Re: [Asterisk-Users] Hard drive write cache
How about having the asterisk config on CF or USB drives and the OS, Asterisk on a Linux LiveCD. That way you can mail out PBX upgrades to the customer they pop it into the CD drive and reboot. Config for DHCP boot, /etc/asterisk (or /etc entirely) on a USB dongle would work great. -- Matthew S. Crocker Vice President Crocker Communications, Inc. Internet Division PO BOX 710 Greenfield, MA 01302-0710 http://www.crocker.com ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] Hard drive write cache
On Thu, Jun 15, 2006 at 08:28:57PM -0400, Matthew Crocker wrote: How about having the asterisk config on CF or USB drives and the OS, Asterisk on a Linux LiveCD. That way you can mail out PBX upgrades to the customer they pop it into the CD drive and reboot. Actually, the minute they pop out the CD drive, the system stops working. Unless the system runs completely from RAM. Config for DHCP boot, /etc/asterisk (or /etc entirely) on a USB dongle would work great. It means that every small config change will have to require a reboot. And an attented one. No remote upgrades. Also note that separating code from config is not as trivial as it sounds. For instance, much of extensions.conf is actually code, and should belong under /usr/share on such a system (using #include). -- Tzafrir Cohen sip:[EMAIL PROTECTED] icq#16849755 iax:[EMAIL PROTECTED] +972-50-7952406 [EMAIL PROTECTED] http://www.xorcom.com ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] Hard drive write cache
99.999% I suspect you will see this drop as traditional PBX'es start to use commodity parts. My Mitel ICP 3300 has a Maxtor 10 gig hard drive in it (same as an Xbox!) ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] Hard drive write cache
Hm.that's interesting to know. I'll bet they boot from CF but I could be wrong. Any chance you can get some photo's of the inside of that thing? Those Mitels have a built in PoE switch do they not? Anything else special about them that cannot be duplicated in an Asterisk Server? Not that a couple 4 port PoE switches inside is not possible but I haven't heard of anyone doing that. -Original Message- From: Colin Anderson [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 14, 2006 7:19 AM To: 'Asterisk Users Mailing List - Non-Commercial Discussion' Subject: RE: [Asterisk-Users] Hard drive write cache 99.999% I suspect you will see this drop as traditional PBX'es start to use commodity parts. My Mitel ICP 3300 has a Maxtor 10 gig hard drive in it (same as an Xbox!) ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] Hard drive write cache
They have a 4 port switch, but not PoE. It's decommissioned but we haven't taken it out of the rack yet, if I'll remember when we derack it I'll snap a pic. AFAIC, there is nothing in them that cannot be duplicated in a decent Asterisk setup, and in fact the featureset that we have fleshed out in our Asterisk setup stands head and shoulders above the Mitel featureset with the only exception of voice recognition, which is actually quite good (and extremely expensive - the cost for the voice recognition as a single feature is equivalent to the cost of our ENTIRE Asterisk rollout, including phones.) -Original Message- From: shadowym [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 14, 2006 2:25 PM To: 'Asterisk Users Mailing List - Non-Commercial Discussion' Subject: RE: [Asterisk-Users] Hard drive write cache Hm.that's interesting to know. I'll bet they boot from CF but I could be wrong. Any chance you can get some photo's of the inside of that thing? Those Mitels have a built in PoE switch do they not? Anything else special about them that cannot be duplicated in an Asterisk Server? Not that a couple 4 port PoE switches inside is not possible but I haven't heard of anyone doing that. -Original Message- From: Colin Anderson [mailto:[EMAIL PROTECTED] Sent: Wednesday, June 14, 2006 7:19 AM To: 'Asterisk Users Mailing List - Non-Commercial Discussion' Subject: RE: [Asterisk-Users] Hard drive write cache 99.999% I suspect you will see this drop as traditional PBX'es start to use commodity parts. My Mitel ICP 3300 has a Maxtor 10 gig hard drive in it (same as an Xbox!) ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] Hard drive write cache
Hi, shadowym wrote: I am looking at ways to harden my asterisk install to prevent computer related issues from happening. I am concerned about about disk write cache. That seems to be a major source of hard drive corruption on power failure. Hard Drive corruption is simply unacceptable for the 99.999% uptime requirements of my Asterisk install that needs to be as reliable as a proprietary PBX. Things to consider: - Use compactflash to boot and run asterisk, add disk only for voicemail - Run the entire setup from a ram disk, make commit/rollback facilities to write to disk - Extra servers are cheap - you could use LinuxHA to failover the server. Florian ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] Hard drive write cache
These days you don't have to worry much about your write cache unless you're running application where once single byte changed will affect whole file. Look at it this way, the only corruption will occur is whatever the files were open by asterisk at the time of the crash. And only up to the point where the file was last open. As far as I know asterisk does not keep cdr or log files open so you would loose only the data that was written at the time of the power failure. Any journaling file system (ext3, resierfs, xfs, etc) will easily handle any power failure event. Your files will not be corrupt but could miss some of the data. At the most you will loose 10-50 cdr entries written to you log files. If you post CDR to a remote SQL database then you asterisk install and linux is more or less static and will not be affected by the power failure. What you need to do is minimise the writes to hard disk's: 1 - Send syslog to remote server and do not do ANY syslogs Or keep the circular buffer in memory if you have plenty of it. 2 - Send CDR's to SQL server (or log to ramdisk and send to remote server every few minutes via SSH) 3 - Do not record any calls (or do that somewhere else) 4 - Stop any services that write/read data on regular intervals. If you have no writes you have nothing to worry about during power failure and journaling file system will take care of the rest. Keep your partition size really small so that fsck will not take much time. You have to be realistic, you cannot achieve 99.999% uptime. That's 5 minutes per year downtime. You will have more or less 100% until your first hardware failure. Even if you have all the hardware components pre-purchased it will still take you 2-12 hours to detect, diagnose and fix the fault if you lucky. So your 5 minuets If the business is demanding 99.999% then it should be prepared to invest into the hardware. I would recommend a cluster or even better a fault tolerant server. Those are expensive but you can pretty much rule out the hardware failure and swap all of the failed components while the system is running (cpu, memory, hdd, etc). Look at Stratus or NEC FT servers if you need hardware redundancy. They're expensive but will give you the hardware reliability you need. Or get a traditional PABX :) -Original Message- From: [EMAIL PROTECTED] [mailto:asterisk-users- [EMAIL PROTECTED] On Behalf Of shadowym Sent: Tuesday, 13 June 2006 10:34 To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] Hard drive write cache I am looking at ways to harden my asterisk install to prevent computer related issues from happening. I am concerned about about disk write cache. That seems to be a major source of hard drive corruption on power failure. Hard Drive corruption is simply unacceptable for the 99.999% uptime requirements of my Asterisk install that needs to be as reliable as a proprietary PBX. Of course I will be using redundant power supplies, raid 1 and use a UPS. None of those things mean much if the power cords accidentally get pulled from the back of the server. Unlikely as it may be I have to consider ALL possibilities. So is disabling the write cache a good way to reduce the risk of hard drive corruption for an Asterisk server? I am not too concerned about the reduced performance/lifetime of hardrives with write cache disabled since Asterisk is not a very write intensive environment. Even with lot's of voicemail going on. Any other recommendations/links for increasing the reliability of Asterisk servers? ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] Hard drive write cache
The cold hard truth is that if Asterisk cannot achieve 99.999% uptime without becoming much more expensive that a traditional PBX then it is not a viable alternative. Even elcheapo Key systems are rated for five nines. That is what the telco world requires unless your just using Asterisk in your basement as a hobby or as a one man company. Redundant Servers is moving into the realm of non-competitive with Traditional PBX IMHO. I don't care about corruption of the CDR or any of the logging/database information. All I care about is the ability make phone calls after power failure. That IS the MAIN function of a PBX. Not call centers, databases, CDR, click 2 call, and all the other bells and whistles. -Original Message- From: Boris Bakchiev [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 2:13 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: RE: [Asterisk-Users] Hard drive write cache These days you don't have to worry much about your write cache unless you're running application where once single byte changed will affect whole file. Look at it this way, the only corruption will occur is whatever the files were open by asterisk at the time of the crash. And only up to the point where the file was last open. As far as I know asterisk does not keep cdr or log files open so you would loose only the data that was written at the time of the power failure. Any journaling file system (ext3, resierfs, xfs, etc) will easily handle any power failure event. Your files will not be corrupt but could miss some of the data. At the most you will loose 10-50 cdr entries written to you log files. If you post CDR to a remote SQL database then you asterisk install and linux is more or less static and will not be affected by the power failure. What you need to do is minimise the writes to hard disk's: 1 - Send syslog to remote server and do not do ANY syslogs Or keep the circular buffer in memory if you have plenty of it. 2 - Send CDR's to SQL server (or log to ramdisk and send to remote server every few minutes via SSH) 3 - Do not record any calls (or do that somewhere else) 4 - Stop any services that write/read data on regular intervals. If you have no writes you have nothing to worry about during power failure and journaling file system will take care of the rest. Keep your partition size really small so that fsck will not take much time. You have to be realistic, you cannot achieve 99.999% uptime. That's 5 minutes per year downtime. You will have more or less 100% until your first hardware failure. Even if you have all the hardware components pre-purchased it will still take you 2-12 hours to detect, diagnose and fix the fault if you lucky. So your 5 minuets If the business is demanding 99.999% then it should be prepared to invest into the hardware. I would recommend a cluster or even better a fault tolerant server. Those are expensive but you can pretty much rule out the hardware failure and swap all of the failed components while the system is running (cpu, memory, hdd, etc). Look at Stratus or NEC FT servers if you need hardware redundancy. They're expensive but will give you the hardware reliability you need. Or get a traditional PABX :) -Original Message- From: [EMAIL PROTECTED] [mailto:asterisk-users- [EMAIL PROTECTED] On Behalf Of shadowym Sent: Tuesday, 13 June 2006 10:34 To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] Hard drive write cache I am looking at ways to harden my asterisk install to prevent computer related issues from happening. I am concerned about about disk write cache. That seems to be a major source of hard drive corruption on power failure. Hard Drive corruption is simply unacceptable for the 99.999% uptime requirements of my Asterisk install that needs to be as reliable as a proprietary PBX. Of course I will be using redundant power supplies, raid 1 and use a UPS. None of those things mean much if the power cords accidentally get pulled from the back of the server. Unlikely as it may be I have to consider ALL possibilities. So is disabling the write cache a good way to reduce the risk of hard drive corruption for an Asterisk server? I am not too concerned about the reduced performance/lifetime of hardrives with write cache disabled since Asterisk is not a very write intensive environment. Even with lot's of voicemail going on. Any other recommendations/links for increasing the reliability of Asterisk servers? ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ --Bandwidth and Colocation
Re: [Asterisk-Users] Hard drive write cache
shadowym wrote: The cold hard truth is that if Asterisk cannot achieve 99.999% uptime without becoming much more expensive that a traditional PBX then it is not a viable alternative. Even elcheapo Key systems are rated for five nines. Even massive redundant public exchanges struggle for 99.999% up time. No key system gives that. Its about 1 hour down in 10 years. That is what the telco world requires unless your just using Asterisk in your basement as a hobby or as a one man company. Redundant Servers is moving into the realm of non-competitive with Traditional PBX IMHO. A traditional PBX of any decent size is highly redundant. More so than you will easily achieve with *. How do you expect * to achieve high reliability without redundant servers. I don't care about corruption of the CDR or any of the logging/database information. All I care about is the ability make phone calls after power failure. That IS the MAIN function of a PBX. Not call centers, databases, CDR, click 2 call, and all the other bells and whistles. Steve ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] Hard drive write cache
If all you are worried about is the write cache on the disks, why not just put the system on a UPS set to shutdown the system in the event of power failure, then place both the UPS and asterisk servers in a locked rack. In the event of a power failure (or someone knocking the plug loose, which you can use locking plugs to further mitigate), the system will stay up on battery power then shut itself down to prevent data corruption. I doubt you will get that level of uptime, but there are other options to help achieve higher reliability. You can run the OS and asterisk on a solid state disk, and have voicemail and whatever else you want to go to rotating disks. That will also help with power usage on the server when using the UPS. Industrial flash disks are said to have (but they really can't promise this) a 3 million hour MTBF. Thanks, Nick shadowym wrote: The cold hard truth is that if Asterisk cannot achieve 99.999% uptime without becoming much more expensive that a traditional PBX then it is not a viable alternative. Even elcheapo Key systems are rated for five nines. That is what the telco world requires unless your just using Asterisk in your basement as a hobby or as a one man company. Redundant Servers is moving into the realm of non-competitive with Traditional PBX IMHO. I don't care about corruption of the CDR or any of the logging/database information. All I care about is the ability make phone calls after power failure. That IS the MAIN function of a PBX. Not call centers, databases, CDR, click 2 call, and all the other bells and whistles. -Original Message- From: Boris Bakchiev [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 2:13 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: RE: [Asterisk-Users] Hard drive write cache These days you don't have to worry much about your write cache unless you're running application where once single byte changed will affect whole file. Look at it this way, the only corruption will occur is whatever the files were open by asterisk at the time of the crash. And only up to the point where the file was last open. As far as I know asterisk does not keep cdr or log files open so you would loose only the data that was written at the time of the power failure. Any journaling file system (ext3, resierfs, xfs, etc) will easily handle any power failure event. Your files will not be corrupt but could miss some of the data. At the most you will loose 10-50 cdr entries written to you log files. If you post CDR to a remote SQL database then you asterisk install and linux is more or less static and will not be affected by the power failure. What you need to do is minimise the writes to hard disk's: 1 - Send syslog to remote server and do not do ANY syslogs Or keep the circular buffer in memory if you have plenty of it. 2 - Send CDR's to SQL server (or log to ramdisk and send to remote server every few minutes via SSH) 3 - Do not record any calls (or do that somewhere else) 4 - Stop any services that write/read data on regular intervals. If you have no writes you have nothing to worry about during power failure and journaling file system will take care of the rest. Keep your partition size really small so that fsck will not take much time. You have to be realistic, you cannot achieve 99.999% uptime. That's 5 minutes per year downtime. You will have more or less 100% until your first hardware failure. Even if you have all the hardware components pre-purchased it will still take you 2-12 hours to detect, diagnose and fix the fault if you lucky. So your 5 minuets If the business is demanding 99.999% then it should be prepared to invest into the hardware. I would recommend a cluster or even better a fault tolerant server. Those are expensive but you can pretty much rule out the hardware failure and swap all of the failed components while the system is running (cpu, memory, hdd, etc). Look at Stratus or NEC FT servers if you need hardware redundancy. They're expensive but will give you the hardware reliability you need. Or get a traditional PABX :) -Original Message- From: [EMAIL PROTECTED] [mailto:asterisk-users- [EMAIL PROTECTED] On Behalf Of shadowym Sent: Tuesday, 13 June 2006 10:34 To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] Hard drive write cache I am looking at ways to harden my asterisk install to prevent computer related issues from happening. I am concerned about about disk write cache. That seems to be a major source of hard drive corruption on power failure. Hard Drive corruption is simply unacceptable for the 99.999% uptime requirements of my Asterisk install that needs to be as reliable as a proprietary PBX. Of course I will be using redundant power supplies, raid 1 and use a UPS. None of those things mean much if the power
RE: [Asterisk-Users] Hard drive write cache
Thanks for the suggestions. CF is not an option for FreePBX which is a requirement for the installs I have in mind. Astlinux on CF is a great option otherwise. That is by far the simplest, cheapest, and suprisingly most reliable solution I have come across so far. If there was a half decent (open source) GUI that could run on Astlinux on CF it would be a no brainer IMHO. Physically locking down the server is not an option. It will be hung on the wall in place of where a traditional PBX would normally go. This is a telecom closet NOT a server rack environment. UPS with auto shut down is just one link in the chain. Do you have any further information of locking plugs? I have not come across those before. Of course in order for that to make sense I would need locking plugs on both the server AND UPS end. It has to be idiot proof. Think PBX and/or network appliance not computer server. They are idiot proof so it is quite reasonable IMHO to expect the same from an Asterisk server (or in my way of thinking, Asterisk network appliance). -Original Message- From: Nicholas Kathmann [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 11:04 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Hard drive write cache If all you are worried about is the write cache on the disks, why not just put the system on a UPS set to shutdown the system in the event of power failure, then place both the UPS and asterisk servers in a locked rack. In the event of a power failure (or someone knocking the plug loose, which you can use locking plugs to further mitigate), the system will stay up on battery power then shut itself down to prevent data corruption. I doubt you will get that level of uptime, but there are other options to help achieve higher reliability. You can run the OS and asterisk on a solid state disk, and have voicemail and whatever else you want to go to rotating disks. That will also help with power usage on the server when using the UPS. Industrial flash disks are said to have (but they really can't promise this) a 3 million hour MTBF. Thanks, Nick shadowym wrote: The cold hard truth is that if Asterisk cannot achieve 99.999% uptime without becoming much more expensive that a traditional PBX then it is not a viable alternative. Even elcheapo Key systems are rated for five nines. That is what the telco world requires unless your just using Asterisk in your basement as a hobby or as a one man company. Redundant Servers is moving into the realm of non-competitive with Traditional PBX IMHO. I don't care about corruption of the CDR or any of the logging/database information. All I care about is the ability make phone calls after power failure. That IS the MAIN function of a PBX. Not call centers, databases, CDR, click 2 call, and all the other bells and whistles. -Original Message- From: Boris Bakchiev [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 2:13 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: RE: [Asterisk-Users] Hard drive write cache These days you don't have to worry much about your write cache unless you're running application where once single byte changed will affect whole file. Look at it this way, the only corruption will occur is whatever the files were open by asterisk at the time of the crash. And only up to the point where the file was last open. As far as I know asterisk does not keep cdr or log files open so you would loose only the data that was written at the time of the power failure. Any journaling file system (ext3, resierfs, xfs, etc) will easily handle any power failure event. Your files will not be corrupt but could miss some of the data. At the most you will loose 10-50 cdr entries written to you log files. If you post CDR to a remote SQL database then you asterisk install and linux is more or less static and will not be affected by the power failure. What you need to do is minimise the writes to hard disk's: 1 - Send syslog to remote server and do not do ANY syslogs Or keep the circular buffer in memory if you have plenty of it. 2 - Send CDR's to SQL server (or log to ramdisk and send to remote server every few minutes via SSH) 3 - Do not record any calls (or do that somewhere else) 4 - Stop any services that write/read data on regular intervals. If you have no writes you have nothing to worry about during power failure and journaling file system will take care of the rest. Keep your partition size really small so that fsck will not take much time. You have to be realistic, you cannot achieve 99.999% uptime. That's 5 minutes per year downtime. You will have more or less 100% until your first hardware failure. Even if you have all the hardware
Re: [Asterisk-Users] Hard drive write cache
On Tuesday 13 June 2006 15:36, shadowym wrote: Physically locking down the server is not an option. It will be hung on the wall in place of where a traditional PBX would normally go. This is a telecom closet NOT a server rack environment. UPS with auto shut down is just one link in the chain. Do you have any further information of locking plugs? I have not come across those before. Of course in order for that to make sense I would need locking plugs on both the server AND UPS end. It has to be idiot proof. Almost every telco closet I have been in (anything from 5-person accounting firm to 750 person manufacturing facility for Honda) has had a telco closet with a lock on the door. Sometimes this closet was little more than a space under the stairs to the basement and behind the water heater and 6 years of records, but the access was physically restricted. Also, my Norstar MICS upstairs doesn't have locking plugs. It's on a UPS that does not notify it of impending doom, and it comes back up just fine most of the time[1]. My Linux firewall is under the same constraints and also comes up fine. Why are you giving such heavy requirements for your particular application? What's wrong with a readonly / and RAM drive /var and /tmp? Store configs and voicemail on a flash drive or even a journalled filesystem on a hard drive mounted synchronously. [1] Ask any Norstar user how often Flash takes a big shit when it loses power. And there is no way to notify it. I'd say at least 5-10% of the time it has some problem, ranging from stuck voicemail to corrupted voicemail to rare (but often enough) occurances wherein you have to reinitialize the entire Flash voicemail system! Think PBX and/or network appliance not computer server. They are idiot proof so it is quite reasonable IMHO to expect the same from an Asterisk server (or in my way of thinking, Asterisk network appliance). I think you're aiming for too high a grade of idiot. Any standard fanless PC can achieve the kinds of uptimes you want from your typical NEC Electra Elite or Norstar MICS without resorting to the kind of circus act you're doing here. -A. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] Hard drive write cache
They have IDE and even some SATA (not easily available) flash drives also, some of which are over 80GB. The more space you get, the quicker it goes up in price with the larger models costing more than most servers. If you want, you can also use an IDE to CF adapter. For the locking plugs, google NEMA-L5 or NEMA-L6 and that will show you what they look like. They are readily available in most hardware stores for low cost. On the server side, you can tie wrap the power cable to the rail or something like that, but I would suggest just getting a server that has the thumbscrew and clamp to hold the power cord in place. They are available on most IBM servers. If the power cord is mounted to the wall with staples or those nail in C clamps, someone would have to go out of their way to pull the power cord out. Another option if it's a really small installation is to use a mini-itx fanless system. We have 2 set up here (in a test lab for now) with 1Ghz Via processors running up to ten (that's all we've tried) concurrent calls with no problems. These is no transcoding and echo cancellation running on these. Next it to try some Digium and Sangoma PCI cards in them and see how they work. I'll post the results when we finish. Such systems are extremely reliable as long as you don't pull too much from the small power supplies, etc. Regardless of what you use or what you do, trying to achieve 5 nines reliability is going to require a whole rack full of systems, storage, batteries, etc and a whole lot of configuration and testing. Even PBX systems (not all) require downtime for firmware upgrades, etc. Most people don't bother since the systems aren't connected to data networks. It was actually easier to pull the power cables out of some of the PBX equipment (such as the Definity G3si) than it is to pull the equipment out of the Cisco VoIP or IBM servers combined with the right PDUs, etc. Thanks, Nick shadowym wrote: Thanks for the suggestions. CF is not an option for FreePBX which is a requirement for the installs I have in mind. Astlinux on CF is a great option otherwise. That is by far the simplest, cheapest, and suprisingly most reliable solution I have come across so far. If there was a half decent (open source) GUI that could run on Astlinux on CF it would be a no brainer IMHO. Physically locking down the server is not an option. It will be hung on the wall in place of where a traditional PBX would normally go. This is a telecom closet NOT a server rack environment. UPS with auto shut down is just one link in the chain. Do you have any further information of locking plugs? I have not come across those before. Of course in order for that to make sense I would need locking plugs on both the server AND UPS end. It has to be idiot proof. Think PBX and/or network appliance not computer server. They are idiot proof so it is quite reasonable IMHO to expect the same from an Asterisk server (or in my way of thinking, Asterisk network appliance). -Original Message- From: Nicholas Kathmann [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 11:04 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Hard drive write cache If all you are worried about is the write cache on the disks, why not just put the system on a UPS set to shutdown the system in the event of power failure, then place both the UPS and asterisk servers in a locked rack. In the event of a power failure (or someone knocking the plug loose, which you can use locking plugs to further mitigate), the system will stay up on battery power then shut itself down to prevent data corruption. I doubt you will get that level of uptime, but there are other options to help achieve higher reliability. You can run the OS and asterisk on a solid state disk, and have voicemail and whatever else you want to go to rotating disks. That will also help with power usage on the server when using the UPS. Industrial flash disks are said to have (but they really can't promise this) a 3 million hour MTBF. Thanks, Nick shadowym wrote: The cold hard truth is that if Asterisk cannot achieve 99.999% uptime without becoming much more expensive that a traditional PBX then it is not a viable alternative. Even elcheapo Key systems are rated for five nines. That is what the telco world requires unless your just using Asterisk in your basement as a hobby or as a one man company. Redundant Servers is moving into the realm of non-competitive with Traditional PBX IMHO. I don't care about corruption of the CDR or any of the logging/database information. All I care about is the ability make phone calls after power failure. That IS the MAIN function of a PBX. Not call centers, databases, CDR, click 2 call, and all the other bells and whistles
RE: [Asterisk-Users] Hard drive write cache
[1] Ask any Norstar user how often Flash takes a big shit when it loses power. lol...snap! aaahhh the memories. Makes the Asterisk burn seem minor by comparision. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] Hard drive write cache
Hi Andrew, I think we are more on the same page than you think. Fanless PC and CF are exactly what I am shooting for. However, as far as I know you need a hard drive to run FreePBX. Read only partitions make a lot of sense and I will certainly pursue that further. Not sure if I would need to put Voicemail on a CF if I have a hard drive. I could care less if someones voicemail messages get corrupted during a power outage. All I want is for the phone system to come back up and work again. GUARANTEED! -Original Message- From: Andrew Kohlsmith [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 1:12 PM To: asterisk-users@lists.digium.com Subject: Re: [Asterisk-Users] Hard drive write cache On Tuesday 13 June 2006 15:36, shadowym wrote: Physically locking down the server is not an option. It will be hung on the wall in place of where a traditional PBX would normally go. This is a telecom closet NOT a server rack environment. UPS with auto shut down is just one link in the chain. Do you have any further information of locking plugs? I have not come across those before. Of course in order for that to make sense I would need locking plugs on both the server AND UPS end. It has to be idiot proof. Almost every telco closet I have been in (anything from 5-person accounting firm to 750 person manufacturing facility for Honda) has had a telco closet with a lock on the door. Sometimes this closet was little more than a space under the stairs to the basement and behind the water heater and 6 years of records, but the access was physically restricted. Also, my Norstar MICS upstairs doesn't have locking plugs. It's on a UPS that does not notify it of impending doom, and it comes back up just fine most of the time[1]. My Linux firewall is under the same constraints and also comes up fine. Why are you giving such heavy requirements for your particular application? What's wrong with a readonly / and RAM drive /var and /tmp? Store configs and voicemail on a flash drive or even a journalled filesystem on a hard drive mounted synchronously. [1] Ask any Norstar user how often Flash takes a big shit when it loses power. And there is no way to notify it. I'd say at least 5-10% of the time it has some problem, ranging from stuck voicemail to corrupted voicemail to rare (but often enough) occurances wherein you have to reinitialize the entire Flash voicemail system! Think PBX and/or network appliance not computer server. They are idiot proof so it is quite reasonable IMHO to expect the same from an Asterisk server (or in my way of thinking, Asterisk network appliance). I think you're aiming for too high a grade of idiot. Any standard fanless PC can achieve the kinds of uptimes you want from your typical NEC Electra Elite or Norstar MICS without resorting to the kind of circus act you're doing here. -A. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] Hard drive write cache
You still need a hard drive to run FreePBX as far as I know. Either that or burn out your 2GB CF drive after a couple months of constant writes. I would assume Apache and MySQL would need to go on the HD. Voicemail can go there as well. Linux/Asterisk binaries and base config files can probably go on the CF read only. Would this work? Are there any how-to's around that have done something like this? It is starting to make a bit more sense to me to do it this way but I'm no expert. If I did it this way I would not have a need for RAID so it will probably come out to about the same price. -Original Message- From: Nicholas Kathmann [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 1:22 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Hard drive write cache They have IDE and even some SATA (not easily available) flash drives also, some of which are over 80GB. The more space you get, the quicker it goes up in price with the larger models costing more than most servers. If you want, you can also use an IDE to CF adapter. For the locking plugs, google NEMA-L5 or NEMA-L6 and that will show you what they look like. They are readily available in most hardware stores for low cost. On the server side, you can tie wrap the power cable to the rail or something like that, but I would suggest just getting a server that has the thumbscrew and clamp to hold the power cord in place. They are available on most IBM servers. If the power cord is mounted to the wall with staples or those nail in C clamps, someone would have to go out of their way to pull the power cord out. Another option if it's a really small installation is to use a mini-itx fanless system. We have 2 set up here (in a test lab for now) with 1Ghz Via processors running up to ten (that's all we've tried) concurrent calls with no problems. These is no transcoding and echo cancellation running on these. Next it to try some Digium and Sangoma PCI cards in them and see how they work. I'll post the results when we finish. Such systems are extremely reliable as long as you don't pull too much from the small power supplies, etc. Regardless of what you use or what you do, trying to achieve 5 nines reliability is going to require a whole rack full of systems, storage, batteries, etc and a whole lot of configuration and testing. Even PBX systems (not all) require downtime for firmware upgrades, etc. Most people don't bother since the systems aren't connected to data networks. It was actually easier to pull the power cables out of some of the PBX equipment (such as the Definity G3si) than it is to pull the equipment out of the Cisco VoIP or IBM servers combined with the right PDUs, etc. Thanks, Nick shadowym wrote: Thanks for the suggestions. CF is not an option for FreePBX which is a requirement for the installs I have in mind. Astlinux on CF is a great option otherwise. That is by far the simplest, cheapest, and suprisingly most reliable solution I have come across so far. If there was a half decent (open source) GUI that could run on Astlinux on CF it would be a no brainer IMHO. Physically locking down the server is not an option. It will be hung on the wall in place of where a traditional PBX would normally go. This is a telecom closet NOT a server rack environment. UPS with auto shut down is just one link in the chain. Do you have any further information of locking plugs? I have not come across those before. Of course in order for that to make sense I would need locking plugs on both the server AND UPS end. It has to be idiot proof. Think PBX and/or network appliance not computer server. They are idiot proof so it is quite reasonable IMHO to expect the same from an Asterisk server (or in my way of thinking, Asterisk network appliance). -Original Message- From: Nicholas Kathmann [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 13, 2006 11:04 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Hard drive write cache If all you are worried about is the write cache on the disks, why not just put the system on a UPS set to shutdown the system in the event of power failure, then place both the UPS and asterisk servers in a locked rack. In the event of a power failure (or someone knocking the plug loose, which you can use locking plugs to further mitigate), the system will stay up on battery power then shut itself down to prevent data corruption. I doubt you will get that level of uptime, but there are other options to help achieve higher reliability. You can run the OS and asterisk on a solid state disk, and have voicemail and whatever else you want to go to rotating disks. That will also help with power
RE: [Asterisk-Users] Hard drive write cache
The cold hard truth is that if Asterisk cannot achieve 99.999% uptime without becoming much more expensive that a traditional PBX then it is not a viable alternative. Even elcheapo Key systems are rated for five nines. That is what the telco world requires unless your just using Asterisk in your basement as a hobby or as a one man company. Well, you can pretty much guarantee 100% software uptime with asterisk. The main causes of crashes of the working system are users. If it works... don't touch it, do not logon to it... forget about it. Create a minimalistic root system with busybox, have everything on CF on IDE adapter, user UPS with shutdown to protect the CF (as they're prone to failures on power loss) and you have yourself a VERY stable system. You can use JFFS2 on block device to reduce the wear on CF but you will not need it if you're not writing anything on CF (or have 2 CF's and md them together.) I have never seen PBX with guarantee of 99.999%. None of the manufacturers will commit to that unless it is a highly redundant system, but by then it's not elcheapo. About fanless PC's.. A stock standard intel fan would lust longer then you think unless its located in dusty and damp place. I have a p3 that's been running for 5 years non-stop and it was still going strong.. Half the capacitors started to leak on the motherboard but the fan was still spinning. :) Now that's reliability! Redundant Servers is moving into the realm of non-competitive with Traditional PBX IMHO. More or less true. Any 100-200 extension highly redundant PBX system will costs you more or less the same money. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] Hard drive write cache
Raid card with an onboard battery backup. PaulH -- Paul Hales Technical Manager AsteriskIT www.asteriskit.com.au bus: 03 8320 8100 mob: 0434 673 529 shadowym wrote: I am looking at ways to harden my asterisk install to prevent computer related issues from happening. I am concerned about about disk write cache. That seems to be a major source of hard drive corruption on power failure. Hard Drive corruption is simply unacceptable for the 99.999% uptime requirements of my Asterisk install that needs to be as reliable as a proprietary PBX. Of course I will be using redundant power supplies, raid 1 and use a UPS. None of those things mean much if the power cords accidentally get pulled from the back of the server. Unlikely as it may be I have to consider ALL possibilities. So is disabling the write cache a good way to reduce the risk of hard drive corruption for an Asterisk server? I am not too concerned about the reduced performance/lifetime of hardrives with write cache disabled since Asterisk is not a very write intensive environment. Even with lot's of voicemail going on. Any other recommendations/links for increasing the reliability of Asterisk servers? ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] Hard drive write cache
shadowym wrote: Any other recommendations/links for increasing the reliability of Asterisk servers? Separate the various use cases of the filesystem into different volumes with LVM. The parts that are not written to except during upgrades like /usr should be mounted read-only, and the various read/write sections like /var/spool/asterisk and /var/log should be on separate volumes also. This keeps any corruption experienced localized to a small area, and keeps your binaries unquestionably safe from a power outage and the only step needed is automated detection and cleanup of the read/write volumes. Write barriers allow you to keep write-cache turned on in the drives, and sends a command to the drive to reply when the data hits the platters. Also if the drive doesn't support that, various techniques are used to verify the data is on the media and not in drive cache. Contact your distro support company and ask them if write-barriers have been implemented in the drivers for the drive controllers you are using, and if not, then either buy the hardware that does support that or sponsor them to update the driver to support write-barriers. Also contact your distro support company to see if they have any recommendations for the setup you want. Mike ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
