Re: Postfix queue on ramdisk: Insufficient system storage
* Stan Hoeppner s...@hardwarefreak.com: Wietse Venema put forth on 7/21/2010 2:22 PM: Ram: One server of ours just accepts the mails from clients and then relays the mails to other servers. Since there is almost no mail queued on the server , I think it is will be good to mount /var/spool/postfix on a tmpfs partition. You will lose all mail in the queue when the system crashes. I agree with Victor that this is a really bad idea. +3 If you truly have a _need_ for a super fast Postfix queue, I suggest using a good quality wear leveling SSD. You'll get random I/O performance many times greater than a 15k rpm disk, but with data persistence, unlike when using a ramdisk queue. There are many fast good quality SSDs available in various capacities for between $100-200 USD, in standard 2.5 and 3.5 hard disk mounting form factors. You can get about 150 msg/sec a 100k on a single Postfix instance if you use a set of 10k rpm discs in a RAID 0 and server hardware. p...@rick -- All technical questions asked privately will be automatically answered on the list and archived for public access unless privacy is explicitely required and justified. saslfinger (debugging SMTP AUTH): http://postfix.state-of-mind.de/patrick.koetter/saslfinger/
Re: Postfix queue on ramdisk: Insufficient system storage
Patrick Ben Koetter put forth on 7/22/2010 2:11 AM: * Stan Hoeppner s...@hardwarefreak.com: Wietse Venema put forth on 7/21/2010 2:22 PM: Ram: One server of ours just accepts the mails from clients and then relays the mails to other servers. Since there is almost no mail queued on the server , I think it is will be good to mount /var/spool/postfix on a tmpfs partition. You will lose all mail in the queue when the system crashes. I agree with Victor that this is a really bad idea. +3 If you truly have a _need_ for a super fast Postfix queue, I suggest using a good quality wear leveling SSD. You'll get random I/O performance many times greater than a 15k rpm disk, but with data persistence, unlike when using a ramdisk queue. There are many fast good quality SSDs available in various capacities for between $100-200 USD, in standard 2.5 and 3.5 hard disk mounting form factors. You can get about 150 msg/sec a 100k on a single Postfix instance if you use a set of 10k rpm discs in a RAID 0 and server hardware. If my math is correct, I believe Ram's relay server has a queue load of less than 15 msg/sec on average, which is easily handled by a single SATA disk. 50,000/hr = 50,000/3600 = 13.88 msg/sec Ram, why are you considering ramdisk or SSD for your Postfix queues given that a regular disk would seem to handle your load rather easily? Or, is this more of a philosophical issue of not wanting to write anything to disk that isn't permanent? -- Stan
Re: Postfix queue on ramdisk: Insufficient system storage
On Thu, 2010-07-22 at 04:50 -0500, Stan Hoeppner wrote: Patrick Ben Koetter put forth on 7/22/2010 2:11 AM: * Stan Hoeppner s...@hardwarefreak.com: Wietse Venema put forth on 7/21/2010 2:22 PM: Ram: One server of ours just accepts the mails from clients and then relays the mails to other servers. Since there is almost no mail queued on the server , I think it is will be good to mount /var/spool/postfix on a tmpfs partition. You will lose all mail in the queue when the system crashes. I agree with Victor that this is a really bad idea. +3 If you truly have a _need_ for a super fast Postfix queue, I suggest using a good quality wear leveling SSD. You'll get random I/O performance many times greater than a 15k rpm disk, but with data persistence, unlike when using a ramdisk queue. There are many fast good quality SSDs available in various capacities for between $100-200 USD, in standard 2.5 and 3.5 hard disk mounting form factors. You can get about 150 msg/sec a 100k on a single Postfix instance if you use a set of 10k rpm discs in a RAID 0 and server hardware. If my math is correct, I believe Ram's relay server has a queue load of less than 15 msg/sec on average, which is easily handled by a single SATA disk. 50,000/hr = 50,000/3600 = 13.88 msg/sec Ram, why are you considering ramdisk or SSD for your Postfix queues given that a regular disk would seem to handle your load rather easily? Or, is this more of a philosophical issue of not wanting to write anything to disk that isn't permanent? You are right. If Postfix alone was running on this server will be able to handle (50k-70k msgs/hr) with the given I/O. But there are other custom functions running on this machine. I was just considering ramdisk , because that was the laziest way I could get rid of unnecessary IOPS to disk. Anyway I think I will go by what all you folk say. No ramdisk for postfix. Thanks for the inputs. Ram
Re: Postfix queue on ramdisk: Insufficient system storage
Ram: One server of ours just accepts the mails from clients and then relays the mails to other servers. Since there is almost no mail queued on the server , I think it is will be good to mount /var/spool/postfix on a tmpfs partition. The machine ( linux Centos 5.4 + postfix 2.7 ) has enough Memory free all the time. The ramdisk seems to work great. But sporadically some smtp clients are getting an error Insufficient system storage When will this happen ? Look in your maillog file, and perhaps in your KERNEL log. Does postfix find not enough space on the ramdisk ? The KERNEL looks for space, not Postfix. Do not blame the messenger (Postfix) for bad news from the kernel. Wietse
Re: Postfix queue on ramdisk: Insufficient system storage
On Wed, Jul 21, 2010 at 06:39:07AM -0400, Wietse Venema wrote: One server of ours just accepts the mails from clients and then relays the mails to other servers. Since there is almost no mail queued on the server , I think it is will be good to mount /var/spool/postfix on a tmpfs partition. [ Following up on the OP's post second-hand, not Wietse's ] Also don't ask for trouble (memory exhaustion and/or email loss) by running Postfix on ramdisk. It is not a good idea. Your intuition about the value of this is misguided. -- Viktor.
Re: Postfix queue on ramdisk: Insufficient system storage
Ram: One server of ours just accepts the mails from clients and then relays the mails to other servers. Since there is almost no mail queued on the server , I think it is will be good to mount /var/spool/postfix on a tmpfs partition. You will lose all mail in the queue when the system crashes. I agree with Victor that this is a really bad idea. Wietse
Re: Postfix queue on ramdisk: Insufficient system storage
Wietse Venema put forth on 7/21/2010 2:22 PM: Ram: One server of ours just accepts the mails from clients and then relays the mails to other servers. Since there is almost no mail queued on the server , I think it is will be good to mount /var/spool/postfix on a tmpfs partition. You will lose all mail in the queue when the system crashes. I agree with Victor that this is a really bad idea. +3 If you truly have a _need_ for a super fast Postfix queue, I suggest using a good quality wear leveling SSD. You'll get random I/O performance many times greater than a 15k rpm disk, but with data persistence, unlike when using a ramdisk queue. There are many fast good quality SSDs available in various capacities for between $100-200 USD, in standard 2.5 and 3.5 hard disk mounting form factors. -- Stan
