port Forwarding From Login Nodes
!!! note
Port forwarding allows an application running on cluster to connect to arbitrary remote hosts and ports.
It works by tunneling the connection from cluster back to the user's workstations and forwarding from the workstation to the remote host.
Select an unused port on the cluster login node (for example 6000) and establish the port forwarding:
```console
$ ssh -R 6000:remote.host.com:1234 cluster-name.it4i.cz
```
In this example, we establish port forwarding between port 6000 on the cluster and port 1234 on the `remote.host.com`. By accessing `localhost:6000` on the cluster, an application will see the response of `remote.host.com:1234`. The traffic will run via the user's local workstation.
Port forwarding may be done **using PuTTY** as well. On the PuTTY Configuration screen, load your cluster configuration first. Then go to *Connection > SSH > Tunnels* to set up the port forwarding. Click the _Remote_ radio button. Insert 6000 to the _Source port_ textbox. Insert `remote.host.com:1234`. Click _Add_, then _Open_.
Port forwarding may be established directly to the remote host. However, this requires that the user has an SSH access to `remote.host.com`.
```console
$ ssh -L 6000:localhost:1234 remote.host.com
```
!!! note
Port number 6000 is chosen as an example only. Pick any free port.
### Port Forwarding From Compute Nodes
Remote port forwarding from compute nodes allows applications running on the compute nodes to access hosts outside the cluster.
First, establish the remote port forwarding from the login node, as [described above][5].
Second, invoke port forwarding from the compute node to the login node. Insert the following line into your jobscript or interactive shell:
```console
$ ssh -TN -f -L 6000:localhost:6000 login1
```
In this example, we assume that port forwarding from `login1:6000` to `remote.host.com:1234` has been established beforehand. By accessing `localhost:6000`, an application running on a compute node will see the response of `remote.host.com:1234`.
### Using Proxy Servers
Port forwarding is static; each single port is mapped to a particular port on a remote host. Connection to another remote host requires a new forward.
!!! note
Applications with inbuilt proxy support experience unlimited access to remote hosts via a single proxy server.
To establish a local proxy server on your workstation, install and run the SOCKS proxy server software. On Linux, SSHD demon provides the functionality. To establish the SOCKS proxy server listening on port 1080 run:
```console
$ ssh -D 1080 localhost
```
On Windows, install and run the free, open source Sock Puppet server.
Once the proxy server is running, establish the SSH port forwarding from cluster to the proxy server, port 1080, exactly as [described above][5]:
```console
$ ssh -R 6000:localhost:1080 cluster-name.it4i.cz
```
Now, configure the applications proxy settings to `localhost:6000`. Use port forwarding to access the [proxy server from compute nodes][5], as well.
## Graphical User Interface
* The [X Window system][6] is the principal way to get a GUI access to the clusters.
* [Virtual Network Computing][7] is a graphical desktop-sharing system that uses a Remote Frame Buffer protocol to remotely control another computer.
## VPN Access
* Access IT4Innovations internal resources via [VPN][8].
[1]: ../general/accessing-the-clusters/shell-access-and-data-transfer/ssh-keys.md
[2]: ../general/accessing-the-clusters/shell-access-and-data-transfer/putty.md
[3]: ../anselm/storage.md#shared-filesystems
[4]: ../anselm/storage.md
[5]: #port-forwarding-from-login-nodes
[6]: ../general/accessing-the-clusters/graphical-user-interface/x-window-system.md
[7]: ../general/accessing-the-clusters/graphical-user-interface/vnc.md
[8]: ../general/accessing-the-clusters/vpn-access.md
[b]: http://linux.die.net/man/1/sshfs
[c]: http://winscp.net/eng/download.php
[d]: http://code.google.com/p/win-sshfs/