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problem in editing swift_hash_path_suffix

asked 2013-08-24 02:28:36 -0500

pragya jain gravatar image

updated 2013-08-26 00:07:56 -0500

fifieldt gravatar image

I am installing and configuring swift following the steps given in the book "Software defined storage with OpenStack Swift" by Joe Arnold.

According to book, I have to configure proxy server. For this, I have to edit /etc/swift/swift.conf and change the swift_hash_path_suffix to something secret and then, start the proxy server process

for this, I use the following commands:

root@arun-Aspire-5742:~# vi /etc/swift/swift.conf

with this command, swift.conf file is opened:


# swift_hash_path_suffix and swift_hash_path_prefix are used as part of the
# the hashing algorithm when determining data placement in the cluster.
# These values should remain secret and MUST NOT change
# once a cluster has been deployed.

swift_hash_path_suffix = changeme
swift_hash_path_prefix = changeme

# The swift-constraints section sets the basic constraints on data
# saved in the swift cluster.


# max_file_size is the largest "normal" object that can be saved in
# the cluster. This is also the limit on the size of each segment of
# a "large" object when using the large object manifest support.
# This value is set in bytes. Setting it to lower than 1MiB will cause
# some tests to fail. It is STRONGLY recommended to leave this value at
# the default (5 * 2**30 + 2).

#max_file_size = 5368709122

# max_meta_name_length is the max number of bytes in the utf8 encoding
# of the name portion of a metadata header.

#max_meta_name_length = 128

# max_meta_value_length is the max number of bytes in the utf8 encoding
# of a metadata value

#max_meta_value_length = 256

# max_meta_count is the max number of metadata keys that can be stored
# on a single account, container, or object

but, I am not able to change the value of swift_hash_path_suffix. Please help me in this regard.

and also Is it necessary to change the value of swift_hash_path_prefix?

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answered 2013-08-24 03:13:03 -0500

fifieldt gravatar image


It is necessary to change swift_hash_path_prefix - for the security reasons stated in the book.

The note in the configuration file saying: "These values should remain secret and MUST NOT change" applies _after_ you have set up the cluster for the first time.

You may edit this file in any editor, you don't have to use vim. If you need assistance using vim, there are many good tutorials online.

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answered 2013-08-24 06:53:21 -0500

blazesurfer gravatar image

i found that if i set the prefix and then keep a copy of the swift.conf file saved offline to the box iv got the key in an emergency

the easiest way if using a bare-bone Linux system i find is to

vi /etc/swift/

then press the "i" key to enter insert mode edit the line needed

press "esc" key type "wq!"

this saves and closes the file.

then restart or start swift-init main start or restart.

if you have every thing else setup

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Asked: 2013-08-24 02:28:36 -0500

Seen: 1,213 times

Last updated: Aug 24 '13