Summary
Risks of using LVM:
Vulnerable to write caching in kernel and hard disk on kernels before 2.6.33, or in VM guests
Harder to recover data due to more complex on-disk structures
Harder to resize filesystems correctly
Snapshots are hard to use, slow and buggy
Requires some skill to config...
How long should it take for me to mkfs.ext3 a 2TB volume?
@ewwhite: I personally don't like to use it myself. If I need to do any of the things LVM is meant for (other than snapshotting), I haven't planned well enough ;p
and slightly unusual speciality, so most of my *nix learning is self directed, and somewhat haphazard. A good chunk of stuff not to do with DR/IR type things is self learnt
I used to be a EE major, dropped out, did computer security, had a nervious break dowm then dropped out.
@ewwhite his point about easy of resizing is a bit stupid. His argument basically is. You can break things. Which is true no matter what tool you use to partition/resize things.
So I have a question, how did you create filesystem larger then 2TB if you don't like LVM? Did you switch over to GPT or something? Since MBR won't give you a partition larger then 2TB.
I honestly don't know if that even does anything anymore.
I know you have to look up the right argument to fsck to pass to it if you really want to check the filesystem, otherwise it'll just replay the journal and look at you funny.
@JourneymanGeek I actually use /data. Alot. It's just a nice scheme of doing things when you have vm's with one os-disk and one data-disk. The extra data disk always starts at E: for windows servers and /data on *nix
I have git repos in /srv/git, websites in /srv/www, etc.
Only one client where that's not the case, and that's only because I inherited the system that way, and untangling it would be a nightmare the client doesn't want to pay for.
$contract_sysadmin[-2] set up all the web sites in the user's home directory, and $contract_sysadmin[-1] set up a spaghetti tree of chroot jails and bind mounts so that $developer could work on them.
@JourneymanGeek Oh, it was for personal use. The only really funny part was, I had it on a Dell business laptop and the keyboard died. The guy who came out to replace the keyboard was completely lost...
@Zoredache Oh, you mean the quick 250 reputation? I really want a good set of solutions to turning off Linux console blanking. The question was pretty good, but all the answers suck.
I've got an Ubuntu server that boots up in text mode. It rarely has a screen or keyboard attached to it, but when I do attach a screen, I usually have to attach a keyboard too, because the darn console mode screen saver will be on and I'll need to hit a key to see what's going on.
I'm aware that...
Some are clearly distro-specific and don't mention which distro. The accepted answer is specific to Ubuntu (and maybe all Debian-derived distros). Nothing seems to cover Red Hat-derived distros, and I figured it would be better to offer a bounty than to ask a "duplicate" question.
@MikeyB Oh, just a silly IM conversation with a Calgarian. She sent me some YouTube videos that were blocked in 'mericuh so I got lazy and decided to just ask if a 'nadian friend had a VPN for me.
Is it possible to configure software RAID 5 on linux that uses system RAM for write cache? I have a file server with 8GB of RAM ... would be really cool if I could dedicate 4GB to write cache. If so, how is this done? Thanks.
so when a DB server crashes, and it's software RAID, and it's supermicro, so I don't have an IML log, watchdog or any of the nice tools to examine, I feel like we face more failures than we have to.
I have insight into how much we spend on these systems... so the one I'm working on is a dual E5620 box with 48GB RAM, an IPMI card, 2 x generic SATA disks and an 8Gb Qlogic fiber HBA
$3950
My price on the HP equivalent, DL360 G7, minus the FC HBA, is ~$3500
and it would have had ILO3, RAID, better cooling and power efficiency...
I have been looking for a way to back up my app's database which is hosted by heroku. It uses an sqlite database. What I am looking for is a way to add a button on my site which will allow me to download the database as an sqlite file. I am sure there is some simple fix I am overlooking but it w...
@ewwhite We tried silicon mechanics for one of our servers to see what we thought of their stuff. I wasn't impressed.
Boss liked the idea of going with a local company because it would be quicker to get on-site support. This was about a year before I convinced him that Virtualization had any legs as an operational plan.
@Adrian WAMP shouldn't be seen as anything more than a dev tool and these days it would be easier to set something up with VirtualBox or Similar to run a LAMP stack
@ewwhite I dunno. It's great stuff for piss-ant little orgs that don't bother with monitoring, clustering, and have no real budget or customers to worry about.
And I feel like that is the type of thing to trigger an ASR reboot on HP... or would give better logging. But I'm totally lost on the Supermicro hardware.
it's a physical server with fibre channel connection to SAN storage.
@MichaelHampton I remember DeLong talking about how they're not handing out little subnets, switching the thinking from managing scarcity to managing a super-abundance.
Starting to think that IPv6 and DevOps are going to completely shake our profession out. So many so-called admins that think security == NAT and can't manage even simple scripting.
And there goes one more failed migration back to whence it came from.
@ewwhite NAT permits a certain laziness of thinking that's more than a little disturbing. Plug this little box in and suddenly your network's secure! Idiots.
@ewwhite I do quite a bit of non-industry socializing around my motorcycles and home-brewing. The number of NAT & GUI-only "IT Admins" that try to talk shop with me pains me greatly.
Sadly I seem to belong to the GUI part myself, since that is almost all I have used in places where my coworkers also needed to understand things. And thus the knowledge which is most up to date. (Even though I started with CLI and Linux/Slackware)
They are not. My sister uses my old lenovo 3000 C100 (pentium M, single core, 1.73Ghz. 2GB RAM, replaced HDD (it failed after 5 years)... Battery life about 3 minutes
Which means use it with power plugged in
But it is still good enough to surf the net, check gmail etc
Getting a new laptop seems excessive
And with a good battery it used to last around 5 hours (6 hours fab. spec, 5.5 tested on my own with low screen brightness)
So I rather replace it with a new battery with freshly produced cells than get a new laptop
The middle part is a problem
I get get relative cheap batteries, but without guarantee that those have been shelved for years.
My own laptop is a Dell E6500. Think it is 4 years old. It lasts about 3 hours (used to be 5 hours)
When I leave home I used it for an average of 4 hours. Which now fails.
So I got a new battery
A bloody heavy/big one, since I expect them to be unavailable when I need to replace it again (say in another 4 years, or 8 years after the model was released)
I got a request from the man upstairs to setup Jenkins for Pretested commit (through a build at Jenkins, if all unit tests and other pass then commit it and build a dist). We're using svn here.
Is anyone clear about how this can be done with Jenkins? I am finding next to no information on it.
@MichaelHampton I really don't understand this whole Tomcat/Jenkins stuff. I probably need to figure out how it works at some point before I start interviewing
Since the website is about server problems i guess it is good to ask about this. I just want my viewers to be able to see a cached version of my website's main page and a couple other pages even if they are a month old when my server at my home is down. I use CloudFlare but i've read for some rea...