On Thu, Sep 22, 2011 at 10:06 PM, Stan Hoeppner <s...@hardwarefreak.com>wrote:
> On 9/21/2011 10:43 AM, Camaleón wrote: > > ...in my case, was >> >> flooding the "/var/log/syslog" file. Then it's too late and your system >> may become unstable and slow meaning that you are royaly hosed :-) >> > > Which is why every old school Unix guru (and younger smart ones as well) > will tell you to put /var on a separate filesystem (partition), and better > yet on a separate physical device. The first protects against a single full > filesystem taking the system down. The second does the same and also makes > sure all log related disk bandwidth is on a separate spindle, thus avoiding > the performance degradation when a runaway process spams the log file with > dozens or hundreds of IOs per second. Note that 7.2k SATA drives can only > tackle about 150 IOPS. 5.2k laptop drives about 100. > There was a geek in our lab long time ago, the partition was inherited from him. Before I did not understand. Later gradually started to know something, but seems too late. > > Even low end SSD can do 2500 IOPS, 15x that of a 7.2k drive. And most SSDs > are small. So if you have an SSD in this runaway logging scenario you could > potentially fill the log filesystem in a matter of minutes. > > Moral of the story: Keep /var/log on a separate filesystem for laptops and > desktops. Keep it on a separate physical device on servers. With a RAID > setup, a separate partition on the LUN/virtual disk serves the same purpose. > Unrelated to this particular problem, but valuable knowledge nonetheless, > is to have a boot partition separate from the / partition as well. > What's the recommended reserved size for the /var/log partition. I can jotted down and take reference in future. > > Ease of use and "Linux on every desktop" proponents evangelize using a > single partition/filesystem, which is the default Microsoft setup BTW, so > it's simpler for the non technical user, though inherently less safe. Those > who have used *nix for a while, especially server administrators, who have > seen problems like this first hand, evangelize separate > partitions/filesystems for reliability, resiliency, and recovery. > > The former crowd goes for a "2 hour" afternoon hike in the desert and takes > no supplies, only a digital camera, an iPhone, and a small water bottle. > It's only a 2 hour hike right? > > The latter takes a backpack containing a gallon of water, a first aid kit > including anti venom for treating rattlesnake bites, sun block, burn spray, > an MRE, 2 flashlights with spare batteries, a tool kit, a shovel, a wind > proof butane lighter, a pup tent, sleeping bag, blankets, cell phone and CB > radio with extra batteries, and a rain coat. > > An hour into his hike, the former takes a rattler bite to the ankle, falls > 20 feet off the rock he's climbing and brakes his right femur. This > particular bite is not by itself life threatening. With no signal on his > iPhone he's unable to call or text for help. He's immobile and can't walk > out. He decides to lie and wait for the next hiker to come by, not knowing > when that will be. He drinks all his meager water supply, baking in the > afternoon sun. A storm rolls in just before night fall, the temperature > dropping to 40F, dropping a short but massive rain fall. Huddled between > the boulders he shivers all night from the wet and cold, in shorts and a > t-shirt. Before dawn he expires due to a combination of venom, dehydration, > hypothermia, and shock. > > A month later the latter hikes out and back without issue, in two hours. > Had the former packed and prepared like the latter, he'd be alive today, at > worst maybe with a slight limp. > Reading the above three sentences I needed look up dictionaries. Finally got, seems a story, or an analogue. > -- > Stan > > > > -- > To UNSUBSCRIBE, email to > debian-user-REQUEST@lists.**debian.org<debian-user-requ...@lists.debian.org>with > a subject of "unsubscribe". Trouble? Contact > listmas...@lists.debian.org > Archive: > http://lists.debian.org/**4E7B40CF.3040101@**hardwarefreak.com<http://lists.debian.org/4e7b40cf.3040...@hardwarefreak.com> > > -- Best Regards, lina
