Error when opening compound reader for Directory and – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-7.12

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Briefly, this error occurs when Elasticsearch is unable to open a compound file system (CFS) reader for a specific directory. This could be due to a corrupted index, insufficient permissions, or disk space issues. To resolve this, you can try the following: 1) Check and repair the corrupted index, 2) Ensure Elasticsearch has the necessary permissions to access the directory, 3) Free up or increase disk space, 4) If the error persists, consider reindexing your data.

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This guide will help you check for common problems that cause the log ” Error when opening compound reader for Directory [{}] and ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index.

Log Context

Log “Error when opening compound reader for Directory [{}] and ” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

        if (useCompoundFile) {
            try {
                directory = engineConfig.getCodec().compoundFormat().getCompoundReader(;
          ; IOContext.READ);
            } catch (IOException e) {
                logger.warn(() -> new ParameterizedMessage("Error when opening compound reader for Directory [{}] and " +
                    "SegmentCommitInfo [{}]";; segmentCommitInfo); e);

                return ImmutableOpenMap.of();
        } else {


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