Re: [zfs-discuss] Bad SWAP performance from zvol
I'm not sure where this issue stands now (am just now checking mail after being out for a few days), but here are the block sizes used when the install software creates swap and dump zvols: swap: block size is set to PAGESIZE (4K for x86, 8K for sparc) dump: block size is set to 128 KB Liveupgrade should use the same characteristics, though I think there was a bug at one time where it did not. If that does not improve dump/swap zvol performance, further investigation should be done. Perhaps file a bug. Lori On 03/31/09 03:02, casper@sun.com wrote: I've upgraded my system from ufs to zfs (root pool). By default, it creates a zvol for dump and swap. It's a 4GB Ultra-45 and every late night/morning I run a job which takes around 2GB of memory. With a zvol swap, the system becomes unusable and the Sun Ray client often goes into "26B". So I removed the zvol swap and now I have a standard swap partition. The performance is much better (night and day). The system is usable and I don't know the job is running. Is this expected? Casper ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Bad SWAP performance from zvol
>casper@sun.com said: >> I've upgraded my system from ufs to zfs (root pool). >> By default, it creates a zvol for dump and swap. >> . . . >> So I removed the zvol swap and now I have a standard swap partition. The >> performance is much better (night and day). The system is usable and I >> don't know the job is running. >> >> Is this expected? > >If you're using Solaris-10U6 to migrate, the early revisions of liveupgrade >would create swap and dump zvols that have some different properties than >what S10U6 Jumpstart creates. On x86 here, the swap zvol ends up with 4k >volblocksize when you Jumpstart install, but liveupgrade sets it to 8k (which >does not match the system page-size of 4k). Solaris Nevada s110 or some such. >Sorry I can't report on whether zvol swap is slower than UFS swap slice >for us here; None of our ZFS-root systems have done any significant >swapping/paging as far as I can tell. Well, you can make them page, or not? Casper ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Bad SWAP performance from zvol
casper@sun.com said: > I've upgraded my system from ufs to zfs (root pool). > By default, it creates a zvol for dump and swap. > . . . > So I removed the zvol swap and now I have a standard swap partition. The > performance is much better (night and day). The system is usable and I > don't know the job is running. > > Is this expected? If you're using Solaris-10U6 to migrate, the early revisions of liveupgrade would create swap and dump zvols that have some different properties than what S10U6 Jumpstart creates. On x86 here, the swap zvol ends up with 4k volblocksize when you Jumpstart install, but liveupgrade sets it to 8k (which does not match the system page-size of 4k). The other difference I noticed was the dump zvol from Jumpstart install has 128k volblocksize, but early S10U6 liveupgrade set it to 8k, which makes crash-dumps incredibly slow (should you have one). I know that subsequent LU patches have fixed the dump zvol volblocksize, but am not sure if the swap zvol has been updated in a LU patch. Sorry I can't report on whether zvol swap is slower than UFS swap slice for us here; None of our ZFS-root systems have done any significant swapping/paging as far as I can tell. $ zfs get volsize,referenced rpool/swap NAMEPROPERTYVALUE SOURCE rpool/swap volsize 4.00G - rpool/swap referenced 105M- $ Regards, Marion ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Bad SWAP performance from zvol
I've upgraded my system from ufs to zfs (root pool). By default, it creates a zvol for dump and swap. It's a 4GB Ultra-45 and every late night/morning I run a job which takes around 2GB of memory. With a zvol swap, the system becomes unusable and the Sun Ray client often goes into "26B". So I removed the zvol swap and now I have a standard swap partition. The performance is much better (night and day). The system is usable and I don't know the job is running. Is this expected? Casper ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
