Messages in this thread |  | | Date | Mon, 19 Mar 2012 19:38:04 +0000 (GMT) | From | Holger Kiehl <> | Subject | Re: [patch v2 0/6] Add TRIM support for raid linear/0/1/10 |
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Hello,
On Fri, 16 Mar 2012, Shaohua Li wrote:
> The patches add TRIM support for raid linear/0/1/10. I'll add TRIM support for > raid 4/5/6 later. The implementation is pretty straightforward and > self-explained. > > v1->v2: > 1. fixed a checking issue > 2. dropped discard request plug and replace it with no discard merege, because > current SCSI layer can't handle discard request merge. > Have tested TRIM patches on three different systems with the following hardware/ setup:
1) root mounted on a raid1 over two SAS SSD's (200GB) and /home partition on a raid0 over a fusionio ioDrive Duo. Is very new and seen very little usage.
2) root and /home mounted on a raid0 over two Intel X25 Postville (160GB) connected to a Intel P55 Express chipset. Has seen very heavy usage for approx. 2 years.
3) root and /home mounted on a raid0 over three OCZ-VERTEX2 (120GB) connected via ICH7 south bridge. Has seen mild usage for approx. 1.5 years.
Made the following observations when running my own benchmark which copies around a lot of small files and deletes them. The benchmark on all systems was always run only on the /home partition ie. on a raid0.
For system 1) there is hardly any measurable differnce whether discard is enabled or not (~29000 files per second).
On system 2) the performance drops from 6500->3700 files per second, but under normal usage one does not notice any difference.
System 3) has problems during boot, it is so slow that some operations receive a timeout during boot:
udevd[474]: timeout '/sbin/blkid -o udev -p /dev/md0' udevd[474]: timeout: killing '/sbin/blkid -o udev -p /dev/md0' [866] systemd[1]: dev-md3.swap activation timed out. Stopping.
Even removing discard does not help and the above errors happen during boot and booting takes a long time.
The performance in the benchmark drops from 4000->600 files per second.
Regards, Holger
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