---
layout: manual
Content-Style: 'text/css'
title: _MP(PMEMBLK_SET_ZERO, 3)
collection: libpmemblk
header: PMDK
date: pmemblk API version 1.1
...

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[comment]: <> (pmemblk_set_zero.3 -- man page for block management functions)


[NAME](#name)<br />
[SYNOPSIS](#synopsis)<br />
[DESCRIPTION](#description)<br />
[RETURN VALUE](#return-value)<br />
[SEE ALSO](#see-also)<br />


# NAME #

**pmemblk_set_zero**(), **pmemblk_set_error**() --  block management functions


# SYNOPSIS #

```c
#include <libpmemblk.h>

int pmemblk_set_zero(PMEMblkpool *pbp, long long blockno);
int pmemblk_set_error(PMEMblkpool *pbp, long long blockno);
```


# DESCRIPTION #

The **pmemblk_set_zero**() function writes zeros to block number *blockno* in
persistent memory resident array of blocks *pbp*. Using this function is faster
than actually writing a block of zeros since **libpmemblk**(7) uses metadata to
indicate the block should read back as zero.

The **pmemblk_set_error**() function sets the error state for block number
*blockno* in persistent memory resident array of blocks *pbp*.
A block in the error state returns *errno* **EIO** when read.
Writing the block clears the error state and returns the block to normal use.

# RETURN VALUE #

On success,  **pmemblk_set_zero**() and **pmemblk_set_error**() return 0.
On error, they return -1 and set *errno* appropriately.


# SEE ALSO #

**libpmemblk**(7) and **<http://pmem.io>**
