Btrfs-progs: Add hot data support in mkfs
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From: Andrey Panin on 13 Aug 2010 09:20 On 224, 08 12, 2010 at 05:29:37PM -0500, bchociej(a)gmail.com wrote: > From: Ben Chociej <bchociej(a)gmail.com> > > Modified mkfs.btrfs to add hot data relocation option (-h) which > preallocates BTRFS_BLOCK_GROUP_DATA_SSD and > BTRFS_BLOCK_GROUP_METADATA_SSD at mkfs time for future use by hot data > relocation code. Also added a userspace function to detect whether a > block device is an SSD by reading the sysfs block queue rotational flag. IMHO this policy is too inflexible. What if I have large array of slow SATA disks and some fast SAS ones ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Tomasz Torcz on 13 Aug 2010 10:20 On Fri, Aug 13, 2010 at 05:14:22PM +0400, Andrey Panin wrote: > On 224, 08 12, 2010 at 05:29:37PM -0500, bchociej(a)gmail.com wrote: > > From: Ben Chociej <bchociej(a)gmail.com> > > > > Modified mkfs.btrfs to add hot data relocation option (-h) which > > preallocates BTRFS_BLOCK_GROUP_DATA_SSD and > > BTRFS_BLOCK_GROUP_METADATA_SSD at mkfs time for future use by hot data > > relocation code. Also added a userspace function to detect whether a > > block device is an SSD by reading the sysfs block queue rotational flag. > > IMHO this policy is too inflexible. What if I have large array of slow SATA > disks and some fast SAS ones ? I'm hoping that this is just first cut, and future versions will have options. For now, it is totally unusable without a way of using mirrored SSD for hot data. Ideally, hot storage devices should be online selectable and changeable. -- Tomasz Torcz 72->| 80->| xmpp: zdzichubg(a)chrome.pl 72->| 80->| -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Ben Chociej on 13 Aug 2010 10:20
On Fri, Aug 13, 2010 at 9:08 AM, Tomasz Torcz <tomek(a)pipebreaker.pl> wrote: > On Fri, Aug 13, 2010 at 05:14:22PM +0400, Andrey Panin wrote: >> On 224, 08 12, 2010 at 05:29:37PM -0500, bchociej(a)gmail.com wrote: >> > From: Ben Chociej <bchociej(a)gmail.com> >> > >> > Modified mkfs.btrfs to add hot data relocation option (-h) which >> > preallocates BTRFS_BLOCK_GROUP_DATA_SSD and >> > BTRFS_BLOCK_GROUP_METADATA_SSD at mkfs time for future use by hot data >> > relocation code. �Also added a userspace function to detect whether a >> > block device is an SSD by reading the sysfs block queue rotational flag. >> >> IMHO this policy is too inflexible. What if I have large array of slow SATA >> disks and some fast SAS ones ? > > �I'm hoping that this is just first cut, and future versions will have options. > For now, it is totally unusable without a way of using mirrored SSD for > hot data. > �Ideally, hot storage devices should be online selectable and changeable. > > -- > Tomasz Torcz � � � � � � � � � � � � � � � � � � � � � � � � � � � 72->| � 80->| > xmpp: zdzichubg(a)chrome.pl � � � � � � � � � � � � � � � � � � � � �72->| � 80->| > > This is very much just a first cut. Our goal here was to get a lot of the legwork and experimental coding out of the way to enable to Btrfs to *fully* tackle heterogeneous storage in the future. BC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |