EOS disk layout CGI¶
At creation time, we can inject the layout properties of a file. We do it by appending cgi parameters to the file name with xrdcp:
/eos/file_path?eos.layout.type=type&eos.layout.checksum=checksum&eos.layout.blockchecksum=block_checksum&eos.layout.nstripes=number_of_stripes&eos.layout.blocksize=block_size
Force the file to have a raid 6 layout by CGI parameters¶
Create a file in your local disk:
touch testFile
Create a directory in EOS in the default space (no layout policy is specified)
eos mkdir /eos/tmp
Copy the local file into the newly created EOS directory with the correct CGI attributes:
xrdcp -f ./testFile 'root://localhost//eos/tmp/testFile?eos.layout.type=raid6&eos.layout.checksum=adler&eos.layout.blockchecksum=crc32c&eos.layout.nstripes=10&eos.layout.blocksize=64M'
Verify that the file has 10 stripes, has a raid6 layout and that the space of each stripes is default :
EOS Console [root://localhost] |/eos/tmp/> file info testFile
File: '/eos/tmp/testFile' Flags: 0644
Size: 12
Modify: Thu Apr 23 13:58:35 2020 Timestamp: 1587643115.616137000
Change: Thu Apr 23 13:58:35 2020 Timestamp: 1587643115.446599272
Birth : Thu Apr 23 13:58:35 2020 Timestamp: 1587643115.446599272
CUid: 3 CGid: 4 Fxid: 1000356e8 Fid: 4295186152 Pid: 4294967297 Pxid: 100000001
XStype: adler XS: 1c f2 04 47 ETAGs: "1152980253317005312:1cf20447"
Layout: raid6 Stripes: 10 Blocksize: 64M LayoutId: 20670942
#Rep: 10
┌───┬──────┬────────────────────────┬────────────────┬────────────────┬──────────┬──────────────┬────────────┬────────┬────────────────────────┐
│no.│ fs-id│ host│ schedgroup│ path│ boot│ configstatus│ drain│ active│ geotag│
└───┴──────┴────────────────────────┴────────────────┴────────────────┴──────────┴──────────────┴────────────┴────────┴────────────────────────┘
0 1991 eosctafst0105.cern.ch default.0 /data1109 booted rw nodrain online flat
1 1996 eosctafst0105.cern.ch default.0 /data1114 booted rw nodrain online flat
2 1988 eosctafst0105.cern.ch default.0 /data1106 booted rw nodrain online flat
3 1994 eosctafst0105.cern.ch default.0 /data1112 booted rw nodrain online flat
4 1984 eosctafst0105.cern.ch default.0 /data1102 booted rw nodrain online flat
5 1985 eosctafst0105.cern.ch default.0 /data1103 booted rw nodrain online flat
6 1986 eosctafst0105.cern.ch default.0 /data1104 booted rw nodrain online flat
7 1992 eosctafst0105.cern.ch default.0 /data1110 booted rw nodrain online flat
8 1993 eosctafst0105.cern.ch default.0 /data1111 booted rw nodrain online flat
9 1987 eosctafst0105.cern.ch default.0 /data1105 booted rw nodrain online flat
*******
Set the space of a file at file creation¶
Create a file in your local disk:
touch testFile
Create a directory in EOS in the default space (no layout policy is specified)
eos mkdir /eos/tmp
Copy the local file into the newly created EOS directory with the correct CGI attributes:
xrdcp -f ./testFile 'root://localhost//eos/tmp/testFile?eos.space=spinners'
Verify that the file is there and is in the spinners space:
file info testFile
File: '/eos/ctaalicero/tmp/testFile' Flags: 0644
Size: 12
Modify: Thu Apr 23 14:33:37 2020 Timestamp: 1587645217.97107000
Change: Thu Apr 23 14:33:37 2020 Timestamp: 1587645217.67590452
Birth : Thu Apr 23 14:33:37 2020 Timestamp: 1587645217.67590452
CUid: 3 CGid: 4 Fxid: 1000356ec Fid: 4295186156 Pid: 4294967297 Pxid: 100000001
XStype: adler XS: 1c f2 04 47 ETAGs: "1152980254390747136:1cf20447"
Layout: plain Stripes: 1 Blocksize: 4k LayoutId: 00100002
#Rep: 1
┌───┬──────┬────────────────────────┬────────────────┬────────────────┬──────────┬──────────────┬────────────┬────────┬────────────────────────┐
│no.│ fs-id│ host│ schedgroup│ path│ boot│ configstatus│ drain│ active│ geotag│
└───┴──────┴────────────────────────┴────────────────┴────────────────┴──────────┴──────────────┴────────────┴────────┴────────────────────────┘
0 157 lxfsrd14c03.cern.ch spinners.18 /data30 booted rw nodrain online flat
*******
A remark¶
The spinner space has its layout configured as the following :
policy.blockchecksum := crc32c
policy.blocksize := 64M
policy.bloksize := 64M
policy.layout := raid6
policy.nstripes := 10
Nevertheless, the file has a layout "Plain" with one stripe. This shows that the file inherits its layout his parent directory layout configuration and not from the space policy configuration https://eos-docs.web.cern.ch/eos-docs/using/policies.html?highlight=polcies.