On 28/02/18 06:11 AM, Carlos E. R. wrote:
How does JFS compare to ReiserFS?
It handles multi-threading extremely well. I have a thread running on each of my CPU cores. As far as I can make out they are 'pooled' in that the threading is really multi-tasking and not dedicated to one FS.
Specially regarding small files.
Well, it doesn't pack them the way that ReiserFS does so it isn't as space efficient. But in terms of access, it seems to handle them damn well. I'm using it initially on my on-line photo 'archives', a partition/FS per year, and as I edit using Darktable the original RAW files are left unchanged and the list of edits stored in a sidecar file. So I have the huge 1Meg or 25Meg RAW files and a smaller sidecar file that may vary between about 1K and less than 10k, typically less than 4k. I'm not sure that ReiserFS will aggressively pack the 1.5k ... 2K files into the 4K blocks. So there doesn't seem to be much difference in space consumption. The difference I do see is in crash recovery. Both ReiserFS and JFS seem pretty indestructible! However on rebooting after a powerout crash I see delays as the ReiserFS does its FSCK stuff. No worries; that's reassuring, isn't it? But JFS has the journal and structure is preserved damn well, so it recovers FAST! (I don't know yes about having the journal on a separate device, but that consideration applies to other FS that use journals as well.) In both cases I'm not worried about loosing open files. As I said, this is photo stuff and the way Darktable works is that RAW file is left along and the changes/edits are in the sidebar file. I can't loose either of those on a crash, only the in-memory changes, unless the crash occurs at the instance I'm updating the sidecar file. But the 'create new/delete old' sequence means I still have the 'old'. Reliability by Design -- even on the layer above the FS. Would that more applications observed that kind of 'defensive programming'! Compression? "If and when"! Yes, but I'm not planning on using it. It doesn't offer much when it comes to RAW photo images or JPGs The conclusion is that I'm quite satisfied with JFS a an alternative to ReiserFS. https://en.wikipedia.org/wiki/Journaling_file_system https://en.wikipedia.org/wiki/JFS_(file_system) in particular see "Dynamic Inode Allocation" <quote> According to reviews[which?] and benchmarks[which?] of the available filesystems for Linux, JFS is fast and reliable, with consistently good performance under different kinds of load, contrary to other filesystems that seem to perform better under particular usage patterns, for instance with small or large files. Another characteristic often mentioned, is that it is light and efficient with available system resources and even heavy disk activity is realized with low CPU usage. </quote> http://jfs.sourceforge.net/project/pub/jfs.pdf http://jfs.sourceforge.net/project/pub/jfslayout.pdf - more than you need -- A: Yes. > Q: Are you sure? >> A: Because it reverses the logical flow of conversation. >>> Q: Why is top posting frowned upon? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org