# Documentation bug on splitting shards -- free disk space requirement?
**URL:** https://discuss.elastic.co/t/documentation-bug-on-splitting-shards-free-disk-space-requirement/367203
**Category:** Elasticsearch
**Created:** [September 26, 2024, 9:16pm UTC](https://discuss.elastic.co/t/documentation-bug-on-splitting-shards-free-disk-space-requirement/367203 "2024-09-26T21:16:34Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Jamshid](https://discuss.elastic.co/u/Jamshid)
#### Post date: [September 26, 2024, 9:16pm UTC](https://discuss.elastic.co/t/documentation-bug-on-splitting-shards-free-disk-space-requirement/367203/1 "2024-09-26T21:16:34Z")
This doc says elasticsearch requires enough free disk space for a second copy of the index when splitting shards.
> **[Split index API | Elasticsearch Guide \[8.15\] | Elastic](https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-split-index.html)**
> - The node handling the split process must have sufficient free disk space to accommodate a second copy of the existing index.
But this discussion seems to indicate that it depends on how many shards are being created. When splitting a 5 shard index to 20 shards it requires **4x** the disk space, right?
> [@Cloned/Split Indexes Take Double Disk Space When Increasing Shards](https://discuss.elastic.co/t/cloned-split-indexes-take-double-disk-space-when-increasing-shards/254342):
>
> Currently I have some large index's (100GB - 500GB) that have been allocated 5 shards. I would like to increase these to 10 - 20 shards each. If I use the Split API or Clone API it takes 1-2 minutes for the new index to be created, but the disk space doubles if I set it to 10 shards, and quadruples if I set it to 20 shards. (Replicas are still 0). Is there a way to reduce the disk space? The document counts are the same, Im guessing it has to do with how it links to the physical files at th…
Should I file a github issue to get the documentation fixed? Or am I misunderstanding, maybe the hard links splitting creates makes it seem like it's using more space than it really is?
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### Author:  [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)
#### Post date: [September 27, 2024, 9:11am UTC](https://discuss.elastic.co/t/documentation-bug-on-splitting-shards-free-disk-space-requirement/367203/2 "2024-09-27T09:11:48Z")
> [@Jamshid](#):
>
> Or am I misunderstanding, maybe the hard links splitting creates makes it seem like it's using more space than it really is?
Yeah I think you're misunderstanding. The total size of all the shards will indeed go up by a large amount, but this metric double-counts any files that are hard-linked between shards. The actual disk space needed should only be approximately 2x the size of the original shards.
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### Author:  [@Jamshid](https://discuss.elastic.co/u/Jamshid)
#### Post date: [October 10, 2024, 9:12pm UTC](https://discuss.elastic.co/t/documentation-bug-on-splitting-shards-free-disk-space-requirement/367203/3 "2024-10-10T21:12:17Z")
Thanks David. To be clear, splitting shards from 5 =\> 20 does not even _temporarily_ require 4x the disk space?
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### Author:  [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)
#### Post date: [October 11, 2024, 2:50am UTC](https://discuss.elastic.co/t/documentation-bug-on-splitting-shards-free-disk-space-requirement/367203/4 "2024-10-11T02:50:06Z")
Correct