Hi We have a number offices accommodating 4-6 people each hence it is very important for PBX to be fanless and silent. We have been looking at using IDE flash disks also called DOM. The performance tests we have done so far satisfy our requirements, however we are concerned with DOM durability. We have installed debian and vanilla asterisk on 1GB DOM. All seems to work fine at the moment however will DOM last? How long it will last? Is anyone able to share similar experience? Any other information/tips? Regards, Juan _________________________________________________________________ News, entertainment and everything you care about at Live.com. Get it now! http://www.live.com/getstarted.aspx
On Tue, 11 Sep 2007, Juan Sandro wrote:> > Hi > > We have a number offices accommodating 4-6 people each hence it is very > important for PBX to be fanless and silent. We have been looking at using > IDE flash disks also called DOM. The performance tests we have done so far > satisfy our requirements, however we are concerned with DOM durability. > > We have installed debian and vanilla asterisk on 1GB DOM. All seems to work > fine at the moment however will DOM last? How long it will last? Is anyone > able to share similar experience? Any other information/tips?You could read the archives from a week or 2 ago under the heading: Build your own "appliance" I use these deices, but I unload them entirely into RAM. I have seen devices (eary mikrotik routers?) with them as live (and ext3 no less!) filesystems, but I would be very concerend about their lifespan. One thing to note and this might well shaft you is that they use POI mode rather than DMA (or at least the ones I'm using do) so they will really crowbar the bus & cpu when doing transfers to/from them, however with only 4-6 people and not doing much like writing voicemail, etc. you may not notice it. If you're sticking a "normal" disctibution on it, I'd suggest dumping the DOM and getting a laptop type IDE/SATA drive and using that instead. It's not silent, but will be very quiet. Gordon
On Tue, 11 Sep 2007 04:04:27 -0500, Juan Sandro wrote:> >Hi > >We have a number offices accommodating 4-6 people each hence it is very >important for PBX to be fanless and silent. We have been looking at using >IDE flash disks also called DOM. The performance tests we have done so far >satisfy our requirements, however we are concerned with DOM durability. > >We have installed debian and vanilla asterisk on 1GB DOM. All seems to work >fine at the moment however will DOM last? How long it will last? Is anyone >able to share similar experience? Any other information/tips?Why reinvent the wheel...try Astlinux. It's built to be run from flash devices and includes both Asterisk and edge routing capability for small PCs or embeded hardware. Michael -- Michael Graves mgraves at pixelpower.com Sr. Product Specialist www.pixelpower.com Pixel Power Inc. mgraves at mstvp.com o713-861-4005 c713-201-1262 skype mjgraves fwd 54245
Juan Sandro wrote:> Hi > > We have a number offices accommodating 4-6 people each hence it is very > important for PBX to be fanless and silent. We have been looking at using > IDE flash disks also called DOM. The performance tests we have done so far > satisfy our requirements, however we are concerned with DOM durability. > > We have installed debian and vanilla asterisk on 1GB DOM. All seems to work > fine at the moment however will DOM last? How long it will last? Is anyone > able to share similar experience? Any other information/tips? >I worried a lot about the same, in the end I went for a small laptop drive for "safety" (it's inaudible) However, this came up on slashdot recently and if you search around the logic seems to be that: - Flash rewrites quite a few times - The good stuff has wear levelling so that most roughly speaking the whole thing should work until it suddenly all fails - Given a big enough drive with a fair bit of free space then you should find it hard to wear it out in less than quite a few years even if you are hitting it quite hard (probably multiples of this). Simply do the maths to get the rough life So basically it seems that given a large enough flash drive with decent wear levelling the lifetime should be completely ample... ...Thats the theory anyway. I feel quite bullish about the whole thing, but I think I would avoid the *really* discounted cheapo flash drives since they may not have the correct wear levelling. Decent brand names should be fine though (and you can google for details on their specs) Ed W
CF flash deviced work fine provided that a) The CF has a wear leveling controller inside (not all do, especially the cheap ones) so even a ext2 filesystem wan't create problems b) You use a distro with read only (or partial write) filesystem .i.e logs to ram or remote server etc Other than that we have deployed a very large number of devices with embedded linux in a CF (not all of them asterisk) with minimal problems Stelios S. Koroneos Digital OPSiS - Embedded Intelligence http://www.digital-opsis.com> -----Original Message----- > From: asterisk-users-bounces at lists.digium.com > [mailto:asterisk-users-bounces at lists.digium.com]On Behalf Of Juan Sandro > Sent: Tuesday, September 11, 2007 12:04 PM > To: asterisk-users at lists.digium.com > Subject: [asterisk-users] Flash IDE > > > > Hi > > We have a number offices accommodating 4-6 people each hence it is very > important for PBX to be fanless and silent. We have been looking at using > IDE flash disks also called DOM. The performance tests we have done so far > satisfy our requirements, however we are concerned with DOM durability. > > We have installed debian and vanilla asterisk on 1GB DOM. All > seems to work > fine at the moment however will DOM last? How long it will last? Is anyone > able to share similar experience? Any other information/tips? > > Regards, > > Juan > _________________________________________________________________ > News, entertainment and everything you care about at Live.com. Get it now! > http://www.live.com/getstarted.aspx > _______________________________________________ > > Sign up now for AstriCon 2007! September 25-28th. > http://www.astricon.net/ > > --Bandwidth and Colocation Provided by http://www.api-digital.com-- > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >
> So basically it seems that given a large enough flash drive with decent > wear levelling the lifetime should be completely ample...> > ...Thats the theory anyway.> > I feel quite bullish about the whole thing, but I think I would avoid > the *really* discounted cheapo flash drives since they may not have the > correct wear levelling. Decent brand names should be fine though (and > you can google for details on their specs)Hi Yeah we contacted a distributor of PQI flash memory. They sent us a wear leveling formula. Here it is: Example: A 256MB flash device writing 128KB data into flash device the formula as below: ( With wear leveling ). DOM Lifetime ( Theory ) = (256MB-100MB)*100K*0.95 / (128KB/sec) *60*60*24= 1340.06 days # ?0.95? : After the flash being format the capacity might lower than the certain capacity.# ?60*60*24? : 86400 writing times per day. 1 time /sec# ?100MB? : The size of your OS & AP. In this case we set it as ?100MB?#?128KB/sec?: The data size that writing onto flash device per second.# ?100K? : The limitation of flash memory?s P/E cycles. P.S. : NAND type flash (Small block) : 1 Block = 32 page * 512byte = 16KBNAND type flash (Large block): 1 Block = 64 page * 2Kbyte = 128KBIf the data less than 128KB we recommend you still calculate it with 128KB. NOW.. I am truly confused :) Juan _________________________________________________________________ News, entertainment and everything you care about at Live.com. Get it now! http://www.live.com/getstarted.aspx -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20070912/98cb67ce/attachment.htm