George Georgovassilis writes about information technology architecture
I wasn't aware of tar's --blocking-factor parameter: -b, --blocking-factor=BLOCKS Set record size to BLOCKSx512 bytes. This actually reduces CPU load and backup creation times measurably. Figures for backing up 7GB on my home NAS: Setting Seconds Setting Minutes.Secods------------------------------default 1.18 512 1.071024 1.052048 1.08 The fastest setting (1024) is 11% faster than the slowest (default).
On a rather hefty rsync job between two local ext4 filesystems, writing on the target (a mechanical hard drive which should be able to sustain 100 mb/s) would fluctuate strongly (between 0 mb/s and 160 mb/s) and effectively slow down to a few mb/s on average after a few minutes. While I didn't find the … Continue reading Slow rsync on ext4 filesystem
When browsing large windows (samba) shares with Ubuntu Nautilus (that's the equivalent of the Windows File Explorer) I observed that shares which include many files and directories (a few hundred) take a few seconds to browse over WiFi, but almost instantly display over a fast LAN. A similar difference in speed is noticeable when searching … Continue reading Nautilus browsing large windows share is slow
I'm running a large (>20TB) ext4 file system and noticed that the first substantial write operation after mounting is very slow and involves plenty of drive activity. The reason seems to be some memory structure initialisation as described here: https://linux-ext4.vger.kernel.narkive.com/SUFNE520/ext4-slow-performance-on-first-write-after-mount The workaround is thankfully as simple as running this command in a script after mounting … Continue reading First write operation to large ext4 file system is slow
TL;DR: HTTP compression can delay rendering of web resources HTTP permits content to be served with different encodings, some of which can be used to compress [1] the data volume transferred over the network, which has become a frequent suggestion [2] towards optimising websites for performance. It turns out that the deflation phase of the … Continue reading HTTP compression and incremental rendering
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