On Mon, Jul 15, 2013 at 03:33:09PM +1000, Tim Connors wrote:
On Mon, 15 Jul 2013, Craig Sanders wrote:
I've been using LVM for a lot longer than ZFS but I still find it difficult and complicated to work with, and the tools are clumsy and awkward.
Really? You haven't come across HP-UX's LVM or veritas cluster storage's lvm then :)
they're not that much worse than lvm. OK, so call them 1st generation, lvm gen 1.5 and lvm2 gen 1.75
I find zfs obtuse, awkward, inflexible, prone to failure and unreliable.
you must be using a different zfs than the one i'm using because that description is the exact opposite in every respect of my experience with zfs.
One day when I got sick of the linux kernel's braindead virtual memory management, I tried to install debian kfreebsd, but gave up before I finished installation because not having lvm seemed so primitive. I was probably just trying to use the wrong tool for the job.
probably. the freebsd kernel has zfs built in, so zfs would be right tool there.
Does anyone use zfs's dedup in practice? Completely useless.
yes, people do. it's very heavily used on virtualisation servers, where there are numerous almost-identical copies of the same VM with minor variations. it's also useful on backup servers where you end up with dozens or hundreds of copies of the same files (esp. if you're backing up entire systems, including OS)
Disk is a heck of a lot cheaper than RAM. Easier to add more disk too compared to
yep, that fits my usage pattern too...i don't have that much duplicate data. i'm probably wasting less than 200GB or so on backups of linux systems in my backup pool including snapshots, so it's not worth it to me to enable de-duping. other people have different requirements.
maxing out a server and having to replace *everything* to add more RAM (dissapointingly, I didn't pay $250 to put 32GB in my new laptop. I hoped to replace the 16GB with 32GB when it becomes more economical, but when I opened it up, I found there were only 2 sockets. According to the manual that wasn't supplied with the laptop, the other two sockets are under the heatsink wedged underneath the keyboard, and not user-replacable. According to ebay, within the past couple of weeks, they did start selling 16GB sodimms, but no idea whether my haswell motherboard will be able to take them when it comes time to upgrade (which is probably very soon, judging by how iceape's memory usage just bloated even futher beyond reasonableness)).
i've found 16GB more than adequate to run 2 4TB zpools, a normal desktop with-the-lot (including firefox with dozens of windows and hundreds of tabs open at the same time) and numerous daemons (squid, apache, named, samba, and many others). of course, a desktop system is a lot easier to upgrade than a laptop if and when 32GB becomes both affordable and essential. FYI: NoScript and AdBlock Plus stop javascript from using too much RAM as well as spying on you.
Au contraire. If you use lvresize habitually, one day you're going to accidentally shrink your LV instead of expand it, and the filesystem below it will then start accessing beyond end of device, with predictably catastrophic results. Use lvextend prior to resize2fs, and resize2fs shrink prior to lvreduce, and you'll be right.
the risk of typing '-' rather than '+' does not scare me all that much. i tend to check and double-check potentially dangerous command lines before i hit enter, anyway. craig -- craig sanders <cas@taz.net.au> BOFH excuse #286: Telecommunications is downgrading.