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| author | Ingo Molnar <mingo@elte.hu> | 2010-10-30 12:43:08 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-10-30 12:43:08 +0400 |
| commit | 169ed55bd30305b933f52bfab32a58671d44ab68 (patch) | |
| tree | 32e280957474f458901abfce16fa2a1687ef7497 /Documentation/scsi/st.txt | |
| parent | 3d7851b3cdd43a734e5cc4c643fd886ab28ad4d5 (diff) | |
| parent | 45f81b1c96d9793e47ce925d257ea693ce0b193e (diff) | |
| download | linux-169ed55bd30305b933f52bfab32a58671d44ab68.tar.xz | |
Merge branch 'tip/perf/jump-label-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
Diffstat (limited to 'Documentation/scsi/st.txt')
| -rw-r--r-- | Documentation/scsi/st.txt | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt index 40752602c050..691ca292c24d 100644 --- a/Documentation/scsi/st.txt +++ b/Documentation/scsi/st.txt @@ -2,7 +2,7 @@ This file contains brief information about the SCSI tape driver. The driver is currently maintained by Kai Mäkisara (email Kai.Makisara@kolumbus.fi) -Last modified: Sun Feb 24 21:59:07 2008 by kai.makisara +Last modified: Sun Aug 29 18:25:47 2010 by kai.makisara BASICS @@ -85,6 +85,17 @@ writing and the last operation has been a write. Two filemarks can be optionally written. In both cases end of data is signified by returning zero bytes for two consecutive reads. +Writing filemarks without the immediate bit set in the SCSI command block acts +as a synchronization point, i.e., all remaining data form the drive buffers is +written to tape before the command returns. This makes sure that write errors +are caught at that point, but this takes time. In some applications, several +consecutive files must be written fast. The MTWEOFI operation can be used to +write the filemarks without flushing the drive buffer. Writing filemark at +close() is always flushing the drive buffers. However, if the previous +operation is MTWEOFI, close() does not write a filemark. This can be used if +the program wants to close/open the tape device between files and wants to +skip waiting. + If rewind, offline, bsf, or seek is done and previous tape operation was write, a filemark is written before moving tape. @@ -301,6 +312,8 @@ MTBSR Space backward over count records. MTFSS Space forward over count setmarks. MTBSS Space backward over count setmarks. MTWEOF Write count filemarks. +MTWEOFI Write count filemarks with immediate bit set (i.e., does not + wait until data is on tape) MTWSM Write count setmarks. MTREW Rewind tape. MTOFFL Set device off line (often rewind plus eject). |