dcache
dcache is a versatile storage management system. With lots of extentions. You can store your files on disk and tape.
command reference
Show what port which dcache service is using
dcache ports
start all dcache services
systemctl start dcache.target
show dcache services on host
systemctl list-units -q dcache@*.service
pool commands
create new pool. Poolname 'pool1' part of domain: 'dCacheDomain'. Mountpoint where files and metadata are stored: /srv/dcache/pool-1
dcache pool create /srv/dcache/pool-1 pool1 dCacheDomain
file interactions
upload file through webdav door and simple authentication
curl -u tester:secret -l -t da_file http://localhost:2880/home/tester/da_file
http://localhost:2882 can also be viewed in the browser to get a simple webinterface for browsing files
admin interface
Login to dcache admin interface
ssh -p 22224 admin@localhost
show help of admin shell metacommand
\? \c
list cells
\l
connect to specific cell
\c PnfsManager
show filename and path of a pnfsid
Connect to the PnfsManager via admin interface and issue the following command
[localhost] (PnfsManager@dCacheDomain) admin > pathfinder 0000417C62828C1A47E9A5C321991E8D260D
/home/tester/tape/PXL_20250810_084619675.MP.jpg
get the pnfsid of a file
Connect to the PnfsManager and issue the following command
[localhost] (PnfsManager@dCacheDomain) admin > pnfsidof /home/tester/tape/PXL_20250810_084619675.MP.jpg
0000417C62828C1A47E9A5C321991E8D260D
Requesting a accesstoken
Most dCache instances are part of something called the EU GRID. And most of these support token authentication.
git clone https://github.com/sara-nl/GridScripts.git
cd GridScripts
./get-macaroon --url https://your-dcache-address.com:443/data/users/you_username --duration P7D --chroot --user you_username --permissions DOWNLOAD,UPLOAD,DELETE,MANAGE,LIST,READ_METADATA,UPDATE_METADATA,STAGE --output rclone tokenfile
--duration P7D: duration that the token is valid. In this case 7 days.
--chroot: changeroot the user to the path defined in the url. In this case: /data/users/you_username
--user: the user for which the token should be created
--permissions: which persmissions should the user get in dCache.
--output: Which output type should be used and what should be the filename. In this case: output format rclone and name tokenfile.conf
Now cat your tokenfile to find your bearer_token
grep bearer_token tokenfile.conf
api interface
when accessing a api door. you can look at a swagger interface to see all api calls you can make. This swagger ui makes it easy to try out different calls and will show the curl command you can use to replicate it form the commandline.
https://127.0.0.1:443/api/v1/
cancel bulk-request
You can cancel a bulk-request using the requestID you got back from creating the bulk-request. You can either send a DELETE request or PATCH request. Here's an example on how to use the PATCH request method to cancel a bulk-request.
curl -i -H "Authorization: bearer $BEARER_TOKEN" -X PATCH "https://127.0.0.1/api/v1/bulk-requests/98fb3f62-a36f-275f-9abe-e1b461f5df32" -H "accept: application/json" -H "Content-Type: application/json" -d '{"action":"cancel"}'
dcache configuration file
Enable logging for multiple components.
When you want to enable lots of logs, add the following to you /etc/dcache/dcache.conf
dcache.log.level.file=debug
dcache.log.level.pinboard=warn
dcache.log.level.remote=warn
dcache.log.level.events=warn
dcache.log.level.access=warn
dcache.log.level.zookeeper=warn
create a python interface to getting all the current properties from dCache
dcache loader -q compile -python
Check with service runs in which Domain
[root@localhost dcache]# dcache services
DOMAIN SERVICE CELL PROXIED REPLICABLE
dCacheDomain zookeeper zookeeper - No
dCacheDomain admin admin - No
dCacheDomain pnfsmanager PnfsManager - Yes
dCacheDomain poolmanager PoolManager - Yes
dCacheDomain pinmanager PinManager - Yes
dCacheDomain billing billing - Yes
dCacheDomain cleaner-disk cleaner-disk - Yes
dCacheDomain gplazma gPlazma - Yes
dCacheDomain webdav WebDAV-localhost No No
dCacheDomain frontend Frontend-localhost No No
dCacheDomain bulk bulk - Yes
pool1Domain pool pool1 - No
tapePool1 pool tapepool1 - No
Add a very simple test hsm script for staging and unstaging files
or use the builtin provider copy
hsm create -command=/bin/cp -store=/hsmstor -retrieve=/hsmstor osm copy
upload a file to dcache using the webdav door and curl
curl -k -v -u username:password -L -T PXL_20250810_084341496.MP.jpg https://192.168.122.16:2880/home/tester/tape/PXL_20250810_084341496.MP.jpg
bulk stage files
curl -u username:password -L -H 'accept: application/json' --fail --show-error --ipv4 -H 'content-type: application/json' -X POST http://192.168.122.16:20443/api/v1/bulk-requests -d '{"activity": "PIN", "arguments": {"lifetime": "7", "lifetimeUnit":"DAYS"}, "target": ["/home/tester"], "expand_directories": "TARGETS"}'
delete stage request
curl -k -u username:password -X DELETE "https://192.168.122.16:3880/api/v1/bulk-requests/98242567-b3f9-40b4-a452-60f66f3224be?cancelIfRunning=true" -H "accept: application/json"
some example settings without further explanation
chimera commands
chimera mkdir /home/tester/tape
chimera chown 1000:1000 /home/tester/tape
chimera writetag /home/tester/tape hsmType osm
chimera writetag /home/tester/tape OSMTemplate 'StoreName generic'
chimera writetag /home/tester/tape sGroup tape
chimera writetag /home/tester/tape AccessLatency NEARLINE
chimera writetag /home/tester/tape RetentionPolicy CUSTODIAL
Pool Selection Unit (PSU) settings
psu set regex off
psu set allpoolsactive on
psu create unit -store *@*
psu create unit -store generic:tape@osm
psu create unit -net 0.0.0.0/0.0.0.0
psu create unit -net ::/0
psu create unit -protocol */*
psu create ugroup any-protocol
psu addto ugroup any-protocol */*
psu create ugroup any-store
psu addto ugroup any-store *@*
psu create ugroup tape-ugroup
psu addto ugroup tape-ugroup generic:tape@osm
psu create ugroup world-net
psu addto ugroup world-net 0.0.0.0/0.0.0.0
psu addto ugroup world-net ::/0
psu create pool pool1
psu create pool tapepool1
psu create pgroup default
psu addto pgroup default pool1
psu create pgroup tape-pools
psu addto pgroup tape-pools tapepool1
psu create link default-link any-protocol any-store world-net
psu set link default-link -readpref=10 -writepref=10 -cachepref=10 -p2ppref=-1
psu addto link default-link default
psu create link tape-link any-protocol tape-ugroup world-net
psu set link tape-link -readpref=10 -writepref=10 -cachepref=10 -p2ppref=-1
psu addto link tape-link tape-pools