search for: mtbf

I need to calculate some metrics such as Mean Time Between Failure (MTBF), etc (see http://www.cs.sandia.gov/~jrstear/ras for a more complete list). I have observations like start end state 1 2005-11-11 09:05:00 2005-11-11 12:20:00 Scheduled Downtime 2 2005-11-12 13:42:00 2005-11-12 14:45:00 Unscheduled Downtime...

Hi All, On several of my servers I seem to have a high rate of server crashes do to file system errors. So I have some questions related to this: Is there any Mean Time Between Failure ( MTBF) data for the ext3 file-system? Does increased partition size cause a higher risk of the partition being corrupted? If so, is there any data on the ratio between partition size and the likely hood of failure? Does ext3 on hardware raid (10) increase the possibility of file system corruption? Doe...

I'm working on a project involving reliability values (known failure rates) for a system with approximately 700 components with a set cconfiguration. I'm looking to compute a "parts-count" MTBF (mean time between failures) for the system. (See also MIL-HDBK-217) Is there anything in R that can help me with this? Thanks, Eric Jennings QA Technical Assistant Crane Electronics --Redmond 10301 Willows Road P.O. Box 97005 Redmond, WA 98073 PH 425.895.5039 e-mail eric.jennings@i...

...is to create a raidz2 pool for each shelf (i.e. 5TB per shelf of usable storage) and stripe across the shelves. This would let me lose up to two drives per shelf and still be operational. My only concern with this is if a shelf fails (SCSI card failure, etc) the whole system is down, however the MTBF for a SCSI card is WAAAAY higher than the MTBF of a hard drive... FWIW, we do have a backup strategy onto a SpectraLogic tape loader, so losing the whole array, while bad, won''t put us out of business, though I''d prefer it didn''t happen :) Obviously there are dozens of...

So after troubleshooting this for about a week, I was finally able to create a raid 10 device by installing the system, copying the md modules onto a floppy, and loading the raid10 module during the install. Now the problem is that I can't get it to show up in anaconda. It detects the other arrays (raid0 and raid1) fine, but the raid10 array won't show up. Looking through the logs

...Linux and Windows servers? Here are my requirements: SNMP trap collection, ability to import custom MIBs isup/isdown monitoring of ports and daemons Server health monitors (CPU, Disk, Memory, etc) SLA reporting with nice graphs Pager/Email/SMS alerts with groups, filters and escalations Built-in MTBF and MTTR reporting Robust parent-child relationships between monitors or probes. For example, the system must be smart enough to know that if 25 URLs have gone down all at once, that they belong to an apache process that has died. I don't want 25 alerts, I want *one* alert telling me that the...

...lty ZFS elements with ZFS pre-allocated "spares". Many hardware RAID controllers support the concept of ''spares''. Some allow the spare to be powered down - so that the spare does not fail just as the drive it is intended to replace, also fails! Whoops - the wonders of MTBF and the statistical likelyhood that identical drives, with identical runtimes and MTBF specs, operated in an identical runtime environment, are likely to fail within a short timeframe of one another. [0] Unfortunately, the "supply" of knowledgeable and talented admins in various technica...

...h 5 year warranty, 3. group, 240GiB ~ 100? The "Corsair Force LE" with 3 year warranty, 5. group, 240GiB ~ 70? >From the user standpoint, the difference between the Samsung SSD 850 Evo and the Corsair Neutron XTi is not that big. Samsung: TLC 3D Flash, 75TBW @ 250 Gib size, 1,5 Mh MTBF, 512MB Cache Corsair: MLC 2D Flash, 160TBW @ 240 GiB size, ?? MTBF, no RAM-Cache Either Corsair does not want to a) test for MTBF, b) show the MTBF, or c) they are not really satisfied with it and thus hide it. *shrugs* http://www.anandtech.com/show/9799/best-ssds http://www.anandtech.com/show/1...

.... group, 240GiB ~ 100? > The "Corsair Force LE" with 3 year warranty, 5. group, 240GiB ~ 70? > > From the user standpoint, the difference between the Samsung SSD 850 Evo > and the Corsair Neutron XTi is not that big. > Samsung: TLC 3D Flash, 75TBW @ 250 Gib size, 1,5 Mh MTBF, 512MB Cache > Corsair: MLC 2D Flash, 160TBW @ 240 GiB size, ?? MTBF, no RAM-Cache > > Either Corsair does not want to a) test for MTBF, b) show the MTBF, or > c) they are not really satisfied with it and thus hide it. *shrugs* > > > http://www.anandtech.com/show/9799/best-ssds...

Hi all I have a test system with snv134 and 8x2TB drives in RAIDz2 and currently no Zil or L2ARC. I noticed the I/O speed to NFS shares on the testpool drops to something hardly usable while scrubbing the pool. How can I address this? Will adding Zil or L2ARC help? Is it possible to tune down scrub''s priority somehow? Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 roy at

...---- Original Message ----- From: "Dana Nowell" <DanaNowell@cornerstonesoftware.com> To: <asterisk-users@lists.digium.com> Sent: Thursday, July 22, 2004 11:57 AM Subject: Re: [Asterisk-Users] RAID affecting X100P performance... > In an article on IDE vs. SCSI I read that MTBF numbers for IDE were > frequently caculated at 8 hours on 16 hours off per day (assumes desktop > usage) but SCSI drives were calculated at 24hrs on per day. So even though > the MTBF numbers look the same ... The main reason is, reportedly, better > quality controller parts and motor...

FYI, Seagate has announced a new enterprise SSD. The specs appear to be competitive: + 2.5" form factor + 5 year warranty + power loss protection + 0.44% annual failure rate (AFR) (2M hours MTBF, IMHO too low :-) + UER 1e-16 (new), 1e-15 (5 years) + 30,000/25,000 4 KB read IOPS (peak/aligned zero offset) + 30,000/10,500 4 KB write IOPS (peak/aligned zero offset) http://www.seagate.com/www/en-us/products/servers/pulsar/pulsar/ http://storageeffect.media.seagate.com/2009/12/storage-effec...

Size/Speed/write cycles have gone way up, price has gone way down. More common than CompactFlash and no need for an adapter. So is it feasible to run an Asterisk server on something like this? With a MTBF of 1million write cycles coupled with dynamic wear management on a 4Gig USB drive, lifetime is a non-issue. Just wondering how well it works, if it works.

...ead, because it's much better to have a number of point-to-point devices with direct pins to a PHY to a wide ASIC than a wide bus that is shared by all devices. And these 10K RPM SATA models are rolling of the _exact_same_ fab lines as their SCSI equivalents, with the same vibration specs and MTBF numbers. They are not "commodity" [S]ATA drives, of which many 7,200rpm SCSI drives are even now sharing (and share the same 0.4Mhr MTBF as commodity [S]ATA). -- Bryan J. Smith mailto:b.j.smith at ieee.org

I would prefer the behavior was different to what it is of I/O stopping. The argument I heard for the long 42 second time out was that MTBF on a server was high, and that the client reconnection operation was *costly*. Those were arguments to *not* change the ping timeout value down from 42 seconds. I think it was mentioned that low ping timeout settings could lead to high cpu loads with many clients trying to reconnect if a short time...

If we''ve abandoned the idea of putting the number of redundant blocks into the top bits of the type bitmask (and I hope we have), then we''re fairly much there. Current code is at: git://, http://git.infradead.org/users/dwmw2/btrfs-raid56.git git://, http://git.infradead.org/users/dwmw2/btrfs-progs-raid56.git We have recovery working, as well as both full-stripe writes

...rations; the SAS model offers one quarter the buffer (16MB vs 64MB on the SATA model), the same rotational speed, and costs 10% more than its enterprise SATA twin. (They also offer a Barracuda XT SATA drive; it''s roughly 20% less expensive than the Constellation drive, but rated at 60% the MTBF of the others and a predicted rate of nonrecoverable errors an order of magnitude higher.) Assuming I''m going to be using three 8-drive RAIDz2 configurations, and further assuming this server will be used for backing up home directories (lots of small writes/reads), how much benefit will...

On Fri, October 28, 2016 2:42 am, Alessandro Baggi wrote: > Il 27/10/2016 19:38, Yamaban ha scritto: >> For my personal use I would replace that Drive asap. >> - There is no warranty for it anymore (time since buy) >> - You can't buy it new anymore (discontinued) >> - There are more reliable drives available. >> >> I'd go for a Samsung Evo 850, that

I am getting a few bad sector messages in my /var/log/messages. I have read where an "fsck -c -c /dev/hda" may be what I need. Before I go doing such things I am looking for confirmation that that is what I should do. Anyone please comment on how to tell linux to not use sectors in my disk. This is stright IDE no raid not nothing at this point /dev/hda is all. Thanks, jerry

for s10u2, documentation recommends 3 to 9 devices in raidz. what is the basis for this recommendation? i assume it is performance and not failure resilience, but i am just guessing... [i know, recommendation was intended for people who know their raid cold, so it needed no further explanation] thanks... oz -- ozan s. yigit | oz at somanetworks.com | 416 977 1414 x 1540 I have a hard time