Metapartitions
Andrew, Could you just exlplain to me the metapartition ? What info is kept there and which is there regular location ? metapartition-p1: /var/spool/cyrus/mail/meta1 metapartition_files: index cache expunge squat Thanks D. Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
Re: Metapartitions
Diego, Diego Ventrice schrieb: Andrew, Could you just exlplain to me the metapartition ? Don't you want answers from anyone else? ;) What info is kept there and which is there regular location ? metapartition-p1: /var/spool/cyrus/mail/meta1 metapartition_files: index cache expunge squat So, you found the metapartition_files directive and still want to know what it does? metapartition_files: empty string Space-separated list of metadata files to be stored on a metapartition rather than in the mailbox directory on a spool partition. Allowed values: header, index, cache, expunge, squat metapartition-name: none The pathname of the metadata partition name, corresponding to spool partition partition-name. For any mailbox residing in a directory on partition-name, the metadata files listed in metapartition_files will be stored in a corresponding directory on metapartition-name. Note that not every partition-name option is required to have a corresponding metapartition-name option, so that you can selectively choose which spool partitions will have separate metadata partitions. [man imapd.conf] What do you think files named header, index, cache, expunge and squat in this context contain? ;) Marc Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
Re: Metapartitions
Danke Marc, clearer now. And sure, I'll take answers from anyone. About this: What do you think files named header, index, cache, expunge and squat in this context contain? ;) Ich denke this are the cyrus header index and cache files generally stored on each mailbox folder. I can imagine what they do but not sure and I wouldnt mind about a little explanation =) About expunge and squat, keine Idee about what they are for and where they reside expunge: index file with messages marked for deletion ? Thanks again D. Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
Re: Metapartitions
Hi, Quoting Diego Ventrice fordcar...@googlemail.com: Danke Marc, clearer now. And sure, I'll take answers from anyone. About this: What do you think files named header, index, cache, expunge and squat in this context contain? ;) Ich denke this are the cyrus header index and cache files generally stored on each mailbox folder. I can imagine what they do but not sure and I wouldnt mind about a little explanation =) most of the time cyrus does not need to access the message file (.) but uses the cyrus.* files. These files are small compared to the sum of the message files. By defining a metapartition you can use fast but expensiv storage like SSDs for the metadata and other storage for the mails. About expunge and squat, keine Idee about what they are for and where they reside expunge: index file with messages marked for deletion ? Thanks again D. Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html M.MengeTel.: (49) 7071/29-70316 Universität Tübingen Fax.: (49) 7071/29-5912 Zentrum für Datenverarbeitung mail: michael.me...@zdv.uni-tuebingen.de Wächterstraße 76 72074 Tübingen smime.p7s Description: S/MIME Signatur Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
Re: Metapartitions
On 17/03/10 14:45 -0300, Diego Ventrice wrote: Danke Marc, clearer now. And sure, I'll take answers from anyone. About this: What do you think files named header, index, cache, expunge and squat in this context contain? ;) Ich denke this are the cyrus header index and cache files generally stored on each mailbox folder. I can imagine what they do but not sure and I wouldnt mind about a little explanation =) About expunge and squat, keine Idee about what they are for and where they reside expunge: index file with messages marked for deletion ? http://cyrusimap.web.cmu.edu/imapd/internal/mailbox-format.html -- Dan White Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
Re: Metapartitions
Thanks Mark, Thats what I guessed. I suppose these files make use of the .seen and .sub files under also, right ? Diego And thanks Dan for the link. http://cyrusimap.web.cmu.edu/imapd/internal/mailbox-format.html -- Dan White Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
Re: Metapartitions
On Wed, Mar 17, 2010 at 09:17:49PM -0300, Diego Ventrice wrote: Thanks Mark, Thats what I guessed. I suppose these files make use of the .seen and .sub files under also, right ? .seen and .sub files are always in your configdir - where the mailboxes.db and related things are. It's actually not quite flexible enough for my liking, and I'm seriously considering a per-file configuration option that will allow things like deliver.db and statuscache.db to be configured on different paths - specifically on tmpfs! We already symlink the proc directory out to tmpfs, but that's harder to do with individual files. ... but that's debate for the future: for now there are basically three locations of interest: 1) the data path, where emails are stored 2) the (optional) metadata path, where you can choose to locate some higher IO rate small files 3) the config directory. In our experience, the size of (2 + 3) with all cyrus.* files except squat on meta is about 5% (20/1) of data. The IO rates around 5/1 meta over data. That makes it a pretty good tradeoff to split the meta onto small fast storage. My rough testing a little while back showed about a 50% split between 2 and 3. So half the IO is to the config directory (databases + .seen and quota files) and half is to cyrus.index and cyrus.cache files. This is on machines with lots of memory, so the majority of hot data is in memory - most of the ongoing IO is writes. Bron. Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
