# Question about index.translog.disable\_flush **URL:** \ **Category:** Elasticsearch\ **Created:** [March 7, 2012, 10:38am UTC](https://discuss.elastic.co/t/question-about-index-translog-disable-flush/6930 "2012-03-07T10:38:39Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![yantsu](https://avatars.discourse-cdn.com/v4/letter/y/b5a626/32.png) [@yantsu](https://discuss.elastic.co/u/yantsu)\ **Post date:** [March 7, 2012, 10:38am UTC](https://discuss.elastic.co/t/question-about-index-translog-disable-flush/6930/1 "2012-03-07T10:38:39Z")
I'm trying to use the settings API to set index.translog.disable\_flush to true and backing up elasticsearch data afterwards. I'm using the local gateway as configured by default. Setting the disable\_flush parameter will produce a log output telling me that the option might be accepted by each index. If I start some indexing operations after that, I can see filesystem activity inside the index and translog directories of the index data. I was expecting no filesystem activity in this place with flush disabled. Does that mean, translog data are written to the filesystem even if flush is disabled? If this is the case, backing up the whole data directory may produce warnings by the backup software that files have been changed during the backup process. Such warnings could be ignored trusting elasticsearch to ignore such files during a cluster restart from backup as well. To avoid such warnings, it would be handy to have inclusion or exclusion patterns in place for backing up the data directory. Is it it possible to provide such patterns? Thanks Claas ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [March 7, 2012, 11:48am UTC](https://discuss.elastic.co/t/question-about-index-translog-disable-flush/6930/2 "2012-03-07T11:48:01Z")
Disabling flush does not mean there won't be disk activity, it just means you can copy over the data safely (technically, what happens is that it will do so without issuing a Lucene commit while you copy). On Wednesday, March 7, 2012 at 12:38 PM, yantsu wrote: > I'm trying to use the settings API to set index.translog.disable\_flush > to true and backing up elasticsearch data afterwards. > > I'm using the local gateway as configured by default. > > Setting the disable\_flush parameter will produce a log output telling > me that the option might be accepted by each index. > > If I start some indexing operations after that, I can see filesystem > activity inside the index and translog directories of the index data. > > I was expecting no filesystem activity in this place with flush > disabled. > > Does that mean, translog data are written to the filesystem even if > flush is disabled? > > If this is the case, backing up the whole data directory may produce > warnings by the backup software that files have been changed during > the backup process. Such warnings could be ignored trusting > elasticsearch to ignore such files during a cluster restart from > backup as well. > > To avoid such warnings, it would be handy to have inclusion or > exclusion patterns in place for backing up the data directory. > > Is it it possible to provide such patterns? > > Thanks > > Claas ---
**Author:** ![yantsu](https://avatars.discourse-cdn.com/v4/letter/y/b5a626/32.png) [@yantsu](https://discuss.elastic.co/u/yantsu)\ **Post date:** [March 7, 2012, 12:39pm UTC](https://discuss.elastic.co/t/question-about-index-translog-disable-flush/6930/3 "2012-03-07T12:39:15Z")
Thanks for the answer. Together with the answer in this thread ([https://groups.google.com/](https://groups.google.com/) group/elasticsearch/browse\_frm/thread/14cf8d1002a76dfe#) it brings me to the assumption that after flushing and disabling flush, it is better and save to not to put translog files in the backup. They are definitly changed through indexing operations and there is a chance they are stored in an inconsistent state in the backup. I saw more files added to the data directory during index operations and flush disabled, files with the extension like \*.fdt, \*.fdx, ..., \*.tis. Is it enough to leave out the translog files to get a consistent state in the backup or there are other files related to the translog better left out as they are taken into account during a cluster restart? Thanks Claas On 7 Mrz., 12:48, Shay Banon [kim...@gmail.com](mailto:kim...@gmail.com) wrote: > Disabling flush does not mean there won't be disk activity, it just means you can copy over the data safely (technically, what happens is that it will do so without issuing a Lucene commit while you copy). > > On Wednesday, March 7, 2012 at 12:38 PM, yantsu wrote: > > > I'm trying to use the settings API to set index.translog.disable\_flush > > to true and backing up elasticsearch data afterwards. > > > I'm using the local gateway as configured by default. > > > Setting the disable\_flush parameter will produce a log output telling > > me that the option might be accepted by each index. > > > If I start some indexing operations after that, I can see filesystem > > activity inside the index and translog directories of the index data. > > > I was expecting no filesystem activity in this place with flush > > disabled. > > > Does that mean, translog data are written to the filesystem even if > > flush is disabled? > > > If this is the case, backing up the whole data directory may produce > > warnings by the backup software that files have been changed during > > the backup process. Such warnings could be ignored trusting > > elasticsearch to ignore such files during a cluster restart from > > backup as well. > > > To avoid such warnings, it would be handy to have inclusion or > > exclusion patterns in place for backing up the data directory. > > > Is it it possible to provide such patterns? > > > Thanks > > > Claas ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [March 7, 2012, 9:07pm UTC](https://discuss.elastic.co/t/question-about-index-translog-disable-flush/6930/4 "2012-03-07T21:07:05Z")
You can copy the translog files, thats fine, but you don't have to if you issue flush before. The reason more files are created in the index location is because refreshes of the index happen regularly. Its perfectly fine to just back it while its "changing", since the "committed" (flushed) state is the one that will be recovered later on. On Wednesday, March 7, 2012 at 2:39 PM, yantsu wrote: > Thanks for the answer. > > Together with the answer in this thread ([https://groups.google.com/](https://groups.google.com/) > group/elasticsearch/browse\_frm/thread/14cf8d1002a76dfe#) > it brings me to the assumption that after flushing and disabling > flush, it is better and save to not to put translog files in the > backup. > They are definitly changed through indexing operations and there is a > chance they are stored in an inconsistent state in the backup. > I saw more files added to the data directory during index operations > and flush disabled, files with the extension like \*.fdt, \*.fdx, ..., > \*.tis. > > Is it enough to leave out the translog files to get a consistent state > in the backup or there are other files related to the translog better > left out as they are taken into account during a cluster restart? > > Thanks > > Claas > On 7 Mrz., 12:48, Shay Banon \<[kim...@gmail.com](mailto:kim...@gmail.com) ([http://gmail.com](http://gmail.com))\> wrote: > > > Disabling flush does not mean there won't be disk activity, it just means you can copy over the data safely (technically, what happens is that it will do so without issuing a Lucene commit while you copy). > > > > On Wednesday, March 7, 2012 at 12:38 PM, yantsu wrote: > > > > > I'm trying to use the settings API to set index.translog.disable\_flush > > > to true and backing up elasticsearch data afterwards. > > > > > I'm using the local gateway as configured by default. > > > > > Setting the disable\_flush parameter will produce a log output telling > > > me that the option might be accepted by each index. > > > > > If I start some indexing operations after that, I can see filesystem > > > activity inside the index and translog directories of the index data. > > > > > I was expecting no filesystem activity in this place with flush > > > disabled. > > > > > Does that mean, translog data are written to the filesystem even if > > > flush is disabled? > > > > > If this is the case, backing up the whole data directory may produce > > > warnings by the backup software that files have been changed during > > > the backup process. Such warnings could be ignored trusting > > > elasticsearch to ignore such files during a cluster restart from > > > backup as well. > > > > > To avoid such warnings, it would be handy to have inclusion or > > > exclusion patterns in place for backing up the data directory. > > > > > Is it it possible to provide such patterns? > > > > > Thanks > > > > > Claas ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 3:36am UTC](https://discuss.elastic.co/t/question-about-index-translog-disable-flush/6930/5 "2017-07-06T03:36:45Z")