gistfile1.txt

swift@saio-1:~/swift$ ls /mnt/sdb1/2/node/sdb2/objects/67/df9/10d5773cd70408b48b48246de59f7df9/
1425992084.29355.data

swift@saio-1:~/swift$ python ./anc/metawriter.py /mnt/sdb1/2/node/sdb2/objects/67/df9/10d5773cd70408b48b48246de59f7df9/ '{"X-Object-Meta-Me": "wrote this", "X-Object-Sysmeta-Stuff": "system stuff"}'
{u'X-Object-Sysmeta-Stuff': u'system stuff', u'X-Object-Meta-Me': u'wrote this', 'X-Timestamp': '1425993014.14010', 'name': '/a/bogus/path'}

swift@saio-1:~/swift$ ls /mnt/sdb1/2/node/sdb2/objects/67/df9/10d5773cd70408b48b48246de59f7df9/1425992084.29355.data  1425993014.14010.meta

swift@saio-1:~/swift$ ./bin/swift-object-info /mnt/sdb1/2/node/sdb2/objects/67/df9/10d5773cd70408b48b48246de59f7df9/142599
1425992084.29355.data  1425993014.14010.meta  
swift@saio-1:~/swift$ ./bin/swift-object-info /mnt/sdb1/2/node/sdb2/objects/67/df9/10d5773cd70408b48b48246de59f7df9/1425993014.14010.meta 
Path: /a/bogus/path
  Account: a
  Container: bogus
  Object: path
  Object hash: cf91ca7bbda2945dd1c015f77377f748
Content-Type: Not found in metadata
Timestamp: 2015-03-10T13:10:14.140100 (1425993014.14010)
User Metadata: {u'X-Object-Sysmeta-Stuff': u'system stuff', u'X-Object-Meta-Me': u'wrote this'}
ETag: Not found in metadata
Content-Length: Not found in metadata
Partition	830
Hash     	cf91ca7bbda2945dd1c015f77377f748

Server:Port Device	127.0.0.1:6030 sdb3
Server:Port Device	127.0.0.1:6020 sdb2
Server:Port Device	127.0.0.1:6040 sdb4
Server:Port Device	127.0.0.1:6010 sdb1	 [Handoff]


curl -I -XHEAD "http://127.0.0.1:6030/sdb3/830/a/bogus/path" -H "X-Backend-Storage-Policy-Index: 0"
curl -I -XHEAD "http://127.0.0.1:6020/sdb2/830/a/bogus/path" -H "X-Backend-Storage-Policy-Index: 0"
curl -I -XHEAD "http://127.0.0.1:6040/sdb4/830/a/bogus/path" -H "X-Backend-Storage-Policy-Index: 0"
curl -I -XHEAD "http://127.0.0.1:6010/sdb1/830/a/bogus/path" -H "X-Backend-Storage-Policy-Index: 0" # [Handoff]


Use your own device location of servers:
such as "export DEVICE=/srv/node"
ssh 127.0.0.1 "ls -lah ${DEVICE:-/srv/node*}/sdb3/objects/830/748/cf91ca7bbda2945dd1c015f77377f748"
ssh 127.0.0.1 "ls -lah ${DEVICE:-/srv/node*}/sdb2/objects/830/748/cf91ca7bbda2945dd1c015f77377f748"
ssh 127.0.0.1 "ls -lah ${DEVICE:-/srv/node*}/sdb4/objects/830/748/cf91ca7bbda2945dd1c015f77377f748"
ssh 127.0.0.1 "ls -lah ${DEVICE:-/srv/node*}/sdb1/objects/830/748/cf91ca7bbda2945dd1c015f77377f748" # [Handoff]

note: `/srv/node*` is used as default value of `devices`, the real value is set in the config file on each storage node.

metawriter.py

import json
import os.path
import sys
import time

from swift.common.utils import normalize_timestamp
from swift.obj.diskfile import write_metadata, read_metadata

if __name__ == '__main__':
    args = sys.argv

    path_to_file = args[1]
    metadata = json.loads(args[2])
    ts = normalize_timestamp(time.time())
    metadata['X-Timestamp'] = ts
    metadata['name'] = '/a/bogus/path'

    filename = os.path.join(path_to_file, ts + '.meta')
    with open(filename, 'wb') as f:
        write_metadata(f, metadata)

    with open (filename, 'rb') as f:
        print read_metadata(f)