# PS 8.0.27: Wrong Free buffers value?

**URL:** https://forums.percona.com/t/ps-8-0-27-wrong-free-buffers-value/15301
**Category:** Percona Distribution for MySQL
**Created:** [April 19, 2022, 4:51pm UTC](https://forums.percona.com/t/ps-8-0-27-wrong-free-buffers-value/15301 "2022-04-19T16:51:10Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Oleksandr\_Bezpiatov](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/oleksandr_bezpiatov/32/4451_2.png) [@Oleksandr\_Bezpiatov](https://forums.percona.com/u/Oleksandr_Bezpiatov)
#### Post date: [April 19, 2022, 4:51pm UTC](https://forums.percona.com/t/ps-8-0-27-wrong-free-buffers-value/15301/1 "2022-04-19T16:51:10Z")

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Hi all,

Quick question.

I’ve raised innodb\_lru\_scan\_depth variable value up to 8192 (don’t ask why, experiments) to see how it can impact multithreaded dump import performance.

But since I started this import, and done this command:  
`mysql -e "show engine innodb status\G" | grep 'Free buffers'`

I see next values:

```auto
Free buffers 136889
Free buffers 138022
Free buffers 137668
Free buffers 137161
Free buffers 137576
Free buffers 137258
Free buffers 137462
Free buffers 138242
Free buffers 137385
Free buffers 137131
Free buffers 137923
Free buffers 138432
Free buffers 137883
Free buffers 137830
Free buffers 137752
Free buffers 137879
Free buffers 137419
Free buffers 137561
Free buffers 137180
Free buffers 137457
Free buffers 138534
Free buffers 137592
Free buffers 138085
Free buffers 137498
Free buffers 137072
Free buffers 138296
Free buffers 137379
Free buffers 137319
Free buffers 137459
Free buffers 137787

```

What is wrong? From what I understand it should be equal maximum to `innodb_lru_scan_depth` value?

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<div class="post-metadata">

### Author: ![matthewb](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/matthewb/32/34_2.png) [@matthewb](https://forums.percona.com/u/matthewb)
#### Post date: [April 19, 2022, 5:21pm UTC](https://forums.percona.com/t/ps-8-0-27-wrong-free-buffers-value/15301/2 "2022-04-19T17:21:10Z")

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`innodb_lru_scan_depth` “… influences the algorithms and heuristics for the flush operation for the buffer pool. … It specifies, per buffer pool instance, how far down the buffer pool LRU page list the page cleaner thread scans looking for dirty pages to flush.”

“Free buffers” is the number of pages in your buffer pool that are free to hold new data. The two are not directly related.

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<div class="post-metadata">

### Author: ![Oleksandr\_Bezpiatov](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/oleksandr_bezpiatov/32/4451_2.png) [@Oleksandr\_Bezpiatov](https://forums.percona.com/u/Oleksandr_Bezpiatov)
#### Post date: [April 19, 2022, 6:48pm UTC](https://forums.percona.com/t/ps-8-0-27-wrong-free-buffers-value/15301/3 "2022-04-19T18:48:51Z")

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Ah. Now clear. Sorry for such lame question.

Topic is closed.