> Does anybody really want to wait while their swap data is duplicated
> out to multiple disks by a CPU that is working to free up memory to
> run applications?
>
> Isn't Swapping slow enough already?
>
> Why not simply swap on multiple disks, get Hardware RAID-5 for swap
> or buy RAM?
>
If ANY
"m. allan noah" wrote:
>
> no. just to recap the discussion that has been occurring on and off this list
> as i understand it:
>
> 1. it is NOT safe to swap to a raid partition while reconstuction is occuring.
>the general consensus is that this is true whether or not the swap
>partition
no. just to recap the discussion that has been occurring on and off this list
as i understand it:
1. it is NOT safe to swap to a raid partition while reconstuction is occuring.
the general consensus is that this is true whether or not the swap
partition is the one syncing. therefor, most fo
On Thu, 1 Jun 2000, Henry J. Cobb wrote:
> Does anybody really want to wait while their swap data is duplicated out to
> multiple disks by a CPU that is working to free up memory to run
> applications?
>
> Isn't Swapping slow enough already?
>
> Why not simply swap on multiple disks, get Hardwa
Well, the reason we have our systems set to swap on RAID (we use RAID-1) is
that this improves our robustness. Even if one of our disks dies then the
swap continues to work and the system is still stable. Also, I believe, it
is possible to use a RAID-10 to stripe and mirror and actually improve swa
On Tue, Jan 04, 2000 at 05:35:19PM -0800, Michael wrote:
> Could the Raid experts revisit a portion of the discussion about swap
> on raid. I understand that the use/non-use of buffer space during
> reconsturction vs swap creates a problem for swap on raid, however in
> my pea-sized brain it ap
On Wed, 14 Jul 1999, Roeland M.J. Meyer wrote:
I think that he's talking about RAID10. Take two RAID1 devices and bond
them with RAID0.
no i think he means two seperate raid1 md devices for swap. raid10
would be even more overhead imo - but if anyone has empirical
evidence i'd love to see it
> I think it is possible to create swap 'spaces' larger than 128M, but it
> will only take advantage of the first 128M (but I can't find an exact
> answer in the kernel right now). Can you point me to a page or kernel
> source that says you can use more that 128M, I can't find it. Thanks.
Check
Helge Hafting wrote:
>
> > I think it is possible to create swap 'spaces' larger than 128M, but it
> > will only take advantage of the first 128M (but I can't find an exact
> > answer in the kernel right now). Can you point me to a page or kernel
> > source that says you can use more that 128M,
> I think it is possible to create swap 'spaces' larger than 128M, but it
> will only take advantage of the first 128M (but I can't find an exact
> answer in the kernel right now). Can you point me to a page or kernel
> source that says you can use more that 128M, I can't find it. Thanks.
You
Marc Mutz wrote:
>
> MadHat wrote:
> >
> > A James Lewis wrote:
> > >
> > > I don't think the 128Meg swap limit applies any more!
> > >
> >
> > I think it is possible to create swap 'spaces' larger than 128M, but it
> > will only take advantage of the first 128M (but I can't find an exact
> > ans
MadHat wrote:
>
> A James Lewis wrote:
> >
> > I don't think the 128Meg swap limit applies any more!
> >
>
> I think it is possible to create swap 'spaces' larger than 128M, but it
> will only take advantage of the first 128M (but I can't find an exact
> answer in the kernel right now). Can you
: [EMAIL PROTECTED]
Subject: Re: Swap on Raid ???
A James Lewis wrote:
>
> I don't think the 128Meg swap limit applies any more!
>
I think it is possible to create swap 'spaces' larger than 128M, but it
will only take advantage of the first 128M (but I can't find an exa
A James Lewis wrote:
>
> I don't think the 128Meg swap limit applies any more!
>
I think it is possible to create swap 'spaces' larger than 128M, but it
will only take advantage of the first 128M (but I can't find an exact
answer in the kernel right now). Can you point me to a page or kernel
so
I don't think the 128Meg swap limit applies any more!
On 15 Jul 1999, Osma Ahvenlampi wrote:
> Paul Jakma <[EMAIL PROTECTED]> writes:
> > well, i'm just testing at the moment to see if it's feasible. Anyway,
> > i never mentioned an amount of swap, i didn't say anything about
> > 384mb. I actu
Paul Jakma <[EMAIL PROTECTED]> writes:
> well, i'm just testing at the moment to see if it's feasible. Anyway,
> i never mentioned an amount of swap, i didn't say anything about
> 384mb. I actually have 4 partitions of 40MB = 160MB total. After
> RAID5 -> 120MB, which is reasonable.
Funny, you sh
tz
> Sent: Wednesday, July 14, 1999 2:48 PM
> To: [EMAIL PROTECTED]
> Cc: Paul Jakma; Osma Ahvenlampi; Joel Fowler;
> [EMAIL PROTECTED]
> Subject: Re: Swap on Raid ???
>
>
> Roeland M.J. Meyer wrote:
> >
>
> > > RAID-1 is faster? since when? RAID-5 should
Roeland M.J. Meyer wrote:
>
> > RAID-1 is faster? since when? RAID-5 should be faster at reads. I get
> > ~25MB/s sustained read across 4 U/W disks, 16MB/s sustained write
> > according to bonnie. (i've never tried RAID-1 to be honest).
>
> I think that he's talking about RAID10. Take two RAID1
> [mailto:[EMAIL PROTECTED]]On Behalf Of Paul Jakma
> Sent: Wednesday, July 14, 1999 10:01 AM
> To: Osma Ahvenlampi
>
> On 14 Jul 1999, Osma Ahvenlampi wrote:
>
> Paul Jakma <[EMAIL PROTECTED]> writes:
> > with RAID1 i have 1/2 the physical space available for swap.
> > with RAID5 i have 3/4
On 14 Jul 1999, Osma Ahvenlampi wrote:
Paul Jakma <[EMAIL PROTECTED]> writes:
> with RAID1 i have 1/2 the physical space available for swap.
> with RAID5 i have 3/4 of physical space available for swap.
> hence i choose RAID5.
> seems a lot more efficient to me.
Space-efficient
> [mailto:[EMAIL PROTECTED]]On Behalf Of
> Jonathan F. Dill
> Sent: Tuesday, July 13, 1999 5:20 PM
>
> AFAIK unless you've done something to the kernel to get around that
> limit. What's the point of running swap on RAID anyway? Memory is
> cheap these days--seems to me rather than wasting time
Paul Jakma <[EMAIL PROTECTED]> writes:
> with RAID1 i have 1/2 the physical space available for swap.
> with RAID5 i have 3/4 of physical space available for swap.
> hence i choose RAID5.
> seems a lot more efficient to me.
Space-efficient, yes, speed-efficient, certainly not. Are you
absolut
On Tue, 13 Jul 1999, Jonathan F. Dill wrote:
Without RAID or with RAID-0 you have 4/4 of the physical space
available for swap. The maximum size for a linux swap space is ~127 MB
AFAIK unless you've done something to the kernel to get around that
limit.
that limit is gone up in 2.2. N
Paul Jakma wrote:
>
> On Tue, 13 Jul 1999, Marc Mutz wrote:
>
> Why does anybody want to use swap-on-RAID with any RAID level than 1?
> Wouldn't it be much faster if you used multiple swap spaces?
>
> Marc
>
> cause i have 4 partitions dedicated to swap. with raid-1 i have only
> 1/5 the
> On Tue, 13 Jul 1999, Marc Mutz wrote:
>
> Why does anybody want to use swap-on-RAID with any RAID level
> than 1? Wouldn't it be much faster if you used multiple swap
> spaces?
>
Pretty simple. If your swap space becomes corrupted or you lose the
disk it resides on, the kernel
On Tue, 13 Jul 1999, Paul Jakma wrote:
On Tue, 13 Jul 1999, Marc Mutz wrote:
Why does anybody want to use swap-on-RAID with any RAID level than 1?
Wouldn't it be much faster if you used multiple swap spaces?
Marc
cause i have 4 partitions dedicated to swap. with raid-
On Tue, 13 Jul 1999, Marc Mutz wrote:
Why does anybody want to use swap-on-RAID with any RAID level than 1?
Wouldn't it be much faster if you used multiple swap spaces?
Marc
cause i have 4 partitions dedicated to swap. with raid-1 i have only
1/5 the space available to use for swap. W
Why does anybody want to use swap-on-RAID with any RAID level than 1?
Wouldn't it be much faster if you used multiple swap spaces?
Marc
--
Marc Mutz <[EMAIL PROTECTED]>http://marc.mutz.com/
University of Bielefeld, Dep. of Mathematics / Dep. of Physics
PGP-keyID's: 0xd46c
On Mon, 12 Jul 1999 [EMAIL PROTECTED] wrote:
> The HOWTO states that swapping on RAID is unsafe, and that is probably
> unjustified with the latest RAID patches.
yes swapping is safe. It's _slightly_ justified with RAID1 to be fair -
but i've tried it myself and was unable to reproduce anything
On Mon, 12 Jul 1999, Paul Jakma wrote:
> On Mon, 12 Jul 1999, Joel Fowler wrote:
>
> Now, I would like to raid-1 my swap partition for high-availability. I
> read in the Software-Raid-HOWTO that as of 2.0.x that it wasn't supported
> and would cause crashes. Is that still the case with t
On Mon, 12 Jul 1999, Joel Fowler wrote:
Now, I would like to raid-1 my swap partition for high-availability. I
read in the Software-Raid-HOWTO that as of 2.0.x that it wasn't supported
and would cause crashes. Is that still the case with the 2.2.5-22 kernel?
If it will work, is there a
On Mon, Jul 12, 1999 at 01:59:46PM -0700, Joel Fowler wrote:
> I use RedHat 6.0 with a 2.2.5-22 kernel and raid-tools-0.90.
>
> I have just configured and am using raid-1 on 5 filesystems including root.
> The only problem I have is a failed-busy message bringing down my root
> partition when per
d write errors, which increase from
>week to week.
> >
> > Greetings, Dietmar
> >
> > >- Ursprüngliche Nachricht -
> > >Absender: [EMAIL PROTECTED]
> > >Betreff: Re: Swap on raid
> > >Empfänger: Dietmar Stein
> > >Kopie-Empfänger: [EMAIL PROTECTED]
d write errors, which increase from
>week to week.
>
> Greetings, Dietmar
>
> >- Ursprüngliche Nachricht -
> >Absender: [EMAIL PROTECTED]
> >Betreff: Re: Swap on raid
> >Empfänger: Dietmar Stein
> >Kopie-Empfänger: [EMAIL PROTECTED] , [EMAIL PROTE
cold rooms
(maybe they are to close to each other here).
Mostly (the data disks) start to have read and write errors, which increase from week
to week.
Greetings, Dietmar
>- Ursprüngliche Nachricht -
>Absender: [EMAIL PROTECTED]
>Betreff: Re: Swap on raid
>Empfänger: Die
Do other people have opinions on the "Lifetime" MTBF of a harddrive... My
experience is about 15000 hours continuous operation.
I've seen manufacturers claim 30 hours MTBF, but that's not realistic
in my experience... mabe 3 in a more controlled environment with good
aircon etc
Any
Hi
Ok - I understand what you are meaning; I think we have just different
opinions towards lifetime of a harddrive.
Maybe, I will go on using only one disk for swap - but it is interesting
seeing other opinions concerning lifetime of a hdd and security.
Greetings, Dietmar
Luca Berra wrote:
>
>
On Mon, May 10, 1999 at 07:26:53PM +0200, Dietmar Stein wrote:
> Hi
>
> At work we got much HP-Workstations and -Servers; everyone got a
> swap-partition which is of same size as physical memory (or even
> bigger).
hp-ux uses swap partitions as a dump device, something i'd love
to see on linux sy
Hi
I know what "swapoff -a" will do if there is data laying on the
swap-partition; but the intention should be to have _NO_ processes (or
whatever) being swapped out.
At work we got much HP-Workstations and -Servers; everyone got a
swap-partition which is of same size as physical memory (or even
No matter how small the ammount of data in the swap partition, the system
is likley to hang if it cannot be read...
If you have swap, it must be raid if you don't want the machine to fail...
but it's not all that much space...
On Mon, 10 May 1999, Dietmar Stein wrote:
> Hi
>
> I know what "sw
Hi,
You can run a system without a swap device. But if you do 'swapoff -a'
_after_ a swap device failure, you are dead (if swap had any virtual
data stored in it.)
'swapoff -a' copies virtual data stored in the swap device to physical
memory before closing the device. This is much different than
Paul Jakma <[EMAIL PROTECTED]> writes:
> We know raid1 works, but would swap on raid5? i hope it would, as
> raid5 is less wasteful of disk space than raid1.
But the couple of hundred megs you need for swap (at maximum) don't
really amount to anything in a big system. raid1 is faster than
raid5.
etmar
>- Ursprüngliche Nachricht -
>Absender: [EMAIL PROTECTED]
>Betreff: Re: Swap on raid
>Empfänger: Dietmar Stein
>Kopie-Empfänger: [EMAIL PROTECTED]
>Datum: 09. Mai 1999 21:09
>
> On Sun, 9 May 1999, Dietmar Stein wrote:
>
> Hi
>
> A question in between:
On Sun, 9 May 1999, Dietmar Stein wrote:
Hi
A question in between: what sense does it make to have the swap onto
raid?
I think, that moment your machine starts swapping you´ll get some
performance problems which wouldn't be solved by using "raid-swap"
instead of swap on a single
dies
on a non-redundant system.
Steve
- Original Message -
From: Dietmar Stein <[EMAIL PROTECTED]>
To: Paul Jakma <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Sunday, May 09, 1999 12:30
Subject: Re: Swap on raid
> Hi
>
> A question in between: what sense do
On Sun, 9 May 1999, Dietmar Stein wrote:
>
> A question in between: what sense does it make to have the swap onto
> raid?
>
If the swap partition becomes inaccessible, the machine crashes. that
means if a disk goes down with a swap partition on it, you are dead.
If the partition is on "raid"
Hi
A question in between: what sense does it make to have the swap onto
raid?
I think, that moment your machine starts swapping you´ll get some
performance problems which wouldn't be solved by using "raid-swap"
instead of swap on a single disk or whatever. Think of the meaning of
swap (increasin
On Sun, 9 May 1999, Gulcu Ceki wrote:
On the other hand, if the intent is higher reliability, then one can
swap on a RAID-1 partition.
i wonder, can you have your swap on a raid5 partition? raid-1 seems
a bit of a waste of hdd space.
--
Paul Jakma
[EMAIL PROTECTED] http://hibernia.c
o: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Sunday, May 09, 1999 06:39
Subject: Re: Swap on raid
>
> Hi,
>
> Having read Jabob's Software-RAID HOWTO (0.90.2 - alpha 27th of
> February 1997), I learned that you are not supposed to swap on a raid
> part
Hi,
Having read Jabob's Software-RAID HOWTO (0.90.2 - alpha 27th of
February 1997), I learned that you are not supposed to swap on a raid
partition. You can make the kernel stripe swap on different devices if
the same priority is given in the fstab file.
On the other hand, if the intent is high
Stephen C. Tweedie wrote:
> Hi,
>
> On Wed, 14 Apr 1999 21:59:49 +0100 (BST), A James Lewis
<[EMAIL PROTECTED]>
> said:
>
> > It wasn't a month ago that this was not possible because it needed
to
> > allocate memory for the raid and couldn't because it needed to swap
to
> > do it? Was I imagini
> Hi again,
> I have done a small test with a raid-1 swap partition. I have filled up
> memory so that the system swaps
> to the raid swap partition with a little test program and the system
> worked, top shows 800M of swap used
> and still going. Does this tell me that it will always work? Or
Hi,
On Wed, 14 Apr 1999 21:59:49 +0100 (BST), A James Lewis <[EMAIL PROTECTED]>
said:
> It wasn't a month ago that this was not possible because it needed to
> allocate memory for the raid and couldn't because it needed to swap to
> do it? Was I imagining this or have you guys been working too
Hi,
On Wed, 14 Apr 1999 15:32:40 -0400, "Joe Garcia" <[EMAIL PROTECTED]> said:
> Swapping to a file should work, but if I remember correctly you get
> horrible performance.
Swap-file performance on 2.2 kernels is _much_ better.
--Stephen
Hi,
On 15 Apr 1999 00:13:48 -, <[EMAIL PROTECTED]> said:
> AFAIK, the swap code uses raw file blocks on disk, rather than passing
> through to vfs, cause you dont want to cache swap accesses, think
> about it :)
Sort of correct. It does bypass most of the VFS, but it does use the
standard
Helge Hafting wrote:
> Why do you want to swap onto raid?
>
> Creating ordinary swap partitions with equal priority on
> several drives will achieve the same speedup as far as I know,
> as the kernel will spread swapping across all the swap partitions.
>
> This achieves the same speedup as raid-0
Hi again,
I have done a small test with a raid-1 swap partition. I have filled up
memory so that the system swaps
to the raid swap partition with a little test program and the system
worked, top shows 800M of swap used
and still going. Does this tell me that it will always work? Or are there
s
> swap running on raid then, if it works at all, is not actually
> protecting you. the swap code in the kern is capable of doing
> striping automatically if you have two swap partitions.
>
Yes it does. If one of two swap partitions goes down on non-raid
drives, the kernel locks up and you loose
Hi!
On 15 Apr 1999 [EMAIL PROTECTED] wrote:
> AFAIK, the swap code uses raw file blocks on disk, rather than passing
> through to vfs, cause you dont want to cache swap accesses, think about
> it :)
>
> this is how swap can work on a partition or a file, cause at swapon
> time, the blocks are
Osma Ahvenlampi <[EMAIL PROTECTED]> said:
> Ingo Molnar <[EMAIL PROTECTED]> writes:
> > > > it does work for me (i do not actually use it as such, but i\'ve done
some
> > > > stresstesting under heavy load). Let me know if you find any problems.
> > > Hmm? Since when does swapping work on rai
Errr?
It wasn't a month ago that this was not possible because it needed to
allocate memory for the raid and couldn't because it needed to swap to do
it? Was I imagining this or have you guys been working too hard!
Either way, brill!
James
On Wed, 14 Apr 1999, Ingo Molnar wrote:
>
> On 14
On Wed, Apr 14, 1999 at 05:44:47PM +0300, Osma Ahvenlampi wrote:
> Ingo Molnar <[EMAIL PROTECTED]> writes:
> > > > it does work for me (i do not actually use it as such, but i've done some
> > > > stresstesting under heavy load). Let me know if you find any problems.
> > > Hmm? Since when does sw
Swapping to a file should work, but if I remember correctly you get horrible
performance.
Joe
> -Original Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of [EMAIL PROTECTED]
> Sent: Wednesday, April 14, 1999 9:36 AM
> To: Linux Raid
> Subject: Swap on raid
>
>
Hello All, Cool now when do we get the new alpha-lilo
alpha-silo, alpha-milo tools to support the alpha-raid ?
I know, I know, 'hack away...' tnx, JimL
On Wed, 14 Apr 1999, Ingo Molnar wrote:
> On 14 Apr 1999, Osma Ahvenlampi wrote:
> > Ingo Molnar <[EMAIL PROTECTED]>
Ingo Molnar <[EMAIL PROTECTED]> writes:
> > > it does work for me (i do not actually use it as such, but i've done some
> > > stresstesting under heavy load). Let me know if you find any problems.
> > Hmm? Since when does swapping work on raid-1? How about raid-5?
> i've tested it on RAID5, swapp
On 14 Apr 1999, Osma Ahvenlampi wrote:
> Ingo Molnar <[EMAIL PROTECTED]> writes:
> > it does work for me (i do not actually use it as such, but i've done some
> > stresstesting under heavy load). Let me know if you find any problems.
>
> Hmm? Since when does swapping work on raid-1? How about
Ingo Molnar <[EMAIL PROTECTED]> writes:
> it does work for me (i do not actually use it as such, but i've done some
> stresstesting under heavy load). Let me know if you find any problems.
Hmm? Since when does swapping work on raid-1? How about raid-5?
--
Osma Ahvenlampi
On Wed, 14 Apr 1999 [EMAIL PROTECTED] wrote:
> Hi folks,
> we are trying to set up a mirrored (raid-1) system for reliability
> but it is not possible according
> to the latest HOWTO to swap onto a raid volume. Is there any change on
> this?
it does work for me (i do not actually use it as
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