i can only speak from experience, but i have had fossil and venti running on a single ssd (on a radpberry pi) for 5 years now - no rotating discs left at home.
i have mtime changes and ephemeral snapshots turned off to reduce the update rate. i chose a sandisk card, and take backups just in case… so far so good. -Steve > On 29 May 2024, at 4:39 am, o...@eigenstate.org wrote: > > Finally,. SSDs just die over time. Especially if they are > not powered on and refreshing. JEDEC specs say that they > should retain data for 1 year unplugged when stored at 30 > degrees celsius, assuming the internet isn't lying to me. > > Keep backups. > > Quoth Dave Eckhardt <davide...@cs.cmu.edu>: >>> For the napkin calculation: On disk, the IEntry is 38Bytes. Alas, >>> writes occur always in (the ssd internal) blocksize. So, essentially >>> (assuming 4096 byte blocksize, which is quite optimistic), we have >>> a write efficiency of less than 1 percent. >> >> While I see how such a model can predict disaster, I don't think that >> model matches how FTLs work, because it can't. >> >> Many file systems (FAT, ext2/3/4) write the same logical block over >> and over and over and over and over. I think the default interval >> for ext4 to synch the superblock and the journal is five seconds, >> which if true is more than 15,000 times every *day* for a busy >> file system (and I think lots of Linux systems are busy in that >> sense). >> >>> A good firmware in the ssd could avoid needing a new block for the >>> write, if all bits are changed in teh same direction by the new >>> data. >> >> Again, I believe this model predicts that no regular Linux file >> system can be used on any SSD, thus I believe this model is not >> accurate. >> >> To quote Wikipedia: >> >> https://en.wikipedia.org/wiki/Flash_memory_controller >> >>> The mapping units of an FTL can differ so that LBAs are mapped >>> block-, page- or even sub-page-based. Depending on the usage >>> pattern, a finer mapping granularity can significantly reduce >>> the flash wear out and maximize the endurance of a flash based >>> storage media. >> >> Also, I feel as if this point is several assumption layers deep. >> I think one user reported an unknown number of failures in two >> sets of SSDs of unknown brand and model. I don't think we know >> that it was venti SSDs that went bad as opposed to fossil SSDs, >> let alone knowing it was index SSDs for venti. >> >>> It seems, venti in its current form is a ssd killer, if they >>> are used for the isects. >> >> I don't think this claim is yet supported well. >> >> Dave Eckhardt ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/T2ca67486c7a13a77-M8bfe23b05de7c8450157011c Delivery options: https://9fans.topicbox.com/groups/9fans/subscription
