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On 21/07/13 22:31, luis jure wrote: |
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> |
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> OK, now i have my system successfully installed and running on my new SSD. |
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> now i have to decide what to do with the rest of the disk (it's a 256MB |
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> samsung). |
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> |
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> the first big question is: what about swap? i found some web pages |
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> (perhaps old) stating that it's not wise to put swap on the SSD because of |
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> all the read/writes. but apparently from what i read on the recent |
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> thread on this list, that shouldn't be much of a concern now. |
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> |
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> i also read somewhere that if you have swap on the SSD and want to avoid |
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> unnecessary read/writes, you can reduce swappiness. i have 12GB RAM and i |
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> think normally i don't really need swap space on disk, so i thought that |
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> could be a good idea. |
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> |
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> so what i'm planning to do now is: |
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> |
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> - put swap on the SSD |
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> - reduce swappiness |
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> - put /var/tmp/portage on tmpfs |
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> |
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> so, do you guys think that's a good setup? |
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> |
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swap: this will make one of the bigger speedups to the system when you |
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need swap. swap is good - yes you can do without it, but the day comes |
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when you REALLY do want it, and ... [crash!] ... otherwise it can just |
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sit there waiting :) |
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/etc/sysctl.conf: |
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#vm.swappiness=1 |
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#vm.vfs_cache_pressure=50 |
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these were recommended to me for running vm's and seem to do the job |
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(usually I am running with a several GB of swap (16G ram, 16G swap) in |
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use ... these settings definitely minimise it though big rsync jobs |
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stall when it fills ram+swap. |
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/var/tmp/portage is a more difficult one ... a long thread way back |
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(Dale, I think you were in it) looking at speed showed there was no |
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speed advantage to compiling in tempfs because spinner) disk caching was |
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so good the data only hit the disk when necessary. I presume the same |
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will apply with compiling and SSD's in that the actual writes will be |
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minimal (in the scheme of things) so it shouldn't be a worry. My |
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experience with compiling in tempfs is that it works, but has a much |
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higher failure rate than on disk - i.e., things like OO/Lo, KDE, gcc and |
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glibc have large space requirements that you must make sure tmpfs can |
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satisfy before you start. And if its a busy machine actively using lots |
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of ram it gets "hard". I am making the point that most machines today |
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are way overprovisioned but when you are near the edge, saying things |
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like I gave xGB ram and never needed swap, so you wont either is |
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misrepresenting the situation. |
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BillK |
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