search for: fsync

Btrfs had some issues with fsync()''ing directories and fsync()''ing after renames. These three new tests cover the 3 different issues we were seeing. This breaks out the dmflakey stuff into a common helper to be shared between generic/311 and generic/321. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.co...

...ting the errors and ignoring them > (seems pretty unlikely, but you never know). > > After that, it'd be down to tracing where the errors end up in the > kernel. Thanks for the tip! The results are interesting. It looks like all of mkfs's pwrite() calls succeed, but its final fsync() calls do actually fail: root@debian:~# strace mkfs.ext2 /dev/nbd0 2>&1 | tee strace.out root@debian:~# cat strace.out | grep pwrite pwrite(3, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 32768, 8187379712) = 32768 pwrite(3, "\0\0\0\0\0\0\0\0\0\0\...

Hello, We found that fsync and fdatasync syscalls sometimes don't sync data in an ext3 file system under the following conditions. 1. Kernel version is 2.6.6 or later (including 2.6.8.1 and 2.6.9-rc2). 2. Ext3's journalling mode is "data=journal". 3. Create a file (whose size is 1Mbytes) and execute umount...

Hi all, I'm using dovecot since a few months and it works great. But a few days ago some coworkers mentioned that they got errormessages in their Mailapp. I searched in the logfiles and found this: Sep 14 12:07:35 Mailserv dovecot: IMAP(eckhard-ma-domain-com): fsync(/home/eckhard-ma-domain-com/mails/.INBOX.0002-Druckangebote von Druckereien.0002-schmerk zwei_E-Mailverkehr/tmp/1189764455.P15962Q0M486676.Mailserv) failed: Input/output error Sep 14 12:07:46 Mailserv dovecot: IMAP(eckhard-ma-domain-com): fsync(/home/eckhard-ma-domain-com/mails/.INBOX.0002-Druckang...

Linux kernel (as of 2.6.15.4) has the following performance bug: Syncing (fsync() or fdatasync()) files with zero links (deleted files) in not no-op, as it should be. See details, a test C program, and the rationale in the URL below: http://b2e.ex-code.com/index.php/soft/2006/02/24/linux_performance_bug_zero_links_fsync In the article with the URL above it is also explained...

Btrfs had some issues with fsync()''ing directories and fsync()''ing after renames. These three new tests cover the 3 different issues we were seeing. This breaks out the dmflakey stuff into a common helper to be shared between generic/311 and generic/320. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.co...

Hi, I have a question on fsync() and ext3's journaling modes. Assume that I call fsync(fd) on a file. If that file is in 'data=journal' mode, would the fsync() return once the data gets safely into the journal ? On the other hand, if that file is in 'data=writeback' mode, would the fsync() return only when...

Hi all, We are building a new system which is going to use ext3 FS. We would like to know more about the behavior of ext3 in the case of failure. But before I procede, I would like to share more information about our future system. * Our application always does an fsync on files * When symbolic links (more specifically fast symlink) are created, the host directory is also fsync'ed. * Our application is also going to front an EMC disk array configured using RAID5 or RAID6. * We will be using multipathing so that we can assume that no disk errors will be repor...

In order to improve the performance of fsync, we use the outstanding ordered extents to avoid looking up the checksum from the csum tree. But we didn''t filter out the ordered extents whose csum is still being calculated, when we got those ordered extents, we had to wait for the csum calculation. It made the performance dropped down s...

Hello, Currently Dovecot (and any other application, which cares about e-mail delivery) does at least one fsync per mail delivery. Given that hard disk drives have a very limited IOPS, this effectively limits the maximum mail delivery performance to a very low value, under utilizing the available storage IO capacity. Calculating with an average mail size of 50 kB and an average consumer HDD with 120 IOPS...

...is means after a crash, "foo" is zero-length, and both the new and the old data has been lost, which is undesirable. This doesn''t happen when using ext3''s default settings because ext3 writes data to disk before metadata (which has performance problems, see Firefox 3 and fsync[2]) Ted T''so''s (the main author of ext3 and ext4) response is that applications which perform open(),write(),close(),rename() in the expectation that they will either get the old data or the new data, but not no data at all, are broken, and instead should call open(),write(),fsyn...

Hi! Afair, fsync()ing a directory is subject to platform-specific and implementation-defined behaviour, and may either - work as you'd want and (probably) expect - fail with an error - fail silently at least if your application targets more than one operating system/kernel - and even on one and the same pl...

Hi, tl;dr summary of below: flock() works, but what does it take to make sync()/fsync() work in a 3 node GFS cluster? I am under the impression that POSIX flock, POSIX fcntl(F_SETLK/F_GETLK,...), and POSIX read/write/sync/fsync are all supported in cluster operations, such that in theory, SQLite3 should be able to atomically lock the file (or a subset of page), modify pages, flush...

On Mon, Mar 5, 2018 at 8:21 PM, Paul Anderson <pha at umich.edu> wrote: > Hi, > > tl;dr summary of below: flock() works, but what does it take to make > sync()/fsync() work in a 3 node GFS cluster? > > I am under the impression that POSIX flock, POSIX > fcntl(F_SETLK/F_GETLK,...), and POSIX read/write/sync/fsync are all > supported in cluster operations, such that in theory, SQLite3 should > be able to atomically lock the file (or a subset of pag...

...nclude <errno.h> #include <fcntl.h> #include <string.h> int main() { printf("open aaa\n"); int fd = open("aaa", O_RDONLY | O_DIRECTORY, 0); if (fd < 0) { perror("open aaa"); } printf("sync aaa\n"); if(fsync(fd)) { perror("sync aaa"); } printf("OK\n"); return 0; } ``` I get such error: `sync aaa: Invalid argument` Is this expected for samba? Thanks in advance! Best Regards Cao

...r 5, 2018 at 11:26 AM, Raghavendra Gowdappa <rgowdapp at redhat.com> wrote: > > > On Mon, Mar 5, 2018 at 8:21 PM, Paul Anderson <pha at umich.edu> wrote: >> >> Hi, >> >> tl;dr summary of below: flock() works, but what does it take to make >> sync()/fsync() work in a 3 node GFS cluster? >> >> I am under the impression that POSIX flock, POSIX >> fcntl(F_SETLK/F_GETLK,...), and POSIX read/write/sync/fsync are all >> supported in cluster operations, such that in theory, SQLite3 should >> be able to atomically lock the file...

...n Gamari<bgamari.foss@gmail.com> writes: > >> ext4/XFS/JFS/btrfs should be better in this regard > >> > >> > > I am using btrfs, so yes, I was expecting things to be better. Unfortunately, > > the improvement seems to be non-existent under high IO/fsync load. > > > > btrfs is known to perform poorly under fsync. > Has the reason for this been identified? Judging from the nature of metadata loads, it would seem that it should be substantially easier to implement fsync() efficiently. - Ben -- To unsubscribe from this list: send th...

...gt; <rgowdapp at redhat.com> wrote: > > > > > > On Mon, Mar 5, 2018 at 8:21 PM, Paul Anderson <pha at umich.edu> wrote: > >> > >> Hi, > >> > >> tl;dr summary of below: flock() works, but what does it take to make > >> sync()/fsync() work in a 3 node GFS cluster? > >> > >> I am under the impression that POSIX flock, POSIX > >> fcntl(F_SETLK/F_GETLK,...), and POSIX read/write/sync/fsync are all > >> supported in cluster operations, such that in theory, SQLite3 should > >> be able to...

It wouldn''t be proper to start my first post here without congratulations and thanks to the ZFS team for such an impressive piece of work. Anyway, on to my query. I''ve been trying out ZFS, with a particular focus in reducing latency in a specific application. This application has a fair amount of random writing going on in the background (which, of course, ZFS will make

Libvirt has a fixed 15 second timeout for qemu to exit. If qemu is writing to a slow USB key, it can hang (in D state) for much longer than this - many minutes usually. To work around this, fsync the output file before closing the libvirt connection so that qemu shouldn't have anything (much) to write. We have to do this in a few places in the code. This is a hack - it would be better to find a way to fix this in libvirt. See also the description here: https://www.redhat.com/archives...