# How to Open a file which is in the memory by H5Pset\_fapl\_core? **URL:** \ **Category:** Hdf-forum archives\ **Created:** [June 21, 2013, 1:20am UTC](https://forum.hdfgroup.org/t/how-to-open-a-file-which-is-in-the-memory-by-h5pset-fapl-core/2935 "2013-06-21T01:20:35Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![long](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/l/e47774/32.png) [@long](https://forum.hdfgroup.org/u/long)\ **Post date:** [June 21, 2013, 1:20am UTC](https://forum.hdfgroup.org/t/how-to-open-a-file-which-is-in-the-memory-by-h5pset-fapl-core/2935/1 "2013-06-21T01:20:35Z")
I could create a simple file in memory by \*fapl = H5Pcreate(H5P\_FILE\_ACCESS);\* \*H5Pset\_fapl\_core(fapl,1024,0);\* \*file = H5Fcreate(H5FILE\_NAME, H5F\_ACC\_TRUNC, H5P\_DEFAULT, fapl);\* And I want to use H5Fopen to get this file in memory. \*file = H5Fopen(H5FILE\_NAME, H5F\_ACC\_RDWR, fapl);\* > **···** > > \* > \* > But I failed. > The error is: > \*HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0:\* > \* #000: H5F.c line 1582 in H5Fopen(): unable to open file\* > \* major: File accessibilty\* > \* minor: Unable to open file\* > \* #001: H5F.c line 1271 in H5F\_open(): unable to open file: time = Fri Jun > 21 03:19:11 2013\* > \*, name = 'Driver\_test5.h5', tent\_flags = 1\* > \* major: File accessibilty\* > \* minor: Unable to open file\* > \* #002: H5FD.c line 987 in H5FD\_open(): open failed\* > \* major: Virtual File Layer\* > \* minor: Unable to initialize object\* > \* #003: H5FDcore.c line 441 in H5FD\_core\_open(): unable to open file\* > \* major: File accessibilty\* > \* minor: Unable to open file\* > > The document said :The H5FD\_CORE driver enables an application to work with > a file in memory, speeding reads and writes as no disk access is made. > > How to fix it and What should I do? > > Thanks ---
**Author:** ![Quincey\_Koziol](https://forum.hdfgroup.org/letter_avatar_proxy/v4/letter/q/dbc845/32.png) [@Quincey\_Koziol](https://forum.hdfgroup.org/u/Quincey_Koziol)\ **Post date:** [June 27, 2013, 3:25pm UTC](https://forum.hdfgroup.org/t/how-to-open-a-file-which-is-in-the-memory-by-h5pset-fapl-core/2935/2 "2013-06-27T15:25:11Z")
Hi Long, > I could create a simple file in memory by > > fapl = H5Pcreate(H5P\_FILE\_ACCESS); > H5Pset\_fapl\_core(fapl,1024,0); > file = H5Fcreate(H5FILE\_NAME, H5F\_ACC\_TRUNC, H5P\_DEFAULT, fapl); > > And I want to use H5Fopen to get this file in memory. > file = H5Fopen(H5FILE\_NAME, H5F\_ACC\_RDWR, fapl); > > But I failed. > The error is: > HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0: >   #000: H5F.c line 1582 in H5Fopen(): unable to open file >     major: File accessibilty >     minor: Unable to open file >   #001: H5F.c line 1271 in H5F\_open(): unable to open file: time = Fri Jun 21 03:19:11 2013 > , name = 'Driver\_test5.h5', tent\_flags = 1 >     major: File accessibilty >     minor: Unable to open file >   #002: H5FD.c line 987 in H5FD\_open(): open failed >     major: Virtual File Layer >     minor: Unable to initialize object >   #003: H5FDcore.c line 441 in H5FD\_core\_open(): unable to open file >     major: File accessibilty >     minor: Unable to open file > > The document said :The H5FD\_CORE driver enables an application to work with a file in memory, speeding reads and writes as no disk access is made. > > How to fix it and What should I do?   Try using the "file image" routines: H5Pset\_file\_image H5Pget\_file\_image H5Pset\_file\_image\_callbacks H5Pget\_file\_image\_callbacks   [http://www.hdfgroup.org/HDF5/doc/RM/RM\_H5P.html](http://www.hdfgroup.org/HDF5/doc/RM/RM_H5P.html)     Quincey > **···** > > On Jun 20, 2013, at 8:20 PM, long zhao \ wrote: